Question: A 42-year-old woman is enrolled in a randomized controlled trial to study cardiac function in the setting of several different drugs. She is started on verapamil and instructed to exercise at 50% of her VO2 max while several cardiac parameters are being measured. During this experiment, which of the following represents the relative conduction speed through the heart from fastest to slowest?

AV node > ventricles > atria > Purkinje fibers

Purkinje fibers > ventricles > atria > AV node

Purkinje fibers > AV node > ventricles > atria

Answer: Purkinje fibers > atria > ventricles > AV node

Explanation:
The conduction velocity of the structures of the heart are in the following order: Purkinje fibers > atria > ventricles > AV node. A calcium channel blocker such as verapamil would only slow conduction in the AV node.

The conduction velocity of cardiac tissue is determined by a wide variety of factors, including the number and identity of various ion channels, the number and type of gap junctions, and the size and composition of muscle fibers. Conduction through the Purkinje system is the fastest within the heart, allowing for coordinated contraction of the ventricles, and atrial muscle conducts faster than ventricular muscle. Conduction through the AV node is the slowest, to allow the ventricles enough time to fill with blood.

Bonke et al. review the evidence regarding the conduction velocity of parts of the heart. They discuss how the AV node is slower than the SA node. They recommend understanding how different parts of the heart conducts electricity.

Incorrect Answers:
Answers A-C & E: These choices do not correspond to the correct conduction velocities in each part of the cardiac conduction system. A calcium channel blocker would not change the relative velocities of conduction in Purkinje fibers, atria, and ventricles.

Bullet Summary:
The conduction velocity through the heart in order of speed is Purkinje fibers > atria > ventricles > AV node.


Question: A 9-year-old girl presents to the emergency department with a fever and a change in her behavior. She presented with similar symptoms 6 weeks ago and was treated for an Escherchia coli infection. She also was treated for a urinary tract infection 10 weeks ago. Her mother says that last night her daughter felt ill, and her condition has been worsening. Her daughter experienced a severe headache and had a stiff neck. This morning she was minimally responsive, vomited several times, and produced a small amount of dark cloudy urine. The patient was born at 39 weeks and met all her developmental milestones. She is currently up to date on her vaccinations and did not have infections during early childhood. Her parents are divorced and her father has noted she does not seem to get sick when he takes care of her. Her temperature is 99.5°F (37.5°C), blood pressure is 60/35 mmHg, pulse is 190/min, respirations are 33/min, and oxygen saturation is 98% on room air. The patient is started on intravenous fluids, vasopressors, and broad-spectrum antibiotics. Which of the following is the most appropriate underlying explanation for this patient's presentation?

Answer: Intentional contamination

Explanation:
This patient is presenting with repeat sepsis, which is uncommon in a pediatric patient with no significant medical history. This abnormal concentration of infections when the patient is with her mother suggests a diagnosis of intentional contamination.

Factitious disorder by proxy (formerly Munchausen syndrome) occurs when 1 individual creates symptoms in another for attention. Typically, this is a parent feigning or creating symptoms in a child in order to receive the psychiatric gain of attention from healthcare personnel. The patient should be treated and removed from the parents as this is considered child abuse. Factitious disorder by proxy should be suspected in any pediatric patient who has repeat infections that are atypical or not expected epidemiologically. Patients should also be evaluated for organic causes of symptoms such as immunodeficiency syndromes.

Abeln and Love review the evidence regarding the diagnosis of factitious disorder by proxy. They discuss how these disorders have high morbidity and mortality when not accurately recognized. They recommend paying attention to red flags such as abnormal constellations of symptoms.

Incorrect Answers:
Answer A: Gastroenteritis would present with nausea, vomiting, and diarrhea; however, it would not present with sepsis routinely. Gastroenteritis does not best explain the most likely underlying cause of this patient's presentation.

Answer B: Immunodeficiency such as severe combined immunodeficiency (SCID) would present with lifelong infections from birth that are bacterial, viral, and fungal. Immunodeficiency would not present with repeat infections in a pediatric patient only when they are with one patient.

Answer D: Meningitis would present with headache, altered mental status, and meningeal signs. In the setting of repeat sepsis in a healthy pediatric patient, intentional contamination is more likely. Similarly, an absence of photophobia and no further history/physical exam supporting this diagnosis suggests an alternative diagnosis.

Answer E: Urinary tract infection would present with dysuria rather than repeat episodes of sepsis. Though a urinary tract infection could lead to sepsis, this would be rare and more likely to occur in an immunosuppressed patient, the elderly, or a neonate. UTIs are a common cause of infection and fever in pediatric patients.

Bullet Summary:
Factitious disorder by proxy occurs when 1 individual feigns or creates symptoms in another.


Question: A 1-year-old girl is brought to a neurologist due to increasing seizure frequency over the past 2 months. She recently underwent a neurology evaluation which revealed hypsarrhythmia on electroencephalography (EEG) with a mix of slow waves, multifocal spikes, and asynchrony. Her parents have noticed the patient occasionally stiffens and spreads her arms at home. She was born at 38-weeks gestational age without complications. She has no other medical problems. Her medications consist of lamotrigine and valproic acid. Her temperature is 98.3°F (36.8°C), blood pressure is 90/75 mmHg, pulse is 94/min, and respirations are 22/min. Physical exam reveals innumerable hypopigmented macules on the skin and an irregularly shaped, thickened, and elevated plaque on the lower back. Which of the following is most strongly associated with this patient's condition?

Answer: Cardiac rhabdomyoma

Explanation:
This patient with a seizure disorder, ash-leaf spots (innumerable hypopigmented macules), Shagreen patch (elevated irregular plaque on the lower back), and West syndrome (hypsarrhythmia on EEG and movements consistent with infantile spasms) likely has tuberous sclerosis. Tuberous sclerosis is associated with cardiac rhabdomyomas.

Tuberous sclerosis is a neurocutaneous disorder that is inherited in an autosomal dominant fashion. Mutations in TSC1 and TSC2 lead to unregulated cell growth, leading to the formation of hamartomas in various locations. Manifestations of tuberous sclerosis include seizures (secondary to subependymal nodules and cortical dysplasia), mental retardation, renal angiomyolipomas, facial angiofibromas, mitral regurgitation, and hypomelanotic macules (ash-leaf spots). Cardiac rhabdomyoma is strongly associated with tuberous sclerosis and can lead to arrhythmias. West syndrome, which is characterized by infantile spasms, intellectual disability, and hypsarrhythmia (a chaotic mixture of high-amplitude slow waves, multifocal spikes, and intrahemispheric-interhemispheric asynchrony) on EEG, is also associated with tuberous sclerosis. Diagnosis of tuberous sclerosis is made with genetic testing. Advanced imaging (CT or MRI) may reveal cortical tubers and lesions in the third and fourth ventricles. Abdominal imaging may reveal renal angiomyolipomas. The management of seizures in tuberous sclerosis includes anti-seizure medications, though surgery may also be pursued in select cases.

Hinton et al. studied the cardiac manifestations of tuberous sclerosis. They found that cardiac rhabdomyomas can lead to arrhythmia later in life. They recommended that infantile spasms in tuberous sclerosis be treated with vigabatrin but other seizure types should be treated similar to other epileptic disorders.

Incorrect Answers:
Answer B: Glaucoma may occur in patients with Sturge-Weber syndrome, which is characterized by "tram-track" calcifications in the brain, port-wine stains of the face, mental retardation, and epilepsy. Diagnosis is with MRI of the brain with contrast to demonstrate leptomeningeal vascular malformations that are characteristic of the disease.

Answer C: Optic glioma is associated with neurofibromatosis type 1 (NF1), which presents with hyperpigmented macules (cafe-au-lait spots), axillary freckling, and cutaneous neurofibromas. Neurofibromas in NF1 may also grow on peripheral nerves, leading to malignant peripheral nerve sheath tumors. Lisch nodules, or benign growths of the iris, may also be seen in NF1. Diagnosis of NF1 is clinical, but can be aided by genetic testing.

Answer D: Polyostotic fibrous dysplasia is associated with McCune-Albright syndrome. Polyostotic fibrous dysplasia causes fibrous tissue in bones, leading to growth abnormalities and pathologic fractures. McCune-Albright syndrome is also associated with cafe-au-lait macules, which have irregular borders, and endocrine abnormalities such as precocious puberty and hyperthyroidism. Diagnosis is supported with endocrine tests as well as genetic testing.

Answer E: Renal cell carcinoma is associated with Von-Hippel-Lindau syndrome (VHL), which presents with tumors arising in multiple organs. Patients with VHL present with hemangioblastomas in the brain, spinal cord, cerebellum, and retina, and pheochromocytoma. Pheochromocytomas release catecholamines, leading to episodic hypertension, diaphoresis, and palpitations. Diagnosis of VHL is with genetic testing.

Bullet Summary:
Tuberous sclerosis has numerous manifestations including seizures, angiofibromas, mitral regurgitation, renal angiomyolipoma, ash-leaf spots, mental retardation, and cardiac rhabdomyoma.


Question: A 17-year-old boy presents to his primary care physician with a chief concern of "bad" skin that has not improved despite home remedies. The patient has had lesions on his face that have persisted since he was 13 years of age. He has a diet high in refined carbohydrates and has gained 20 pounds since starting high school. Physical exam is notable for the findings in Figure A. The patient is started on benzoyl peroxide and topical retinoids. He returns 1 month later stating that his symptoms are roughly the same. Which of the following is the most appropriate next step in management?

Continue current therapy for 1 more month

Answer: Topical antibiotics

Explanation:
This patient is presenting with persistent acne vulgaris that is refractory to topical benzoyl peroxide and retinoids. The next step in management is topical antibiotics.

Acne vulgaris is caused by blockage or outlet obstruction of the pilosebaceous unit. It presents with erythema, pustules, and comedones typically in young men going through puberty. Risk factors include stress, excessive sweating, greasy skin care products, and steroid use. The management of acne vulgaris, in order, is to start with topical benzoyl peroxide and topical retinoids, topical antibiotics, oral antibiotics, and isoretinoin. It is important to try a therapy for a proper duration before switching to a more invasive therapy.

Eichenfield et al. review the evidence regarding the treatment of patients with acne vulgaris. They discuss how this disease can be treated with benzoyl peroxide. They recommend using antibiotics or isotretinoin for refractory cases.

Figure/Illustration A is a clinical photograph demonstrating diffuse comedones over the forehead (red circle). These findings are classically seen in patients with acne vulgaris.

