A man in his 30s presented with a 5-day history of vomiting, followed by lethargy and confusion. Two years prior, he was hospitalized with coma with no identifiable precipitant and an extensive workup done at that time only revealed an elevated ammonia level of 233 µg/dL (to convert to µmol/L, multiply by 0.714); etiology remained unclear but he improved with lactulose. Prior to this admission, he was working in a restaurant, did not ingest any drugs or mushrooms, and had no operations and no family history of similar problems. He was found to have hyperammonemia to 239.5 µg/dL and respiratory alkalosis (pH level, 7.482; partial pressure of carbon dioxide, 27.3 mm Hg, and partial pressure of oxygen, 109 mm Hg [to convert to kPa, multiply by 0.133]; and bicarbonate, 20.2 mEq/L [to convert to mmol/L, multiply by 1]). Liver and kidney function were normal (protein, 6.4 g/dL, and albumin, 3.4 g/dL [to convert to g/L, multiply by 10]; direct bilirubin, 0.1 mg/dL, and indirect bilirubin, 0.8 mg/dL [to convert to µmol/L, multiply by 17.104]; alkaline phosphatase, 38 U/L, aspartate aminotransferase, 22 U/L, and alanine aminotransferase, 42 U/L [to convert to µkat/L, mutiply by 0.0167]). His mental status rapidly declined despite treatment with lactulose, necessitating intubation. Head computed tomography and cerebrospinal fluid analysis were unrevealing. Ammonia levels progressively increased to 1120.5 µg/dL, requiring hemodialysis and sodium phenylbutyrate, which did not lead to significant clinical improvement. On hospital day 6, he developed continuous myoclonus due to status epilepticus (Figure 1A), which was refractory to treatment with lorazepam and levetiracetam as well as continuous midazolam, lorazepam, and propofol infusions. Plasma amino acids and urine organic acids were requested. Continuous venovenous filtration hemodialysis and carnitine treatment were started because of concern for inborn errors of metabolism. Within a few hours of transfer, his ammonia level peaked to 1960 µg/dL and he lost all brainstem activity due to diffuse cerebral edema (Figure 1B).
Sheikh Z, Wang W, Hillen M. A Young Man With Recurrent Coma and Refractory Status Epilepticus. JAMA Neurol. 2016;73(10):1243-1244. doi:10.1001/jamaneurol.2016.1788