A 3-week-old African American boy is brought to the Emergency Department because of a generalized seizure 2 hours ago. The infant is highly irritable with incessant high pitched crying. The infant's weight is 2.5 kg (250 gm below birth weight), blood pressure is 70 /40 mm Hg, pulse is 145/min and respirations are 50/min. Laboratory results show:

  Blood glucose 6.6 mmol/L
  Urea nitrogen 18 mmol/L
  Serum sodium 170 mmol/L
  Serum calcium 2.1 mmol/L
  Serum magnesium 0.6mmol/L
 

Which of the following is the most likely cause of this infant’s seizure?

A. A Hypocalcemia
B. Hypoglycemia
C. Hypomagnesemia
D. Intracranial hemorrhage
E. Meningitis

The correct answer is D.

The level of serum sodium in this patient is 170 mmol/L. Infants who have hypernatremic dehydration are irritable and lethargic, and have a high-pitched cry. This type of dehydration results from a greater loss of hypotonic fluid than sodium and accounts for about 15% cases of dehydration. Because the patient has no history of diarrhea or vomiting, the hypernatremia may be due to inadequate supply of mother's milk that does not match the insensible water loss. Another cause can be the high concentration 'Of sodium in mother’s milk. Generally, after the child's birth, sodium in the colostrum decreases from its highest level to its lowest level by the fourth week. However, some mothers continue to excrete high sodium in their milk and can potentially cause recurrent hypernatremia and in some case intracranial hemorrhage in the infant.

⚠Choice A, B, C are not correct:

Hypocalcemia, hypoglycemia and hypomagnesemia are all potentially metabolic causes of seizures, however in this vignette serum calcium, glucose and magnesium are within normal limits. In patients with hypernatremic dehydration, hyperglycemia can result due to excess glucagon stimulation.

⚠Choice E is not correct:

Meningitis should be considered in any infant with a seizure with or without fever. However, the marked rise of the serum sodium makes this diagnosis unlikely.

Summarized Points:

Neonates, especially premature newborns, and young infants can develop hypernatremia from excessive sodium due to the decreased ability of immature kidneys to excrete a sodium load. This becomes a problem especially in the premature neonate when intravenous sodium bicarbonate is used to correct a metabolic acidosis. But the most common cause of hypernatremia is due to inadequate supply of mother's milk.

68-year-old woman with a 9-year history of Parkinson disease has developed worsening problems with visual hallucinations. In particular, she complains of seeing cats crawling along the floors in her house. She is taking L-dopa/carbidopa (Sinemet) and has had significant improvement in her rigidity. Which of the following drugs would be most appropriate for her psychosis?

A. Chlorpromazine
B. Clomipramine
C. Clozapine
D. Haloperidol
E. Pergolide

The correct answer is C.

All the new atypical antipsychotics have reduced extrapyramidal side effects, and clozapine has the least effect on the basal ganglia. It works predominantly as an antagonist to D1, D3, and D4 dopamine receptors. Of all the antipsychotics, it has the lowest activity against D2 receptors, which is the best measure of a drug’s potential to cause extrapyramidal side effects. Clozapine appears more effective in the mesolimbic dopamine pathways, which are disrupted in psychotic states and less effective in the nigrostriatal systems crucial to fluid movement. The main limitation to using clozapine is the risk of agranulocytosis (1 to 2%), which requires weekly leukocyte counts for the first 6 months of treatment, then every 2 weeks thereafter.

Choice A is not correct:

Chlorpromazine is an example of a typical antipsychotic. It is considered a low-potency antipsychotic and has less of a tendency to cause extrapyramidal side effects than do the high-potency antipsychotics. It is still more likely than any of the atypical antipsychotics to worsen this patient’s parkinsonism and should be avoided here.

⚠Choice B is not correct:

Clomipramine is a tricyclic antidepressant. In addition to its inhibition of norepinephrine reuptake, it is a strong serotonin reuptake inhibitor, making it a good choice for treatment in obsessive-compulsive disorder (OCD) when SSRIs are poorly tolerated. It has no role in the treatment of psychosis.