Incorrect Answers:
Answer A: Continuing current therapy for 1 more month is unnecessary as this patient's symptoms have not improved at all with 1 month of therapy. Continuing current therapy would be appropriate if the patient had only tried therapy for a few days.

Answer B: Dietary interventions have not been shown to improve outcomes in acne vulgaris. Stopping illicit substances such as performance enhancing steroids can be effective in reducing acne symptoms but there is no evidence this patient has been using steroids.

Answer C: Isoretinoin is the last-line therapy for acne vulgaris. It should not be given to pregnant women as it is teratogenic. Women taking isoretinoin should be on reliable birth control. Topical and oral antibiotics should be used first.

Answer D: Oral antibiotics would be indicated after topical antibiotics fail. Topical antibiotics should be tried first as these do not have systemic side effects.

Bullet Summary:
The management of acne vulgaris is to start with topical benzoyl peroxide and topical retinoids, followed by topical antibiotics, oral antibiotics, and isoretinoin in increasing order of severity.


Question: A 55-year-old woman is brought to the emergency department by her husband with a 1 hour history of an unremitting headache. The headache started suddenly while she was eating dinner and she says it feels like the “worst headache of my life.” An emergent CT scan of the head without contrast confirms the diagnosis, and a CT angiogram identifies the source of bleeding. The patient undergoes surgical management of her condition. On hospital day 3, she is found to be disoriented to person, place, and time. She also develops nausea and vomiting. Her medical problems consist of heart failure for which she takes furosemide, spironolactone, and metoprolol, which were continued at admission. Her temperature is 99.6°F (37.6°C), blood pressure is 100/60 mmHg, pulse is 112/min, and respirations are 16/min. Physical examination shows poor skin turgor. Capillary refill time is 4 seconds. Serum laboratory results are shown below: Na+: 120 mEq/L Cl-: 92 mEq/L K+: 3.9 mEq/L HCO3-: 26 mEq/L BUN: 32 mg/dL Creatinine: 1.0 mg/dL Serum osmolality is 265 mEq/L and urine osmolality is 340 mEq/L. Urine sodium is 44 mEq/L. Which of the following is the most likely diagnosis?

Answer: Cerebral salt wasting

Explanation:
This patient presents with a subarachnoid hemorrhage (“worst headache of my life”) which is treated and then subsequently develops nausea, vomiting, and altered mental status with reduced serum sodium concentration, indicative of symptomatic hyponatremia. In the setting of serum hypo-osmolality, urine hyper-osmolality, urine sodium concentration > 20 mEq/L, and hypovolemia (low blood pressure, decreased skin turgor, and prolonged capillary refill), this is indicative of cerebral salt wasting.

The mechanism of cerebral salt wasting is unclear, although some hypotheses point to increased release of brain natriuretic peptide after injury leading to suppression of renal sodium reabsorption, or sympathetic nervous system injury resulting in an impaired renin response. Patients classically present several days after cerebral injury or neurosurgery with hypovolemic hyponatremia and hypochloremia. Water retention results in serum hypo-osmolality, hyponatremia, and hypochloremia with urine hyper-osmolality and increased urine sodium excretion. In patients with prolonged cerebral salt wasting, hypokalemia can also occur (potassium may be normal in acute states). Treatment in mild or moderate cases consists of normal saline infusion to correct both volume status and hyponatremia. Treatment in severe cases consists of hypertonic saline. During correction, serum sodium must be monitored closely to prevent central pontine myelinolysis.

Cui et al. describe the differences between syndrome of inappropriate anti-diuretic hormone (SIADH) and cerebral salt wasting. They discuss how volume status serves as the key differentiator between these conditions. They recommend paying closer attention to total body electrolyte balance in understanding these conditions.

Incorrect Answers:
Answer A: Addison disease, also known as primary adrenal insufficiency, results in salt wasting due to decreased mineralocorticoid activity. Because of reduced aldosterone release, patients also have hyperkalemia and metabolic acidosis. In contrast, this patient’s potassium and bicarbonate levels are normal. Treatment is with steroids.

Answer C: Diuretic overuse is occasionally observed in patients using loop diuretics. Overuse of loop diuretics can cause hyponatremia, hypokalemia, and hypochloremia. Metabolic alkalosis is commonly seen due to volume contraction. Cerebral salt wasting is more likely in this patient presenting after a recent cerebral injury. Treatment is the cessation of the causative medication.

Answer D: Primary polydipsia can cause symptomatic hyponatremia. The urine would be maximally diluted (urine osmolality < 100 mEq/L) due to an appropriate physiological response to hyponatremia and excess free water intake. Treatment is cessation of excessive water consumption.

Answer E: Syndrome of inappropriate anti-diuretic hormone (SIADH) presents with identical findings as cerebral salt wasting with the exception of euvolemia as opposed to hypovolemia. An assessment of volume status is essential to differentiate. This patient has clear signs of hypovolemia. Treatment of SIADH is fluid restriction followed by ADH inhibitors, if needed.

Bullet Summary:
Cerebral salt wasting presents with hyponatremia, hypochloremia, and hypovolemia in the setting of recent cerebral injury or neurosurgery.


Question: A 2-week-old boy is evaluated by his pediatrician for abnormal feet. The patient was born at 39 weeks via vaginal delivery to a G1P1 29-year-old woman. The patient has been breastfeeding and producing 5 stools/day. He is otherwise healthy. His temperature is 99.5°F (37.5°C), blood pressure is 60/38 mmHg, pulse is 150/min, respirations are 24/min, and oxygen saturation is 98% on room air. A cardiopulmonary exam is notable for a benign flow murmur. A musculoskeletal exam reveals the findings shown in Figure A. Which of the following is the most appropriate next step in management?

Answer: Serial casting

Explanation:
This patient is presenting with talipes equinovarus (congenital clubfoot) for which the most appropriate initial step in management is serial casting using the Ponseti method.

Talipes equinovarus is described clinically as a foot that is cavus, adductus, varus, and equinus. Cavus occurs when the forefoot is pronated relative to the hindfoot. Adductus occurs when the forefoot is medially deviated compared to the hindfoot. Varus occurs when the heel is medially deviated compared to the ankle. Finally, equinus occurs when the ankle rests in a plantarflexed position. The most appropriate initial step in management for this condition is serial casting using the Ponseti method. Cases that are refractory to this intervention are treated with surgical interventions such as split tibialis anterior transfer.

Cady et al. review the evidence regarding the treatment of clubfeet. They discuss how the Ponseti method is now the standard of care in the treatment of this disorder. They recommend early diagnosis and treatment of these patients.

Figure/Illustration A is a clinical photograph that demonstrates cavus, adductus, equinus, and varus positioning of the foot (red circles). This appearance is classically seen in congenital talipes equinovarus.

Incorrect Answers:
Answer A: Botulinum toxin injections are often used to treat spasticity and tension headaches; however, they are not indicated for the treatment of talipes equinovarus.

Answer B: Reassurance and reassessment in 1 month would be inappropriate management and could lead to permanent sequelae. Patients require immediate treatment with serial casting in order to correct the deformity.

Answers 4 & 5: Surgical interventions are reserved for cases of clubfoot that are refractory to stretching and serial casting. A percutaneous Achilles tenotomy is part of the Ponseti method but tendon transfers and releases are reserved for recurrent cases.

Bullet Summary:
The most appropriate initial step in management for congenital clubfoot (talipes equinovarus) is serial casting using the Ponseti method.


Question: A 1-month-old girl presents to her pediatrician with her mother. The patient was born at 38 weeks gestation via Caesarean section for cervical incompetence. The patient’s mother has no complaints. The child had a runny nose and cough for a few days last week. The patient’s mother endorses decreased appetite during the aforementioned illness which has now returned to baseline. The patient’s family history is significant for an older brother with glucose-6-phosphate dehydrogenase (G6PD) deficiency and a maternal uncle with cirrhosis secondary to chronic hepatitis B. On physical exam, the patient has scleral icterus and dark urine staining her diaper. Laboratory testing reveals the following: Serum: Na+: 137 mEq/L Cl-: 102 mEq/L K+: 4.2 mEq/L HCO3-: 24 mEq/L Urea nitrogen: 12 mg/dL Glucose: 96 mg/dL Creatinine: 0.36 mg/dL Alkaline phosphatase: 146 U/L Aspartate aminotransferase (AST): 86 U/L Alanine aminotransferase (ALT): 76 U/L Total bilirubin: 4.6 mg/dL Direct bilirubin: 3.8 mg/dL Which of the following is the most likely diagnosis?

Increased enterohepatic circulation of bilirubin

Obstruction of the extrahepatic biliary tree

Answer: Obstruction of the extrahepatic biliary tree

Explanation:
This 2-month-old patient presents with jaundice, dark urine, mild transaminitis, and conjugated hyperbilirubinemia, which suggests the diagnosis of biliary atresia. Biliary atresia is characterized by obstruction of the extrahepatic biliary tree.

Biliary atresia is a progressive, obliterative disease of the extrahepatic biliary tree. It presents in the first 8 weeks of life with jaundice, acholic stools, dark urine, hepatomegaly, mild transaminitis, and conjugated hyperbilirubinemia. The definitive diagnosis is made by a cholangiogram that will demonstrate the obliteration of these ducts. Patients who are untreated experience fatal neurological defects due to kernicterus and accumulation of bilirubin in the brain. Treatment usually involves hepatoportoenterostomy (Kasai procedure), in which the duodenum is directly anastomosed to the liver. Most patients also eventually require a liver transplant.

Hartley et al. review the evidence regarding the diagnosis and treatment of patients with biliary atresia. They discuss how researchers are trying to reverse the liver fibrosis associated with this disease. They recommend early referral for a Kasai procedure or liver transplant as needed.

Incorrect Answers:
Answer A: Decreased metabolism of bilirubin occurs with enzymatic deficiencies such as those seen in Crigler-Najjar or Gilbert syndrome. Both Crigler-Najjar and Gilbert syndromes lead to unconjugated hyperbilirubinemia (much more severe in Crigler-Najjar syndrome) rather than the conjugated hyperbilirubinemia seen in this patient.

Answer B: Increased enterohepatic circulation describes the pathophysiology underlying breast milk jaundice. Breast milk jaundice classically peaks in the first 2 weeks of life and leads to unconjugated rather than conjugated hyperbilirubinemia. Treatment is usually supportive and patients can typically continue to breastfeed.

Answer C: Increased production of bilirubin can occur in hemolytic diseases such as G6PD deficiency or hereditary spherocytosis. These conditions would similarly lead to an unconjugated hyperbilirubinemia. Treatment is with addressing the underlying anemia with possible transfusion or splenectomy.

