A case of valproate-induced hyperammonemic encephalopathy: look beyond the liver

Figure 2: Electroencephalogram taken on days 4 and 7 after the patient was admitted to hospital: (A) High-amplitude slowing has largely disappeared, and normal 10–11-Hz α waves are becoming apparent in the posterior head regions, suggestive of neurologic improvement. (B) Electroencephalogram appears almost completely normal, with well-developed α waves in the posterior head regions (arrows). Note: C = central, F = frontal, FP = frontpolar, O = occipital, T = temporal. Odd and even numbers in the electrode locations refer to the left and right hemispheres respectively.