⚠Choice D is not correct:

Haloperidol is one of the high-potency anti-psychotics, and it may produce prominent extrapyramidal side effects. It would very likely improve this patient’s psychosis but would also worsen her parkinsonian symptoms. In general, haloperidol is never used in patients with Parkinson disease.

⚠Choice E is not correct:

Pergolide is a dopamine agonist and may be used as adjuvant therapy in Parkinson disease to lessen the daily Sinemet requirement. It would tend to produce the same CNS side effects as Sinemet, including dyskinesias and visual hallucinations.

Summarized Points:

Clozapine has less extrapyramidal side effects due to less activity against D2 receptors, therefore is good choice to use for Parkinson psychosis.

An 88-year-old female presents from a long-term care facility after several hours of vomiting witnessed by the staff.  She has multiple other comorbidities and is unable to provide history, but her examination is remarkable for abdominal distention, tympany, and a lack of auscultated bowel sounds. Vital signs include pulse 108/min, respiratory rate24/min, blood pressure 160/78 and pulse oximetry 93% on room air. A lateral decubitus abdominal film is obtained as the patient is unable to stand due to contractures and is attached. What is the most likely historical feature leading to this patient’s diagnosis?


A. Constipation
B. Hypertension
C. Recent antibiotic use
D. History of atrial fibrillation

The correct answer is A.

The plain film shows the typical “coffee-bean” sign seen in sigmoid volvulus.  A history of constipation, neuropsychiatric illness, bedridden, or neurologic disease with paralysis are risk factors for the development of this diagnosis, which can lead to a large bowel obstruction.  Early in diagnosis, the patient can present with mild distension, nausea, and tympanic abdomen but late in the presentation they can have pain, severe distension and volvulus can even continue on to perforation due to high pressures causing the severe distension of the large bowel proximal to the volvulus point.  The distension can also lead to an elevated diaphragm thus compromising respiration.

⚠ Choice B and D are not correct:

These are both risk factors for the development of mesenteric ischemia, which presents with abdominal pain out of proportion to examination. It also presents in older patients with abdominal pain and bright red blood per rectum. Plain abdominal films are usually normal in these patients but rarely can show pneumatosis intestinalis. Hypertension is also a risk factor for development of aortic aneurysms/dissection.

⚠ Choice C is not correct:

Recent antibiotic use predisposes a patient to the development of antibiotic-associated colitis or Clostridium difficile. Plain film imaging is typically negative. A CT scan may show evidence of thickened bowel wall, but the ultimate diagnosis of C. difficile is by identifying the toxin in a patient’s stool sample.

Summarized Points:

Volvulus can be identified on plain radiography by the "coffee-bean" or "bent-tire" sign

A 4-year-old girl is brought to the emergency department after ingesting an unknown tablet. She was playing on the kitchen floor at her grandfather's house when her mother saw her put a tablet in her mouth. Her parents cannot remember what medications the grandfather takes, but he has a history of hypertension, hyperlipidemia, and type II diabetes mellitus. The child's temperature is 36 C (96.8 F), blood pressure is 88/46 mm Hg, pulse is 120/min, and respirations are 28/min. She is pale, lethargic, and difficult to arouse. Serum glucose level Is 1.3 mmol/L (3.3-5.8). Ingestion of which of the following is the most likely etiology of this patient's symptoms?

A. Atenolol
B. Clonidine
C. Metformin
D. Nifedipine
E. Glipizide

The correct answer is E.

Sulfonylureas are oral hypoglycemic agents used to treat type II diabetes mellitus. In children and infants, a single tablet (e.g., 2 mg dose) can cause threatening hypoglycemia, which typically manifests as nonspecific irritability or lethargy. Autonomic changes such as tachycardia and diaphoresis are less common than in adults but may also be present. In severe cases, seizures, coma and death may occur ("One pill can kill").

Children with sulfonylurea ingestion require extremely close monitoring for hypoglycemia with frequent fingerstick glucose levels. Children should also be assessed for co-ingestions with laboratory studies and an electrocardiogram.