Answer E: Obstruction of the intrahepatic biliary tree describes Alagille syndrome, in which patients have a paucity of interlobular bile ducts. Alagille syndrome is less common than biliary atresia and usually presents with other associated features, such as short stature, dysmorphic facies, ocular findings, and cardiac or renal anomalies. Treatment is with ursodiol.

Bullet Summary:
Biliary atresia presents in the first 8 weeks of life with jaundice and conjugated hyperbilirubinemia.


Question: A newborn boy is evaluated in the hospital nursery 2 hours after birth. The patient was born at 39 weeks of gestation to a 30-year-old primigravid via vaginal delivery. The patient’s mother received routine prenatal care and the pregnancy was uncomplicated. The patient’s anatomy ultrasound at 20 weeks of gestation was unremarkable. The patient’s mother denies any family history of genetic diseases. The patient’s APGAR scores were notable for poor muscle tone at both 1 and 5 minutes of life. The patient’s birth weight is 2.6 kg (5 lb 11 oz), which is at the 5th percentile. His height and head circumference are in the 15th and 3rd percentile, respectively. His temperature is 97.1°F (36.2°C), blood pressure is 57/42 mmHg, pulse is 140/min, and respirations are 38/min. On physical exam, the patient has a wide nasal bridge, down slanting palpebral fissures, and widely spaced eyes. He has good respiratory effort with a high-pitched cry. This patient is most likely to have experienced a deletion on which of the following chromosomes?

Answer: 5p

Explanation:
This patient presents with a characteristic mew, microcephaly, hypertelorism, wide nasal bridge, and hypotonia, which suggests a diagnosis of cri-du-chat syndrome. Cri-du-chat syndrome is caused by a deletion on chromosome 5p.

Cri-du-chat syndrome is most commonly caused by a de novo partial deletion of chromosome 5p. Other cases may be caused by a parental translocation involving the relevant section of chromosome 5p. Patients present with a mew-like cry, microcephaly, hypertelorism, down slanting palpebral fissures, a broad nasal bridge, low-set ears, low birth weight, hypotonia, and intellectual disability. The cat-like cry usually resolves by 2 years of age. Treatment is supportive though some patients may have cardiac abnormalities that require surgical intervention.

Cerruti Mainardi reviews the evidence regarding the etiology and diagnosis of patients with Cri-du-chat syndrome. She discusses how the diagnosis is mostly made clinically at this time. She recommends karyotype and FISH studies for those with ambiguous features.

Incorrect Answers:
Answer A: A deletion on chromosome 4p causes Wolf-Hirshhorn syndrome, which presents with growth restriction, microcephaly, congenital heart disease, severe intellectual disability and dysmorphic "Greek warrior helmet" facies of a high forehead, prominent glabella, arched eyebrows, hypertelorism, and epicanthal folds. Treatment is supportive though some patients may require surgical intervention for heart defects.

Answer C: A deletion on chromosome 5q results in Sotos syndrome, a pediatric overgrowth disorder characterized by an increase in head circumference, hypotonia, delayed acquisition of motor skills, and mild intellectual disability.

Answer D: A deletion on chromosome 7q may results in Williams syndrome, which presents with dysmorphic, “elfin” facies, global developmental delay with a hypersocial personality, and supravalvular aortic stenosis. Treatment is supportive though some patients will require surgical intervention for aortic stenosis.

Answer E: A deletion on chromosome 15q may cause either Prader-Willi syndrome or Angelman syndrome, depending on whether the deletion affects the maternal or paternal chromosome. Prader-Willi syndrome classically presents with dysmorphic facies, hyperphagia, and hypogonadism. Angelman syndrome classically presents with intellectual disability, frequent smiling or laughing, and gait ataxia. Treatment is supportive with seizure control for those who develop seizures.

Bullet Summary:
Cri-du-chat syndrome (presents with a characteristic mew, microcephaly, hypertelorism, wide nasal bridge, and hypotonia) is most commonly caused by a deletion on chromosome 5p.


Question: A 55-year-old male bodybuilder presents to the emergency department with weakness of his right arm. The patient states he has experienced these symptoms for a few weeks; however, today his hand felt so weak he dropped his cup of tea. The patient has a medical history of diabetes. He drinks 2-7 alcoholic drinks per day and has smoked 2 packs of cigarettes per day since he was 25. The patient uses anabolic steroids. He has lost 17 pounds since he last came to the emergency department 1 month ago. His temperature is 99.5°F (37.5°C), blood pressure is 177/108 mmHg, pulse is 90/min, respirations are 17/min, and oxygen saturation is 98% on room air. Physical exam reveals decreased sensation in the right arm and 2/5 strength in the right arm and 5/5 strength in in the left arm. The patient states that he is experiencing a dull aching and burning pain in his right arm during the exam. Symptoms are not changed with changes in head and neck position. Which of the following is the most likely diagnosis?

Answer: Apical lung tumor

Explanation:
This patient is presenting with unilateral upper extremity paresthesia and weakness suggestive of compression of the neurovascular structures of the upper extremity secondary to an apical lung tumor.

An apical lung tumor can compress the neurovascular structures in its proximity and cause pain, numbness, and weakness of the ipsilateral arm. A Horner syndrome can also be observed with compression of the sympathetic chain leading to ipsilateral miosis, ptosis, and anhidrosis in some cases. These malignancies typically occur in older male smokers and can be associated with symptoms such as fatigue, cough, and weight loss. Chest radiography will demonstrate an apical opacity and CT scan can confirm the size and location of the mass. Treatment is with chemotherapy and surgical excision of the tumor.

Davis and Knight review the evidence regarding the diagnosis and treatment of patients with apical lung tumors. They discuss how these tumors can be associated with brachial plexus injuries. They recommend surgical excision of these tumors if they are resectable.

Incorrect Answers:
Answer B: Brachial plexopathy could present with weakness and numbness of the ipsilateral arm but is a less likely diagnosis (and a diagnosis of exclusion). Treatment is with identification and surgical release of any underlying anatomic defects (such as compressive bands) and supportive therapy if none are found.

Answer C: Cerebral infarction (stroke) would present with sudden onset of acute neurological deficits. These would typically only affect one side of the body and would not necessarily be associated with a dull pain or numbness that is chronic. Treatment is with thrombolytics if patients meet criteria for acute therapy.

Answer D: Scalenus anticus syndrome occurs in bodybuilders or athletes with hypertrophied neck muscles that compress the brachial plexus. Symptoms are typically worsened by certain positions. Treatment is with physical therapy and surgical decompression in refractory cases.

Answer E: Subclavian steal syndrome presents with numbness, tingling, weakness in a limb, and CNS symptoms (vertigo, slurred speech, or stroke-like symptoms) that are worsened with activity and relieved with rest. Treatment is with vascular intervention to restore blood flow.

Bullet Summary:
Apical lung tumors can compress neurovascular structures in the upper extremity and cause pain, numbness, and tingling in the ipsilateral arm.


Question: A 55-year-old male bodybuilder presents to the emergency department with weakness of his right arm. The patient states he has experienced these symptoms for a few weeks; however, today his hand felt so weak he dropped his cup of tea. The patient has a medical history of diabetes. He drinks 2-7 alcoholic drinks per day and has smoked 2 packs of cigarettes per day since he was 25. The patient uses anabolic steroids. He has lost 17 pounds since he last came to the emergency department 1 month ago. His temperature is 99.5°F (37.5°C), blood pressure is 177/108 mmHg, pulse is 90/min, respirations are 17/min, and oxygen saturation is 98% on room air. Physical exam reveals decreased sensation in the right arm and 2/5 strength in the right arm and 5/5 strength in in the left arm. The patient states that he is experiencing a dull aching and burning pain in his right arm during the exam. Symptoms are not changed with changes in head and neck position. Which of the following is the most likely diagnosis?

Answer: Apical lung tumor


Question: A 57-year-old man presents to the emergency department for shortness of breath. He was riding the train home from a business conference when his symptoms began. The patient has a medical history of obesity, diabetes, diabetic nephropathy, hypertension, and a 40-pack-year smoking history. His current medications include atorvastatin, lisinopril, insulin, metformin, and nicotine gum. His temperature is 99.5°F (37.5°C), blood pressure is 130/87 mmHg, pulse is 120/min, respirations are 15/min, and oxygen saturation is 93% on room air. An ECG is ordered as seen in Figure A. A chest radiograph is ordered as seen in Figure B. Laboratory values are ordered as seen below: Serum: Na+: 137 mEq/L Cl-: 105 mEq/L K+: 4.1 mEq/L HCO3-: 24 mEq/L BUN: 22 mg/dL Glucose: 129 mg/dL Creatinine: 1.2 mg/dL Ca2+: 10.1 mg/dL AST: 11 U/L ALT: 12 U/L On physical exam, the patient appears to be in distress. His cardiac exam is notable for tachycardia. Pulmonary exam reveals bilateral air movement without any wheezes or crackles. The patient's right lower extremity appears mildly inflamed, and palpation of the calf elicits pain. Which of the following is the most appropriate next step in management?

Answer: Heparin

Explanation:
This patient is presenting with a score of 7.5 on Wells criteria suggesting a diagnosis of pulmonary embolism. The most appropriate initial step in management is heparin administration.

Patients with suspected pulmonary embolism (PE) can be evaluated with Wells criteria which consists of: clinical signs and symptoms of DVT (3 points), PE is the most likely diagnosis (3 points), pulse > 100 (1.5 points), immobilization for 3 days, or surgery within 4 weeks (1.5 points), history of DVT or PE (1.5 points), hemoptysis (1 point), and malignancy (1 point). Scores higher than 3 suggest a high probability of PE. Patients will often present with shortness of breath, with ECG findings of sinus tachycardia, and a chest radiograph that is typically normal. With a high pre-test probability, the most important initial step in management is anticoagulation with heparin versus further diagnostic workup.

Doherty reviews the evidence regarding the diagnosis and treatment of pulmonary embolism. He discusses how clinical criteria such as Wells criteria can be helpful in assessing the likelihood of a PE. He recommends immediate treatment in patients who have a PE.

Figure/Illustration A is an ECG demonstrating sinus tachycardia with a P wave, a QRS complex, and a T wave during every beat (red circle). This is the most common ECG presentation in PE, though right heart strain can also be seen.

Figure B is a chest radiograph that is within normal limits without evidence of fluid in the dependent portions of the lung (red circles). This is the most common radiological presentation in PE.

