Seizure Disorders USMLE Step 1 Practice Question
A 19-year-old woman presents to her neurologist 6 weeks after starting valproic acid for newly diagnosed idiopathic generalized epilepsy. She reports tremor, progressive weight gain of 8 pounds over this period, and diffuse hair loss. She also notes that her menstrual period has not occurred in the past 2 months. Vital signs are stable with BP 118/76 mmHg, HR 88 bpm, RR 16/min, and temperature 37.2°C. Laboratory studies show: serum ammonia 95 μmol/L (normal <50), AST 28 U/L, ALT 31 U/L, total bilirubin 0.8 mg/dL, TSH 2.1 mIU/L. Which of the following best explains her clinical presentation?
Answer choices
- AHepatotoxicity with acute liver failure requiring immediate medication discontinuation
- BHypothyroidism secondary to valproic acid metabolism of thyroid hormone
- CHyperammonemia with secondary amenorrhea and endocrine dysfunctionCorrect answer
- DTeratogenic effects of valproic acid manifesting as congenital abnormalities
- EDrug-induced systemic lupus erythematosus with multi-organ involvement
- FCarbamazepine cross-sensitivity with Stevens-Johnson syndrome
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