[Acute edematous encephalopathy presenting with refractory generalized status epilepticus: an autopsy case]

A previously healthy, 29-year-old man developed generalized convulsion with disturbed consciousness 3 days after the flu-like symptoms. On the next day, his convulsion evolved into generalized status epilepticus (GSE) that was unresponsive to administration of various anticonvulsants. Then, intravenous anesthetic agents, including midazolam, propofol and vecuronium sodium, were continuously infused. During the following 9 days, despite of high-dose infusion of these anesthetic agents, his GSE could not be suppressed, and complex partial seizure with secondary generalization frequently occurred. The patient was comatose and mechanically ventilated, whereas the brainstem reflexes were preserved. Electroencephalogram revealed a diffuse slowing of the background activity and occasional focal spike and wave complexes with secondary generalization. Cerebrospinal fluid analysis showed pleocytosis and elevated protein concentration. Cranial CT scans obtained on day 8 demonstrated brain edema. On day 10, his GSE ceased with abolition of the brainstem reflexes, and he lapsed into brain death resulting from the progressive brain edema. Over the following six days, his systemic circulation gradually worsened, and he died on day 16. On postmortem examination, the brain was markedly edematous and showed the findings consistent with acute anoxic encephalopathy with extensive circulatory stasis. Mild gliosis was observed in the insular cortex, yet no evidence of inflammatory disease was found throughout the brain. This patient was characterized by acutely progressive severe brain edema without inflammatory changes, suggesting that his primary disease was acute toxic encephalopathy presumably induced by viral infection. His GSE was refractory and unresponsive to the intensive treatment with the intravenous anesthetic agents. This case epitomizes the difficulties in controlling refractory seizures in some patients with encephalopathy or encephalitis.