Incorrect Answers:
Answer A: Aspirin would be the most appropriate initial step in the management of MI and can reduce mortality by up to 25% if administered promptly. PE is a more likely diagnosis in this patient given the ECG that only demonstrates sinus tachycardia.

Answer B: Cardiac troponins could be used to confirm the diagnosis of myocardial infarction (MI). In the presence of this patient's ECG (which does not demonstrate ST elevation), MI is a less likely diagnosis. Treatment would be with aspirin in patients who had an MI followed by emergent revascularization.

Answer C: A CT scan of the chest without contrast would not confirm the diagnosis in this patient; however, a CT angiogram would be the most accurate test. It is more important to begin treatment with heparin when there is a very high clinical suspicion of PE.

Answer E: A ventilation perfusion scan is the most accurate test for PE in a patient who cannot tolerate contrast. This test has a low specificity.

Bullet Summary:
The most appropriate initial step in the management of a pulmonary embolism in patients with a high pre-test probability is anticoagulation with heparin.


Question: A 39-year-old man presents to his doctor for a wellness checkup. He is concerned about a rash that does not seem to be improving. He was recently exposed to his grandfather who has vesicular lesions on his skin and is being treated. He has a family history of skin cancer, colon cancer, and ovarian cancer. The patient has a medical history of asthma and seasonal allergies. His temperature is 98.6°F (37.0°C), blood pressure is 137/98 mmHg, pulse is 90/min, respirations are 14/min, and oxygen saturation is 98% on room air. Physical exam reveals the finding in Figure A. Which of the following describes this patient's most likely diagnosis?

Answer: Benign capillary proliferation

Explanation:
This patient who presents with red raised papules is presenting with a cherry angioma. These lesions are composed of benign capillary proliferations.

Cherry angiomas present with cherry red macules/papules that occur secondary to benign capillary and venule proliferation. The lesions are entirely benign and are cosmetic. These lesions are common in middle-aged adults. As the patient ages, more lesions will appear. In the absence of symptoms, observation and reassurance can be used for conservative management. They can be removed surgically if the patient desires.

Nazer et al. study the risk factors associated with the development of cherry angioma. They found that the use of clopidogrel and tamsulosin is associated with these lesions. They recommend ruling out underlying conditions.

Figure/Illustration A demonstrates cherry red macules/papules classically seen in patients with cherry angioma.

Incorrect Answers:
Answer B: Edema of the epidermis describes eczema or atopic dermatitis. This disease would present with pruritic, erythematous, and vesicular lesions. Topical creams and hygiene can be used for symptomatic management of these lesions.

Answer C: Healthy dermatologic development misses the diagnosis of a cherry angioma, which although benign, is a more accurate diagnosis for this case.

Answer D: Malignant blood vessel proliferation does not describe a cherry angioma which is benign and purely cosmetic. An angiosarcoma usually occurs in deep tissues and requires surgical excision.

Answer E: Viral infection describes herpes simplex virus which would present with vesicular lesions and neurogenic pain. These patients can be treated with valacyclovir as well as gabapentin for neuropathic pain.

Bullet Summary:
Cherry angiomas are benign capillary proliferations that appear as cherry red macules/papules.


Question: An 84-year-old man presents to the physician with numbness and tingling in the right hand for the last 6 months. He reports these symptoms started intermittently in the middle finger after returning from a golfing trip but has progressed to being nearly constant. The thenar eminence, thumb, and other digits are spared. He reports no other symptoms. His medical problems include hypertension, hyperlipidemia, hypothyroidism, and chronic neck pain for which he takes amlodipine, hydrochlorothiazide, atorvastatin, levothyroxine, and duloxetine. Surgical history consists of posterior lumbar fusion and elective left total hip arthroplasty. He has a 90-pack-year smoking history and quit 10 years ago. The patient’s temperature is 99.6°F (37.6°C), blood pressure is 134/80 mmHg, pulse is 90/min, and respirations are 16/min. Physical exam reveals 4/5 strength in elbow extension and wrist flexion on the right. He has 5/5 strength in the remainder of the motor exam on the right upper extremity and on the left upper extremity. The triceps reflex is 1+ on the right compared to 2+ on the left. There is no spasticity. His neck pain, which radiates down his right arm, is reproduced with axial loading during neck extension with simultaneous rightward rotation and lateral bending. Which of the following is the most likely diagnosis in this patient?

Answer: Cervical spondylosis

Explanation:
This patient presents with chronic middle finger paresthesia, weakness in elbow extension and wrist flexion, and a diminished triceps reflex in the setting of a positive Spurling test (pain with axial loading during neck extension, rotation, and lateral bending towards the affected side), indicative of C7 cervical radiculopathy. Cervical spondylosis is a common cause of cervical radiculopathy in elderly patients with chronic neck pain, especially in patients with findings suggestive of degenerative joint diseases (history of lumbar fusion and hip arthroplasty).

Cervical spondylosis is caused by degeneration of the intervertebral disc with possible disc herniation and facet joints with osteophyte formation. These osteophytes and cervical disc herniation can cause compression of exiting nerve roots, leading to radiculopathy. Radicular symptoms depend on the nerve root affected. For example, C6 radiculopathy causes weakness in wrist extension and a decreased brachioradialis reflex while C7 radiculopathy causes weakness in elbow extension and wrist flexion with a decreased triceps reflex. Sensory symptoms may be present depending on the dermatome affected. The diagnosis is confirmed with MRI. Treatment consists of non-steroidal anti-inflammatory drugs (NSAIDs), muscle relaxants, and/or corticosteroids for pain. Surgical treatments for severe or refractory cases include anterior cervical discectomy and fusion.

Young outlines the diagnosis and management of cervical spondylotic myelopathy. The discusses its pathophysiology, including osteophyte formation and spinal cord dysfunction. They recommend considering decompression and fusion operations in selected patients.

Incorrect Answers:
Answer A: Amyotrophic lateral sclerosis (ALS) is a motor neuron disease of the brain and spinal cord that leads to upper and lower motor neuron signs. ALS presents with hyperreflexia (as opposed to hyporeflexia), spasticity, weakness, and fasciculations. Treatment includes riluzole (to improve survival) and symptomatic management.

Answer B: Carpal tunnel syndrome is caused by compression of the median nerve as it travels through the carpal tunnel at the wrist. While the thenar eminence is typically spared due to take-off of the palmar cutaneous branch proximal to the carpal tunnel, the thumb and index finger are also affected. This patient’s symptoms primarily involve the middle finger, which is more indicative of a radiculopathy. Treatment is activity modification, splinting, and ultimately, surgical decompression of the carpal tunnel if refractory.

Answer D: Syringomyelia is caused by a fluid-filled cavity (syrinx) within the spinal cord that leads to central cord syndrome, characterized by weakness that is greater in the upper extremities compared to lower extremities and loss of pain and temperature sensation in a cape-like distribution in the upper back and upper extremities. This patient’s sensory loss is unilateral and in a dermatomal distribution. Treatment of syringomyelia can include surgical decompression.

Answer E: Transverse myelitis is characterized by segmental inflammation of the spinal cord that would present with acute, bilateral flaccid paresis based on the level affected and sensory loss within a sensory level. Autonomic symptoms such as incontinence may also be present. This patient’s symptoms are unilateral and localizable to nerve root compression as opposed to the spinal cord.

Bullet Summary:
Cervical spondylosis is caused by degeneration of cervical discs and facet joints with osteophyte formation and can present with symptoms of cervical radiculopathy or myelopathy in elderly patients with chronic neck pain.


Question: A 55-year-old woman is brought to the emergency department by her husband with a 1 hour history of an unremitting headache. The headache started suddenly while she was eating dinner and she says it feels like the “worst headache of my life.” An emergent CT scan of the head without contrast confirms the diagnosis, and a CT angiogram identifies the source of bleeding. The patient undergoes surgical management of her condition. On hospital day 3, she is found to be disoriented to person, place, and time. She also develops nausea and vomiting. Her medical problems consist of heart failure for which she takes furosemide, spironolactone, and metoprolol, which were continued at admission. Her temperature is 99.6°F (37.6°C), blood pressure is 100/60 mmHg, pulse is 112/min, and respirations are 16/min. Physical examination shows poor skin turgor. Capillary refill time is 4 seconds. Serum laboratory results are shown below: Na+: 120 mEq/L Cl-: 92 mEq/L K+: 3.9 mEq/L HCO3-: 26 mEq/L BUN: 32 mg/dL Creatinine: 1.0 mg/dL Serum osmolality is 265 mEq/L and urine osmolality is 340 mEq/L. Urine sodium is 44 mEq/L. Which of the following is the most likely diagnosis?

Syndrome of inappropriate anti-diuretic hormone

Answer: Cerebral salt wasting


Question: A 51-year-old man presents for his annual wellness visit with his primary care physician. His wife has noticed a tremor while he is working on his car and knows that his father died of Parkinson disease. He says that the tremor is nothing to worry about and only occurs during a few activities such as pouring drinks, pointing the remote at the television, or fixing his car. The patient states his wife is just overreacting. His medical problems include hypertension, diabetes, and hyperlipidemia for which he takes lisinopril, metformin, and atorvastatin. He has 3-5 drinks of scotch per night before working on his car. On physical exam, the tremor is replicated during finger to nose testing. Romberg sign is negative. Cranial nerves II-XII are intact. The rest of the exam is benign. Which of the following is the most appropriate treatment for this patient's tremor?

Answer: Propranolol

Explanation:
This patient who presents with a tremor that only occurs during terminal activity and is likely improved by alcohol (hence why he drinks prior to working on the car) has benign essential tremor. This is best treated with propranolol.

Benign essential tremor is a type of rhythmic oscillatory movement that occurs with posturing and action. The pathophysiology of this disorder is unclear; however, it classically gets worse with actions that require terminal positioning of the extremities such as pouring a drink or pointing a television remote. The tremor improves with alcohol consumption so patients will often self-medicate with alcoholic drinks. There is a strong genetic component, with an autosomal dominant pattern of inheritance with incomplete penetrance. The best method of replicating the tremor is with the finger-nose-finger test because this requires the patient to perform a precise activity at a terminal distance. The diagnosis is made clinically. Treatment is with propranolol or primidone, which are both considered first-line agents although the latter has less evidence for its efficacy.

Paparella et al. studied the effects of propranolol on head and upper extremity movements in patients with benign essential tremors. They found that this medication has no effect on head movements but reduces the number of upper extremity tremors in these patients. They recommended that agents other than propranolol should be used for the treatment of head tremors in these patients.