Treatment consists of decontamination with activated charcoal if the ingestion occurred <2 hours prior to presentation. Activated charcoal is less likely to be helpful if symptoms of hypoglycemia are present as absorption has already occurred. Hypoglycemia should be treated with intravenous dextrose (0.5-1 g/kg). Octreotide, a somatostatin analog that decreases insulin secretion, can be used for the treatment of resistant hypoglycemia. Any child with a possible sulfonylurea exposure should be observed in the hospital for 24 hours.

⚠Choice A is not correct:

Beta blacker (e.g., atenolol) ingestion, even one tablet, can be fatal in young children. Beta Bookers can cause hypoglycemia, but they also cause bradycardia, hypotension, and bronchospasm rather than tachycardia.

⚠Choice B is not correct:

Clonidine, an α-2 adrenergic agonist used to treat hypertension, is also toxic in small doses. Clonidine toxicity typically causes altered mental status, bradycardia, and hypotension rather than tachycardia and hypoglycemia.

⚠Choice C is not correct:

Metformin toxicity presents with abdominal pain, nausea, vomiting, and lactic acidosis. Children are unlikely to be symptomatic after ingestion of a single tablet.

⚠Choice D is not correct:

Calcium channel blocker (e.g., nifedipine) ingestion can also be fatal at very low doses in children and presents with bradycardia, hypotension, and hyperglycemia.

Summarized Points:

Sulfonylureas are oral hypoglycemic agents that can be lethal to children in very small doses. Symptoms (e.g., irritability, lethargy, diaphoresis) are primarily due to hypoglycemia. Treatment consists of activated charcoal within 2 hours, intravenous dextrose, and octreotide for persistent hypoglycemia

A population of 2000 women is known to have a 20% prevalence of breast cancer. Digital mammography is used as a screening test. with a sensitivity of 90% and a specificity of 70%. women with concerning mammography findings are followed up with a biopsy to rule out cancer. What is the total number of women who have negative digital mammogram findings?

A. 400
B. 1160
C. 1120
D. 1600
E. 840

The correct answer is B.
 

Prevalence = Total case (disease)/Total population

Sensitivity= True positive /Total disease

Specificity= True Negative /Total Healthy

The prevalence of breast cancer is 20%. In a population of 2000, 20% is equal to 400 women with known breast cancer. Specificity refers to the proportion of people without the disease who test negative. Of the 2000-400 1600 women without breast cancer. 70% or 1120 will have negative mammograms. This means that 1600-1120 = 480 women without breast cancer will have a positive screening mammogram.

The total number of negatives = true negatives + false negatives =1120+40 =1160.

Summarized Points:

Know how to set up the table by using sensitivity, specificity, and prevalence

A 32-year-old woman comes to the emergency department because of a 12-hour history of a severe headache. She does not smoke or use illicit drugs. Her blood pressure at admission is 180/104 mm Hg. Physical examination shows a bruit in the epigastric region. Fundoscopy shows bilateral optic disc swelling. Which of the following investigations is most likely to confirm the diagnosis?

A. Echocardiography
B. Serum PTH
C. High-dose dexamethasone suppression test
D. Oral sodium loading test
E. CT angiography

The Correct answer is E

Fibromuscular dysplasia (FMD) typically occurs in young persons, particularly women <35 years of age. The abrupt onset of hypertension in a young patient with a lateralizing abdominal bruit suggests the diagnosis. For patients with suspected renal artery fibromuscular dysplasia, CT angiography (CTA) is the initial imaging modality of choice.  CT angiography is a noninvasive imaging method that has high accuracy in confirming the diagnosis of fibromuscular dysplasia, which most commonly affects the renal and carotid arteries. Renal artery stenosis due to FMD leads to hypertension, as seen here. Imaging typically shows a so-called “string of beads” appearance of the renal arteries due to segmental hyperplasia of the tunica media. Other imaging methods that can be used to diagnose FMD are duplex ultrasonography and magnetic resonance angiography.

Patients with fibromuscular dysplasia are at risk for aneurysm formation and/or dissection, most commonly of the renal, carotid, and intracranial arteries. Patients with fibromuscular dysplasia should undergo at least a one-time assessment for intracranial aneurysm with brain CTA or MRA.

