The patient was treated early with midazolam hydrochloride followed by maintenance therapy with phenytoin sodium. She had a cluster of seizures after 1 month, remained seizure-free for 4 months, and then developed status epilepticus. During the next 2 months, she had repeated admissions to the intensive care unit with status epilepticus or encephalopathy. Although she had lucid periods between episodes, overall she developed stepwise deterioration, with memory impairment, slurred speech, and left-sided hemiparesis. A variety of anticonvulsant agents, including carbamazepine, valproate sodium, lamotrigine, intravenous benzodiazepines, topiramate, gabapentin, and intermittent doses of phenobarbital sodium, were tried without sustained benefit. Liver function test results became abnormal while the patient was taking carbamazepine and before valproate therapy: peak alanine aminotransferase, 396 U/L (reference range, 7-28 U/L) (to convert to microkatals per liter, multiply by 0.0167); peak γ-glutamyltransferase, 1234 U/L (reference range, 7-36 U/L) (to convert to microkatals per liter, multiply by 0.0167); and peak aspartate aminotransferase, 322 U/L (reference range, 12-27 U/L) (to convert to microkatals per liter, multiply by 0.0167). Liver dysfunction persisted when valproate therapy was commenced but deteriorated when the patient received multiple drugs, including antituberculous therapy. Subsequent electroencephalograms showed frequent epileptiform discharges in the left posterior quadrant and continued diffuse slowing. Magnetic resonance imaging findings were initially normal but showed progressive abnormality with increased signal on T2-weighted images in the cortical and subcortical white matter and basal ganglia (Figure 1). The cerebrospinal fluid showed persistently low glucose levels (11-65 mg/dL) and elevated protein levels (0.11-0.47 g/dL), with few lymphocytes. Lactic acidosis (lactate levels of 61-110 mg/dL [to convert to millimoles per liter, multiply by 0.111]) was noted during the 2 weeks before death. Urinalysis showed generalized aminoaciduria and normal organic acid levels. Biopsies of the skin, muscle, and liver were nondiagnostic. Brain biopsy showed slight perivascular lymphocytic cuffing, perhaps representing cerebral angiitis.