Incorrect Answers:
Answer A: Alcoholics anonymous is the first-line treatment for patients with alcohol use disorder; however, the tremors that occur during alcohol withdrawal are not isolated to movements during terminal activities. Alcohol withdrawal also presents with other signs including restlessness, diaphoresis, and insomnia. More severe cases can present with hallucinations and seizures. The response of this patient's tremor to alcohol consumption is typical of patients with benign essential tremor.

Answer B: Aripiprazole and other atypical antipsychotic medications can be used in patients with Tourette syndrome; however, these patients will present with involuntary tics rather than a tremor that only occurs during a voluntary activity at the terminal range of motion. Moreover, for the diagnosis of Tourette syndrome, both motor and phonic tics must be present.

Answer C: Carbidopa can be used in the treatment of Parkinson disease; however, the tremor associated with this disease classically occurs at rest and is described in character as a "pill-rolling" tremor. The other features of Parkinson disease include bradykinesia or akinesia, rigidity, and postural instability.

Answer D: Phenobarbital can be used in the treatment of Huntington disease; however, the involuntary movements seen in this disease are classically choreiform rather than intention tremor. Huntington disease presents with chorea, psychiatric illness, and depression. There is commonly a strong genetic predisposition, as it is a trinucleotide repeat disorder that exhibits anticipation.

Bullet Summary:
Propranolol can be used in the treatment of patients with benign essential tremor, which presents with an action tremor that is alleviated by alcohol use.


Question: A 70-year-old woman is brought to the emergency department by ambulance. She was found on the floor of her apartment after her neighbor called 911. She is confused and is unable to provide any history, but complains of generalized pain. Her temperature is 99.2°F (37.3°C), blood pressure is 129/64 mmHg, pulse is 63/min, respirations are 13/min, and oxygen saturation is 99% on room air. Physical exam reveals, a confused, ill-appearing woman. Lungs are clear to auscultation bilaterally. An electrocardiogram is obtained as shown in Figure A. Dipstick urinalysis is notable for 4+ blood and dark colored urine. Which of the following is the most appropriate next step in management?

Answer: Calcium gluconate

Explanation:
This patient with confusion, dark urine, and peaked T waves on electrocardiogram in the setting of a prolonged time spent down likely has developed rhabdomyolysis with associated hyperkalemia. For patients with suspected hyperkalemia and electrocardiogram changes, the most appropriate next step in management is treatment with calcium gluconate

Rhabdomyolysis occurs when muscle cells lyse and release their intracellular contents. This can occur secondary to intense athletics, seizures, stimulant drug use, or a prolonged period of immobility. Lysis of muscle cells leads to release of potassium, myoglobin, purines, and other intracellular contents. Release of large amounts of myoglobin can result in renal impairment and myoglobinuria. On dipstick urinalysis, myoglobin causes a positive result for blood. Renal impairment further increases the risk for development of hyperkalemia. On ECG, hyperkalemia manifests with a "peaked" appearance of T waves, especially in the precordial leads. As hyperkalemia worsens, electrocardiogram changes progress to loss of P waves, QRS complex widening, and eventual sine wave rhythm. For patients with suspected hyperkalemia and characteristic changes noted on the electrocardiogram, the most appropriate immediate step in management is treatment with intravenous calcium gluconate. Calcium gluconate acts to stabilize cardiac myocyte membranes and prevent development of life-threatening arrhythmias.

Gupta et. al review rhabdomyolysis. They discuss the pathophysiology, clinical manifestations and diagnosis. They further detail complications that may arise such as hyperkalemia, and discuss respective management strategies.

Figure A demonstrates an electrocardiogram with features characteristic of hyperkalemia. Note the peaked appearance of the T waves in the precordial leads.

Incorrect Answers:
Answer A: Albuterol and IV fluid resuscitation may eventually be appropriate. Albuterol (a beta agonist) will act to shift potassium to the intracellular compartment. This patient's electrocardiogram changes warrant immediate treatment with calcium gluconate in order to stabilize cardiac myocyte membranes.

Answer C: Insulin, glucose, and IV fluid resuscitation are indicated in this patient. Insulin acts to shift potassium to the intracellular compartment, and fluid resuscitation is warranted for the patient's likely renal impairment. Calcium gluconate is the more immediate priority to prevent development of arrhythmia.

Answer D: IV fluid resuscitation is indicated for this patient with likely renal impairment. However, calcium gluconate is the more immediate priority to address this patient's hyperkalemia and prevent development of arrhythmia.

Answer E: Sodium polystyrene is an oral potassium binder that increases GI excretion of potassium. It may be appropriate to treat mild hyperkalemia in some patients. It takes a prolonged amount of time to have any significant effect.

Bullet Summary:
For patients with suspected hyperkalemia and characteristic changes noted on ECG, the most appropriate immediate step in management is treatment with intravenous calcium gluconate.


Question: A 72-year-old man presents to his primary care physician for a general checkup. The patient works as a farmer and has no concerns about his health. He has a medical history of hypertension and obesity. His current medications include lisinopril and metoprolol. His temperature is 99.5°F (37.5°C), blood pressure is 177/108 mmHg, pulse is 90/min, respirations are 17/min, and oxygen saturation is 98% on room air. Physical exam is notable for a murmur after S2 over the left sternal border. The patient demonstrates a stable gait and 5/5 strength in his upper and lower extremities. Which of the following is another possible finding in this patient?

Murmur that radiates to the carotids during systole

Answer: Femoral artery murmur

Explanation:
This patient is presenting with aortic regurgitation which could be associated with Duroziez sign (femoral artery murmur).

Aortic regurgitation occurs when the aortic valve closes improperly resulting in retrograde flow during diastole. This is auscultated as a diastolic murmur heard best over the left upper sternal border and the left lower sternal border. This murmur typically occurs in elderly patients and the retrograde flow through the aorta cause a number of physical exam findings. These include a wide pulse pressure, fingernail pulsations, head bobbing, and femoral artery murmur. Treatment is with surgical valve replacement.

Sapira reviews the evidence regarding the physical exam findings in aortic regurgitation. He discusses how Duroziez sign can often be seen in patients with this disease. He recommends using these signs to properly identify patients.

Incorrect Answers:
Answer A: An audible click heard at the cardiac apex describes mitral valve prolapse which typically is asymptomatic and presents in younger women. Treatment is with surgical valve replacement in symptomatic patients.

Answer C: A murmur that radiates to the carotids during systole describes aortic stenosis which is possible in this patient except for the fact that his murmur is diastolic. Treatment is with valvuloplasty or with surgical valve replacement.

Answer D: A rumbling heard at the cardiac apex describes mitral valve stenosis which presents with a diastolic murmur best heard at the cardiac apex. Treatment is with valvuloplasty or with surgical valve replacement.

Answer E: A wedge pressure lower than expected would be seen in tricuspid regurgitation. In tricuspid stenosis, less blood flows to the lungs and thus the left heart, resulting in a low wedge pressure. Treatment is with identification of the underlying cause and valve replacement.

Bullet Summary:
Aortic regurgitation is associated with a wide pulse pressure, fingernail pulsations, head bobbing, and a femoral artery murmur.


Question: A 39-year-old man presents to his doctor for a wellness checkup. He is concerned about a rash that does not seem to be improving. He was recently exposed to his grandfather who has vesicular lesions on his skin and is being treated. He has a family history of skin cancer, colon cancer, and ovarian cancer. The patient has a medical history of asthma and seasonal allergies. His temperature is 98.6°F (37.0°C), blood pressure is 137/98 mmHg, pulse is 90/min, respirations are 14/min, and oxygen saturation is 98% on room air. Physical exam reveals the finding in Figure A. Which of the following describes this patient's most likely diagnosis?

Answer: Benign capillary proliferation


Question: A 15-year-old girl is brought to the clinic because her mother is worried the patient has not yet had her period. The patient’s older sister had her first period at age 14. The mother had her first period at age 13. The patient reports she is doing well in school and is on the varsity basketball team. Her medical history is significant for asthma and atopic dermatitis. Her medications include albuterol and topical triamcinolone. Her temperature is 98°F (36.7°C), blood pressure is 111/72 mmHg, pulse is 65/min, and respirations are 14/min with an oxygen saturation of 99% on room air. Her body mass index (BMI) is 19 kg/m^2. Physical exam shows absent breast development and external genitalia at Tanner stage 1. Serum follicle-stimulating hormone (FSH) level is measured to be 38 mIU/mL. Which of the following is the most appropriate next diagnostic step?

Gonadotrophin-releasing hormone stimulation test

Answer: Karotype

Explanation:
The patient is presenting with primary amenorrhea and an increased follicle-stimulating hormone (FSH) level, suggesting a gonadal abnormality and making karyotyping the most appropriate next step in management.

Primary amenorrhea can be diagnosed if a patient has normal secondary sex characteristics but no menarche by age 16, or if she has no secondary sex characteristics and no menarche as early as age 14. Primary amenorrhea is caused by either hypothalamic/pituitary (central) or gonadal (peripheral) abnormalities. Increased FSH indicates a peripheral cause or hypergonadotropic hypogonadism. Karyotyping would be the most appropriate next diagnostic step because these disorders can include Turner syndrome and androgen insensitivity syndrome.

Gravholt et al. review the evidence regarding the diagnosis and treatment of Turner syndrome. They discuss how this disease presents with hypergonadotropic hypogonadism. They recommend growth hormone therapy and hormone replacement therapy in these patients.

Incorrect Answers:
Answer A: CYP17 gene work-up should be done in patients with primary amenorrhea, an absence of secondary sex characteristics, elevated FSH, and hypertension. Alterations in the CYP17 gene can cause congenital adrenal hyperplasia due to 17-hydroxylase deficiency. The resulting excess of deoxycorticosterone is associated with hypertension and hypokalemia. Treatment is with hormone repletion therapy.

Answer B: Estrogen levels would be low in this patient as evidenced by her absence of breast development. Therefore, measuring estrogen levels would provide no additional diagnostic information. Estrogen levels may be useful in cases of peripheral gonadotropin resistance but these are rare.

Answer C: Gonadotropin-releasing hormone (GnRH) stimulation test would be the next diagnostic step if FSH were decreased. A decrease in FSH indicates a central cause or hypogonadotropic hypogonadism. A GnRH stimulation test is used to assess whether the central abnormality is due to the hypothalamus or the pituitary.