⚠Choice A is not correct:

Echocardiography with Doppler is used e.g., to confirm coarctation of the aorta. Although coarctation of the aorta can lead to hypertension, other symptoms are also typically present, such as hypotension and claudication of the lower extremities, or a continuous murmur below the left clavicula and between the shoulder blades. An abdominal bruit, however, would not be expected. Echocardiography has no role in diagnosing fibromuscular dysplasia.

⚠Choice B is not correct:

Serum PTH levels are used in the diagnostic evaluation of hyperparathyroidism. Primary hyperparathyroidism can lead to hypertension due to progressive calcification of the arteries and heart muscle. However, this condition is typically associated with other findings, such as nephrolithiasis, constipation, gastric ulcers, psychological symptoms (e.g., depression, fatigue), and/or bone, muscle, and joint pain. In addition, primary hyperparathyroidism would not explain this patient's abdominal bruit.

⚠Choice C is not correct:

A high-dose dexamethasone suppression test is used to confirm Cushing syndrome. While Cushing syndrome is a common cause of secondary hypertension, it is usually accompanied by other symptoms, such as obesity, hirsutism, and easily bruisable skin with stretch marks. In addition, Cushing syndrome would not explain this patient's abdominal bruit.

⚠Choice D is not correct:

Oral sodium loading test is used to confirm primary hyperaldosteronism. Although primary hyperaldosteronism is a common cause of secondary hypertension in young people, symptoms of hypokalemia, such as fatigue or muscle weakness, are also typically present. In addition, primary hyperaldosteronism would not explain this patient's abdominal bruit.

Summarized Points:

In a young woman (<35 years of age) with a hypertensive emergency (blood pressure of 185/125 mm Hg, papilledema, severe headache) and an epigastric or flank bruit on examination, fibromuscular dysplasia (FMD) is the most likely diagnosis. The best initial test for renal FMD is duplex ultrasonography and/or CT angiography. The common finding is “string of beads” sign which is from segmental hyperplasia of the media and beaded stenosis.

A 77-year-old female is brought to the emergency department with a complaint of shortness of breath and progressive dyspnea. Her medical history is significant for a previous myocardial infarction 5 years ago and mild congestive heart failure. The patient has also had several episodes of ventricular tachycardia that ultimately required cardioversion. She is currently taking a prophylactic medication and has not had any recurrent arrhythmias. On physical examination, she is in moderate respiratory distress and she has dry rales throughout her lung fields. Her blood pressure is 138/75 mmHg, pulse is 96 /min, respiratory rate is 28/min, temperature is 37.2 C (99.1 F). Chest x-ray is normal, but CT scan of the chest shows diffuse ground-glass opacities. Which of the following is contributing to this patient’s symptoms and clinical findings?

A. Amiodarone
B. Digoxin
C. Lisinopril
D. Bleomycin
E. Losartan

The correct answer is A.

Amiodarone is an antiarrhythmic medication that may be used for prophylaxis or treatment of serious arrhythmias, especially ventricular arrhythmias. This patient has a history of ventricular tachycardia, and therefore has an indication to be taking amiodarone. This drug has many toxicities, and therefore when started the patient must have baseline pulmonary function tests, thyroid function tests, and liver function tests due to the toxicity involving each of these organs. Other notable side effects include blue-gray discoloration of the skin, corneal deposits, and peripheral neuropathy. This patient developed pulmonary fibrosis as a result of chronic amiodarone use.

⚠Choice B, C, and E are not correct:

Digoxin, lisinopril, and losartan are not associated with pulmonary fibrosis.

⚠Choice D is not correct:

Bleomycin can cause pulmonary fibrosis, but it is an antineoplastic drug and the patient has no reason to be taking this medication.

Summarized Points:

Amiodarone is an antiarrhythmic medication that may be used for prophylaxis or treatment of serious arrhythmias, especially ventricular arrhythmias. This drug has many toxicities, and therefore when started the patient must have baseline pulmonary function tests, thyroid function tests, and liver function tests due to the toxicity involving each of these organs.