ECFMG Medical Knowledge & Clinical Science 3 — Questions and Answers
Question 1: A 35-year-old woman presents with ascending weakness starting in her legs 2 weeks after a GI illness. CSF shows elevated protein with normal cell count. What is the most likely diagnosis?
- Multiple sclerosis
- Myasthenia gravis
- Guillain-Barré syndrome (Correct answer)
- Botulism
Correct answer: Guillain-Barré syndrome
Guillain-Barré syndrome presents with ascending paralysis post-infection and the classic CSF finding of albuminocytologic dissociation (high protein, normal cells).
Question 2: A 50-year-old alcoholic man presents with confusion, ataxia, and ophthalmoplegia. What is the immediate treatment?
- Glucose infusion
- Thiamine IV then glucose (Correct answer)
- Haloperidol for delirium
- Naloxone administration
Correct answer: Thiamine IV then glucose
Wernicke's encephalopathy requires immediate IV thiamine before glucose to prevent precipitation or worsening of the thiamine-deficient state.
Question 3: A 40-year-old woman has a butterfly rash, arthralgia, and a positive ANA. Her anti-dsDNA is elevated and complement levels are low. Which organ complication carries the worst prognosis in her condition?
- Pleuritis
- Lupus nephritis (Correct answer)
- Discoid skin lesions
- Raynaud's phenomenon
Correct answer: Lupus nephritis
Lupus nephritis is the most serious organ complication of SLE and is a major cause of morbidity and mortality if untreated.
Question 4: A neonate develops projectile vomiting at 3 weeks of age. The vomit is nonbilious and the infant is hungry after vomiting. Ultrasound shows pyloric wall thickness of 5 mm. What is the definitive treatment?
- Proton pump inhibitor therapy
- Pyloromyotomy (Correct answer)
- Balloon dilation of pylorus
- Atropine infusion
Correct answer: Pyloromyotomy
Hypertrophic pyloric stenosis is definitively treated with Ramstedt pyloromyotomy after correcting electrolyte abnormalities.
Question 5: A 62-year-old man with type 2 diabetes has a creatinine of 2.1 mg/dL and eGFR of 38 mL/min. Which antidiabetic agent requires dose adjustment or avoidance?
- Sitagliptin
- Empagliflozin
- Metformin (Correct answer)
- Glipizide
Correct answer: Metformin
Metformin is contraindicated when eGFR falls below 30 and should be used cautiously below 45 due to risk of lactic acidosis in renal impairment.
Question 6: A patient with HIV has a CD4 count of 80 cells/μL and presents with headache, fever, and a positive India ink preparation of CSF. What is the treatment of choice?
- Fluconazole alone
- Amphotericin B plus flucytosine (Correct answer)
- Voriconazole
- Caspofungin
Correct answer: Amphotericin B plus flucytosine
Cryptococcal meningitis induction therapy in HIV uses amphotericin B deoxycholate plus flucytosine for the first 2 weeks.
Question 7: A 22-year-old man has painless testicular swelling. Ultrasound shows a solid intratesticular mass. Which tumor marker is MOST specific for seminoma?
- Alpha-fetoprotein (AFP)
- Beta-hCG
- Placental alkaline phosphatase (PLAP) (Correct answer)
- LDH
Correct answer: Placental alkaline phosphatase (PLAP)
PLAP is most specific for seminoma; AFP elevation indicates non-seminomatous elements and rules out pure seminoma.
ECFMG Medical Knowledge & Clinical Science 3
A 35-year-old woman presents with ascending weakness starting in her legs 2 weeks after a GI illness.
CSF shows elevated protein with normal cell count.
What is the most likely diagnosis?