Answer E: Luteinizing hormone (LH) levels with a repeat FSH level may be helpful if FSH is low or normal. Low or normal FSH levels indicate hypogonadotropic hypogonadism as caused by hypothalamic-pituitary axis abnormalities. Cases of high FSH represent a different diagnostic entity as adequate gonadotropins are produced.

Bullet Summary:
In a patient with primary amenorrhea and an increased FSH, the next step in management is karyotyping.


Question: A 37-year-old machinist presents to his primary care physician with eye problems. He has felt a mass in his eye that has persisted for the past month. The patient has a medical history of blepharitis treated with eye cleansing and squamous cell carcinoma of the skin treated with Mohs surgery. His temperature is 99.5°F (37.5°C), blood pressure is 157/102 mmHg, pulse is 90/min, respirations are 17/min, and oxygen saturation is 98% on room air. Physical exam is notable for a firm and rubbery nodule palpable inside the patient's left eyelid. Physical exam does not elicit any pain. Which of the following is the most likely diagnosis?

Answer: Chalazion

Explanation:
This patient presenting with a painless firm and rubbery nodule has symptoms that are suggestive of a chalazion.

Chalazion presents with a hard and painless eyelid nodule. This pathology occurs secondary to granulomatous inflammation of the Meibomian gland. The lesion can be treated with simple excision; however, recurrent lesions are concerning for Meibomian cell carcinoma. The most important differential diagnosis to consider in these patients is a hordeolum which presents with a firm and painful lid nodule (in contrast to painless). Treatment is with warm compresses followed by incision and curettage in refractory cases.

Li et al. review the evidence regarding the diagnosis and treatment of chalazion. They discuss how gland loss is a possible sequelae from this disorder. They recommend using warm compresses for symptomatic relief.

Incorrect Answers:
Answer B: Foreign body is a possible diagnosis given this patient's occupation as a machinist; however, this would typically present with pain over the patient's cornea with a sudden onset of symptoms. Treatment is with removal of the foreign body.

Answer C: Hordeolum presents with a hard and painful lid nodule in contrast to a hard and painless lid nodule. Treatment is with warm compresses and possible debridement in refractory cases.

Answer D: Ingrown eyelash follicle could present with a firm lid nodule; however, it would be located near the margin of the eyelid and would likely be inflamed and tender. Treatment is with warm compresses and possible debridement in refractory cases.

Answer E: Meibomian cell carcinoma is a possible diagnosis but is epidemiologically less common than a chalazion. This diagnosis would be more likely if the lesion was recurrent despite excision. Treatment is with wide excision of the lesion.

Bullet Summary:
Chalazion presents with a firm and painless eyelid nodule.


Question: A 59-year-old man presents to his primary care physician for fatigue. In general, he has been in good health; however, he recently has experienced weight loss, abdominal pain, and general fatigue. He has a medical history of anxiety, diabetes, a fracture of his foot sustained when he tripped, and a recent cold that caused him to miss work for 1 week. His current medications include metformin, insulin, buspirone, vitamin D, calcium, and sodium docusate. His temperature is 99.5°F (37.5°C), blood pressure is 150/100 mmHg, pulse is 90/min, respirations are 18/min, and oxygen saturation is 98% on room air. Physical exam reveals a calm gentleman. A mild systolic murmur is heard in the left upper sternal region. The rest of the physical exam is within normal limits. Laboratory values are ordered as seen below. Hemoglobin: 12 g/dL Hematocrit: 36% Leukocyte count: 66,500/mm^3 with normal differential Platelet count: 177,000/mm^3 Leukocyte alkaline phosphatase: elevated Serum: Na+: 139 mEq/L Cl-: 100 mEq/L K+: 4.3 mEq/L BUN: 20 mg/dL Glucose: 120 mg/dL Creatinine: 1.1 mg/dL Ca2+: 10.9 mEq/L AST: 12 U/L ALT: 10 U/L Which of the following is the most likely diagnosis?

Answer: Leukemoid reaction

Explanation:
This patient is presenting with leukocytosis and an elevated leukocyte alkaline phosphatase suggestive of a leukemoid reaction.

A leukemoid reaction typically presents with a drastically elevated leukocyte count (typically > 50,000/mm^3) in the setting of an elevated leukocyte alkaline phosphatase score (LAP). This reaction typically occurs after a major infection and is an immunologic response to the pathogen that caused the illness. In contrast, chronic myeloid leukemia presents with a similar elevation in leukocytes but a low LAP score in addition to symptoms of general malaise, fatigue, and weight loss. The LAP score is the critical differentiating factor when comparing these 2 pathologies. Treatment for a leukemoid reaction is by addressing the underlying pathology.

Portich and Faulhaber review the evidence regarding the diagnosis of leukemoid reaction. They discuss how the most common cause is infection. They recommend considering paraneoplastic syndromes in patients without evidence of infection.

Incorrect Answers:
Answer A: Acute lymphoblastic lymphoma presents in a pediatric patient with pallor, fatigue, easy bruising, fever, bone pain, hepatomegaly, and splenomegaly. Treatment is with combination chemotherapy.

Answer B: Chronic lymphocytic leukemia can present similarly to a leukemoid reaction with non-specific systemic symptoms and lymphadenopathy but is a less likely diagnosis in this patient given his age and LAP score. Treatment is with ibrutinib and rituximab as well as other agents.

Answer C: Chronic myeloid leukemia presents with systemic symptoms, fatigue, malaise, weight loss, and abdominal pain with an elevated leukocyte count (typically > 50,000/mm^3) but a depressed LAP score. Treatment is with tyrosine kinase inhibitors.

Answer E: Multiple myeloma presents with systemic symptoms, weight loss, pathologic fractures, and hypercalcemia. It is not associated with an elevated leukocyte score and an elevated LAP score. Treatment is with steroids and chemotherapy.

Bullet Summary:
Both a leukemoid reaction and chronic myeloid leukemia present with an elevated leukocyte count (> 50,000/mm^3), but an elevated leukocyte alkaline phosphatase score is suggestive of a leukemoid reaction.


Question: A 67-year-old man presents to the emergency room with difficulty speaking for the past 1 hour. He was having dinner at home with his wife when he suddenly noticed he had difficulty eating and speaking. He also noticed a new-onset weakness on his left side. His medical history is significant for type 2 diabetes mellitus, hypertension, and hyperlipidemia. His current medications include metformin, atorvastatin, and lisinopril. His temperature is 98.6°F (37°C), blood pressure is 130/80 mmHg, pulse is 70/min, and respirations are 15/min. On examination, strength is 5/5 in the right upper and lower extremities and 3/5 in the left upper and lower extremities. On cranial nerve examination, his tongue deviates to the right side. There is also decreased sensation to light touch and vibration on the left side of his body. Which of the following arteries is most likely involved in this patient’s presentation?

Answer: Anterior spinal artery

Explanation:
This patient with hypertension, diabetes, hyperlipidemia, deviation of the tongue to the right, left-sided hemiparesis, and decreased sensation to light touch and vibration on the left side of his body most likely has a stroke of the right medial medulla. The medial medulla is supplied by paramedian branches of the vertebral arteries and the anterior spinal artery.

Medial medullary syndrome (Dejerine syndrome) is usually caused by atherosclerotic occlusion of paramedian branches of the anterior spinal artery, vertebral arteries, or basilar artery which supply the medial medulla. Medial medullary structures include the lateral corticospinal tract, the medial lemniscus, and the hypoglossal nerve. Lesions to the lateral corticospinal tract lead to contralateral paresis of the upper and lower extremities. Lesions to the medial lemniscus lead to decreased vibration, proprioception, and light touch on the contralateral body. Ipsilateral hypoglossal nerve dysfunction leads to ipsilateral loss of function of the intrinsic and extrinsic muscles of the tongue including the genioglossus muscle, which protrudes the tongue forward from the root and is unopposed on the contralateral side. This pushes the tongue towards the side of the lesion, leading to ipsilateral tongue deviation. Treatment includes reperfusion via thrombolytics if the patient presents within 4.5 hours of the time last known well.

Kim and Han present clinical findings, radiographic findings, angiographic data, and long-term outcomes from a case series of 86 patients with medial medullary infarction. The authors found that old age and severe motor dysfunction at admission were predictive factors portending poor prognosis. The authors recommend close follow-up of these patients for the development of central post-stroke pain.

Incorrect Answers:
Answer A: Anterior inferior cerebellar artery infarction leads to a lesion of the lateral pons, with damage to the facial nucleus, vestibular nuclei, spinothalamic tract, spinal trigeminal nucleus, sympathetic fibers, labyrinthine artery, and middle and inferior cerebellar peduncles. This presents with complete facial hemiparesis, vomiting, decreased pain and temperature sensation on the contralateral body and ipsilateral face, ipsilateral Horner syndrome, ipsilateral ataxia and dysmetria, and ipsilateral sensorineural deafness and vertigo.

Answer C: Lenticulostriate branches of the middle cerebral artery supply the internal capsule. Strokes of the posterior limb of the internal capsule lead to contralateral hemiparesis. The findings of ipsilateral tongue deviation and sensory changes are not consistent with a lesion to the internal capsule.

Answer D: Pontine perforators of the basilar artery supply the medial pons. Strokes of the medial pons lead to quadriplegia and loss of facial, mouth, and tongue movements with preserved sensorium. This patient’s findings of hemiparesis, ipsilateral tongue deviation, and changes in sensorium are more suggestive of a lesion to the medial medulla, not the medial pons.

Answer E: Posterior inferior cerebellar artery infarction leads to a stroke of the lateral medulla (Wallenberg syndrome). This leads to lesions to the nucleus ambiguus, vestibular nuclei, lateral spinothalamic tract, spinal trigeminal nucleus, sympathetic fibers, and inferior cerebellar peduncle. Clinically this presents with dysphagia, hoarseness, decreased gag reflex, vomiting, vertigo, decreased pain and temperature sensation from the contralateral body and ipsilateral face, ipsilateral Horner syndrome, and ipsilateral ataxia.

Bullet Summary:
Occlusion of the anterior spinal artery can lead to medial medullary syndrome, which presents with ipsilateral deviation of the tongue, contralateral paresis of the upper and lower extremities, and contralateral loss of light touch and vibration sensation.


Question: A 15-year-old boy presents to his pediatrician after an appendectomy 1 week ago. The patient denies any abdominal pain, fevers, chills, nausea, vomiting, diarrhea, or constipation. He eats solids and drinks liquids without difficulty. He is back to playing basketball for his school team without any difficulty. His urine appears more amber than usual but he suspects dehydration. His temperature is 98.6°F (37°C), blood pressure is 110/70 mmHg, pulse is 76/min, and respirations are 15/min. His physical exam is unremarkable. The laparoscopic incision sites are all clean without erythema. The pediatrician orders a urinalysis, which is notable for the following. Urine: Epithelial cells: Scant Glucose: Negative Protein: 3+ WBC: 3/hpf Bacteria: None Leukocyte esterase: Negative Nitrites: Negative The patient is told to return in 3 days for a follow-up appointment; however, his urinalysis at that time is similar. Which of the following is the most appropriate next step in management?

CT scan abdomen and pelvis with contrast

Urine dipstick in the morning and in the afternoon

Answer: Urine dipstick in the morning and in the afternoon

Explanation:
This patient is found to have proteinuria on urinalysis in the absence of clinical symptoms or signs of nephrotic syndrome. Given the likely diagnosis of transient proteinuria, the most appropriate next step is to repeat the urine dipstick in the morning and in the afternoon.

Transient proteinuria can be due to febrile illnesses, seizures, strenuous exercise, emotional stress, serious illnesses like heart failure, and abdominal surgery. A detailed workup is not needed if the clinical story is clear, but an orthostatic test can be completed. One way to do this is to assess the urine dipstick in the morning and in the afternoon. Another way requires the patient to collect urine at multiple times throughout the day. A diagnosis is confirmed if the morning sample is protein-free but the evening sample contains protein. In general, pediatric patients with orthostatic proteinuria should have under 1 gram of protein in a full 24 hours. Treatment is with reassurance because this condition usually resolves by itself.

Ingold and Bhatt review the evidence regarding the diagnosis and treatment of orthostatic proteinuria in patients. They discuss how this condition is benign and typically occurs in adolescents. They recommend reassurance and supportive treatment.

Incorrect Answers:
Answer A: A CT scan of the abdomen and pelvis with contrast could assess for any anatomic obstruction and a possible post-renal cause of kidney dysfunction. It would be more prudent to obtain basic labs and a timed urinalysis before exposing a pediatric patient to radiation.

Answer B: Renal biopsy is indicated if the patient's clinical presentation is concerning for a glomerular or tubulointerstitial etiology for proteinuria. Patients will have edema, hematuria, or dysuria.

Answer C: Repeat urinalysis will not change the presence of proteinuria. Generally, a patient who has proteinuria should have a repeat urinalysis performed to rule out transient proteinuria. If the repeat urinalysis demonstrates proteinuria (as in this patient), then the diagnosis is unlikely to be transient proteinuria, and further workup is needed.

Answer E: Urine electrolytes and creatinine will assess the kidney's ability to concentrate urine and assess the etiology of acute kidney injury. Patients will present with oliguria or anuria.

Bullet Summary:
Consistent proteinuria in a child should by evaluated by performing a urinalysis in the morning and in the afternoon to see if proteinuria comes on toward the end of the day.


Question: A 37-year-old man presents to the emergency department for a persistent fever. The patient has felt unwell for the past week and has felt subjectively febrile. The patient has a medical history of a suicide attempt and alcohol abuse. He is not currently taking any medications. The patient admits to using heroin and cocaine and drinking 5-8 alcoholic drinks per day. His temperature is 103°F (39.4°C), blood pressure is 92/59 mmHg, pulse is 110/min, respirations are 20/min, and oxygen saturation is 96% on room air. Cardiopulmonary exam is notable for a systolic murmur heard best along the left sternal border. Dermatologic exam reveals scarring in the antecubital fossa. IV fluids are administered and the blood pressure is subsequently 120/70 mmHg. Which of the following is the most appropriate next step in management for the most likely underlying diagnosis?

Answer: Blood cultures

Explanation:
This patient is presenting with fever and a systolic murmur suggestive of bacterial endocarditis. The most appropriate initial step in management is to draw blood cultures.

Bacterial endocarditis presents with fever, systemic symptoms (aches, myalgias, and fatigue), and a new murmur typically in a patient with intravenous drug use. These patients introduce bacteria intravenously which then flows to the right side of the heart and can cause right-sided endocarditis. The most appropriate initial step in management is to draw blood cultures. Once blood cultures have been drawn, broad-spectrum antibiotics can be started (vancomycin and gentamicin), and an ultrasound can be performed to further support the diagnosis (or rule out vegetations) and plan operative interventions if necessary.

Wang et al. review the evidence regarding the diagnosis and treatment of infectious endocarditis. They discuss how echocardiogram and blood cultures are the mainstay of diagnosis. They recommend broad spectrum antibiotics.

Incorrect Answers:
Answer B: A chest radiograph may be performed in the workup for bacterial endocarditis; however, it is not the most appropriate initial step in management and is neither sensitive nor specific.

Answer C: A CT scan would not be a very helpful confirmatory test in the diagnosis of bacterial endocarditis. A better confirmatory test would be an ultrasound. It may workup alternative causes of fever such as pneumonia.

Answer D: Ultrasound (echocardiography) would be the imaging test of choice for bacterial endocarditis. It would be performed after blood cultures have been drawn and antibiotics had been started.

Answer E: Vancomycin and gentamicin are the broad-spectrum antibiotics of choice for bacterial endocarditis. They would be started after blood cultures have been drawn and reduce mortality when given early in sepsis.

Bullet Summary:
The most appropriate initial step in the management of bacterial endocarditis after initial stabilization is to draw blood cultures.


Question: A 27-year-old man presents to his primary care physician for a checkup. He has no health concerns and has not seen a physician in years. The patient has a medical history of depression treated with fluoxetine and lithium. His temperature is 99.5°F (37.5°C), blood pressure is 122/78 mmHg, pulse is 90/min, respirations are 13/min, and oxygen saturation is 98% on room air. Physical exam is notable for the finding in Figure A. Which of the following represents the most likely risk factor for this patient's presenting condition?

Answer: Alcohol consumption

Explanation:
This patient is presenting with adherent white plaques on the inside of the cheek consistent with oral leukoplakia. Alcohol consumption is a risk factor for this disease.

Oral leukoplakia presents with a white patch/plaque that occurs over the oral mucosa that is adherent and non-scrapable. Risk factors for this condition include the risk factors for squamous cell carcinoma such as consumption of alcohol and smoking. Though the cause of this lesion is largely idiopathic, any irritating substance can induce it. Other potential risk factors include candidiasis, vitamin deficiency, endocrine disturbances, and viral infections. A diagnosis can be made using a biopsy showing the degree of dysplasia. Treatment is with smoking and alcohol cessation as well as surgical removal for suspicious lesions.

Mohammed and Fairozekhan review the evidence regarding the diagnosis and risk factors for leukoplakia. They discuss how this disease is associated with smoking and alcohol use. They recommend screening patients for these modifiable risk factors.

Figure/Illustration A is a clinical photograph demonstrating adherent white plaques on the inside of the cheek (red circle). These findings are consistent with oral leukoplakia.

Incorrect Answers:
Answer B: Antibiotic use is a risk factor for candidiasis; however, this patient is not presenting with symptoms of candidiasis which is itself a risk factor for oral leukoplakia. Candidiasis presents with opaque white lesions that can be scraped off.

Answer C: Intravenous drug use does make this patient riskier overall for many conditions; however, alcohol is a more direct risk factor for oral leukoplakia. Immunodeficiency conditions can cause widespread fungal and viral infections on the mucosal surfaces.

Answer D: Poor dental hygiene may be found more often in patients with oral leukoplakia; however, it is not itself a direct cause.

Answer E: Sexual intercourse would predispose this patient to infections and viruses (such as Epstein-Barr virus); however, it is a less likely risk factor than is alcohol consumption or smoking. These infections tend to present with ulcers more commonly than leukoplakia.

Bullet Summary:
Risk factors for oral leukoplakia and squamous cell carcinoma include alcohol consumption and smoking.


Question: A 32-year-old man presents to the emergency department for evaluation of headache. His symptoms started last night and have persisted. He occasionally has migraine headaches, but he has not had a headache like this in the past. He reports associated nausea, vomiting, fevers, and neck pain. He has a medical history of asthma. His temperature is 100.4°F (38.0°C), blood pressure is 110/60 mmHg, pulse is 95/min, respirations are 17/min, and oxygen saturation is 98% on room air. On physical exam, he appears uncomfortable. Neurologic exam reveals no focal deficits. There is pain with passive neck flexion. No edema or rashes are noted. Lungs are clear to auscultation bilaterally. Lumbar puncture is performed and CSF results are obtained as shown below. Cerebrospinal fluid (CSF): Cell count: 175/mm^3 RBCs: 0/mm^3 Cl-: 119 mEq/L Glucose: 49 mg/dL Pressure: 150 mmH2O Total protein: 55 mg/dL Based on these results, which of the following is the most appropriate treatment regimen for this patient?

Answer: Supportive care and monitoring

Explanation:
This patient with headache, fever, and neck stiffness has a presentation and CSF studies consistent with a diagnosis of viral or aseptic meningitis. Supportive care is the most appropriate management strategy for patients with viral meningitis.

Aseptic (viral) meningitis presents similarly to bacterial meningitis with neck stiffness, photophobia, fever, malaise, and flu-like symptoms. Patients should be worked up and treated as if they have bacterial meningitis until proven otherwise. CSF findings in aseptic meningitis show an elevated cell count (though typically < 300/mm^3 in contrast to bacterial meningitis), a normal or elevated protein, and a normal glucose. CSF should be sent for Gram stain and culture to confirm the diagnosis and rule out bacterial meningitis. Once the diagnosis has been confirmed, management of viral meningitis consists of supportive care and monitoring for complications such as seizures, cerebral edema, or SIADH.

Kohil et. al review viral meningitis. They discuss the pathophysiology, clinical manifestation and diagnosis. They recommend that most patients with viral meningitis be treated with supportive care.

Incorrect Answers:
Answer A: Acyclovir would be appropriate for suspected HSV or varicella encephalitis or meningitis. This patient with no RBCs in the CSF and no changes in mental status is not likely to have infection with HSV or varicella.

Answer B: Amphotericin and 5-flucytosine followed by long-term fluconazole is the appropriate management of cryptococcal meningitis. Cryptococcal meningitis presents similarly to bacterial and viral meningitis, almost exclusively in immunocompromised patients.

Answer C: Ceftriaxone and vancomycin would be appropriate if bacterial meningitis was suspected. Steroids are generally added if a bacterial source is likely. However, this patient has a presentation that is less concerning for bacterial meningitis, and CSF studies that are more consistent with aseptic meningitis.

Answer D: Ceftriaxone, vancomycin and steroids are an appropriate initial regimen for bacterial meningitis. Dexamethasone reduces inflammatory injury while patients are being treated with antibiotics.

Bullet Summary:
Viral or aseptic meningitis is managed with supportive care and monitoring.


Question: A 23-year-old woman presents to her psychiatrist concerned about her mood. She has felt tired and unwilling to engage in any activities lately. She states that her limbs feel heavy all the time and that completing any activity takes tremendous effort. She no longer finds any happiness in activities that she previously enjoyed. She struggles to sleep and at times can't sleep for several days. The patient is started on appropriate first-line therapy and sent home. She returns 1 week later stating that her symptoms have not improved. She is requesting help as her performance at work and school is suffering. Her temperature is 99.5°F (37.5°C), blood pressure is 115/72 mmHg, pulse is 60/min, respirations are 13/min, and oxygen saturation is 98% on room air. Which of the following is the most appropriate next step in management?

Answer: Continue current therapy

Explanation:
This patient is presenting with depression and should be treated with a selective serotonin reuptake inhibitor (SSRI) for at least 4 weeks. Patients who have tried the therapy for a shorter duration of time may not yet have experienced the benefit of the medication.

Depression presents with SIGE CAPS (Sleeplessness, Interest loss, Guilt, Energy decreased, Concentration abnormalities, Appetite changes, Psychomotor retardation, and Suicidal ideation). The most appropriate initial step in management is to treat the patient with an SSRI for at least 4 weeks since SSRI's take several weeks to reach their potential. If the treatment has failed after 4 weeks of use, altering the patient's medications could be appropriate. Treatment and side effects should be monitored by a physician.

Kato et al. review the evidence regarding the treatment of depression with SSRI medications. They discuss how medications should be used for at least 4 weeks to determine treatment response. They recommend not allowing patients to switch between drug classes too early.

Incorrect Answers:
Answer A: Adding lithium to the treatment regimen could be an appropriate treatment if this patient had failed to respond to therapy after 4 weeks of using the drug. Lithium is an augmenting agent that could potentiate the effect of an SSRI.

Answer B: Changing the treatment to duloxetine would be inappropriate as this patient has not taken the first-line SSRI for at least 4 weeks. Patients should try a full treatment course in order to determine if they may derive some benefit.

Answer C: Changing the treatment to lithium would be appropriate if this patient's diagnosis was bipolar disorder, which would present with episodes of depression and mania. Altered sleep alone does not indicate mania.

Answer E: Electroconvulsive therapy is the most effective treatment for depression; however, it is typically a last-line treatment. This therapy can be useful in refractory cases.

Bullet Summary:
SSRI medications are the most appropriate first-line agent for depression and should be tried for at least 4 weeks before changing therapy.


Question: A 23-year-old man presents to the emergency department for altered mental status after a finishing a marathon. He has a medical history of obesity and anxiety and is not currently taking any medications. His temperature is 104°F (40°C), blood pressure is 147/88 mmHg, pulse is 200/min, respirations are 33/min, and oxygen saturation is 99% on room air. Physical exam reveals dry mucous membranes, hot flushed skin, and inappropriate responses to the physician's questions. Laboratory values are ordered as seen below. Hemoglobin: 15 g/dL Hematocrit: 44% Leukocyte count: 8,500/mm^3 with normal differential Platelet count: 199,000/mm^3 Serum: Na+: 165 mEq/L Cl-: 110 mEq/L K+: 4.0 mEq/L HCO3-: 20 mEq/L BUN: 30 mg/dL Glucose: 133 mg/dL Creatinine: 1.5 mg/dL Ca2+: 10.2 mg/dL AST: 12 U/L ALT: 10 U/L Which of the following is the most appropriate next step in management?

Answer: Lactated ringer

Explanation:
This patient is presenting with hypernatremia and heat stroke for which the most appropriate next step in management is the administration of lactated ringer solution.

Heat stroke presents with hot/flushed skin, fever, altered mental status, and hypernatremia secondary to loss of free water. Patients should immediately be cooled with external measures and started on fluids. Minor cases where the patient is cognitively intact can be treated with oral replacement with an electrolyte balanced solution (though this would be heat exhaustion and not heat stroke). Patients with altered mental status should be started on normal saline or lactated ringer, and sodium levels should be corrected slowly. Rapid correction of serum sodium or administration of hypotonic fluids can cause cerebral edema and seizures; however, this is more common in hypernatremia that has persisted for days as it has led to cerebral adaptations.

Tinawi reviewed the evidence regarding the use of intravenous fluids in the hospital setting. He discusses how a large volume of normal saline can result in hypernatremia and hyperchloremia. He recommends considering the risks and benefits of colloid versus crystalloid usage.

Incorrect Answers:
Answers 1-3: 50% normal saline 50% dextrose, dextrose solution, and hypotonic saline are hypotonic solutions and would treat the hypernatremia too rapidly predisposing the patient to seizures.

Answer E: Normal saline would be a reasonable option for this patient; however, it is less desirable given that this patient is suffering from hypernatremia, hyperchloremia, and a metabolic acidosis which could be worsened by normal saline given the large sodium and chloride load of this solution.

Bullet Summary:
Hypernatremia and dehydration should be treated with lactated ringer and sodium levels should be corrected no more rapidly than 1 mEq/L/hour.


Question: A 70-year-old woman is brought to the emergency department by ambulance. She was found on the floor of her apartment after her neighbor called 911. She is confused and is unable to provide any history, but complains of generalized pain. Her temperature is 99.2°F (37.3°C), blood pressure is 129/64 mmHg, pulse is 63/min, respirations are 13/min, and oxygen saturation is 99% on room air. Physical exam reveals, a confused, ill-appearing woman. Lungs are clear to auscultation bilaterally. An electrocardiogram is obtained as shown in Figure A. Dipstick urinalysis is notable for 4+ blood and dark colored urine. Which of the following is the most appropriate next step in management?

Answer: Calcium gluconate


Question: A 51-year-old man presents to his primary care provider for intermittent shaking of his hands. For the last several years he has noticed this "shaking" when he brushes his teeth and prepares a cup of coffee in the morning. The shaking then gradually improves over the course of the day. His medical history is otherwise notable for hypertension and hyperlipidemia. His only home medication is pravastatin. The patient smokes half a pack per day of cigarettes and drinks 2-3 beers throughout the day. His family history is significant for Parkinson disease in his father. On physical exam, his temperature is 98.6°F (37.0°C), blood pressure is 159/84, pulse is 74/min, and respirations are 12/min. He has a high-frequency bilateral hand tremor elicited on finger-to-nose testing. His neurological exam is otherwise unremarkable. Which of the following medications should this patient be started on?

Answer: Propranolol

Explanation:
This patient presents with a high frequency bilateral action tremor, which suggests a diagnosis of benign essential tremor. In light of his concomitant hypertension, the patient should be started on propranolol.

Benign essential tremor usually presents as a bilateral tremor of the hands that is observed during fine motor movements. Patients present with worsening tremors with posturing and with voluntary movement and improve with alcohol and rest. First-line treatment includes propranolol and primidone, with propranolol being preferred for patients with hypertension or vascular risk factors. Refractory cases can be treated with deep brain stimulation which is often a last-line intervention.

Shanker reviewed the diagnosis and treatment of patients with essential tremors. She discusses how this disease presents with an action tremor that lasts for at least 3 years. She recommends treatment with propranolol or primidone.

Incorrect Answers:
Answer A: Alprazolam is sometimes used as second-line therapy for essential tremor refractory to propranolol and primidone but would not be used as initial therapy in this patient. Benzodiazepines can be used in patients with panic disorders.

Answer B: Primidone is a barbiturate that is another first-line treatment for essential tremor. For this patient, propranolol would be preferred to also treat this patient’s underlying hypertension. Primidone can be used in patients without other underlying comorbidities.

Answer D: Topiramate is an antiepileptic that may be used as a second-line treatment option for essential tremor. It would not be used as initial drug therapy. Topiramate can be used in the treatment of patients with partial seizures that present with motor symptoms.

Answer E: Trihexyphenidyl is an anticholinergic medication that is used to treat early Parkinson disease in which tremor is the predominant symptom. Despite this patient’s family history of Parkinson disease, the tremor in Parkinson disease usually presents as an asymmetric, “pill-rolling” resting tremor rather than an action tremor.

Bullet Summary:
Propranolol is the first-line treatment for benign essential tremor in patients with concomitant hypertension.


Question: A 29-year-old woman comes to the emergency department complaining of painful genital ulcers that have been present for 4 days as well as low-grade fever and malaise. She denies any recent travel, new sexual partners, or antibiotic use. Physical examination reveals multiple clustered vesicles and shallow ulcers in the vulvar region. A Tzanck smear shows multinucleated giant cells. Which of the following medications is most appropriate for treating her condition?

Answer: Acyclovir

Explanation:
The patient's painful genital ulcers coupled with the presence of multinucleated giant cells on a Tzanck smear are indicative of a herpes simplex virus type 2 (HSV-2) infection. Acyclovir is the treatment of choice.

Herpes infections can present with painful genital ulcers and low-grade fever. The Tzanck smear showing multinucleated giant cells further confirms the diagnosis though the diagnosis is typically made on clinical grounds and treated empirically. Acyclovir is the drug of choice for treating HSV-2 as it inhibits viral DNA polymerase, preventing the virus from replicating. The drug can reduce the duration and severity of symptoms but does not eradicate the virus entirely.

Groves (2016) emphasizes that genital herpes, caused by the herpes simplex virus (HSV), affects over 400 million people worldwide. The infection is lifelong, with vesicular outbreaks in genital areas that can ulcerate. While HSV-1 and HSV-2 are both culprits, the latter increases the risk of HIV acquisition. The polymerase chain reaction assay is the recommended diagnostic method. Nucleoside analogues are effective treatments, and pregnant women with the condition are advised antiviral prophylaxis from the 36th week until delivery to prevent neonatal complications.

Incorrect Answers:
Answer B: Amoxicillin is an antibiotic ineffective against viral infections like HSV-2. It is commonly used for bacterial infections such as streptococcal pharyngitis.

Answer C: Fluconazole is an antifungal agent is used for treating fungal infections like Candida which may cause esophagitis or vaginitis.

Answer D: Metronidazole is used primarily for anaerobic bacterial and protozoal infections.

Answer E: Trimethoprim-sulfamethoxazole is used for bacterial infections like urinary tract infections and also offers MRSA coverage.

Bullet Summary:
Acyclovir is the drug of choice for treating herpes simplex virus infections.