Prolonged survival following the inadvertent intrathecal administration of vincristine: clinical and electrophysiologic analyses.

A 23-year-old man with a lymphoblastic lymphoma accidentally received 2.0 mg of vincristine intrathecally instead of intravenously. Although he underwent immediate CSF drainage, symptoms of an ascending myeloencephalopathy developed at 48 h. This progressed to coma, initially with a diffusely slow EEG, which evolved into alpha coma. He also developed a left frontal focus of epileptiform activity. He was transferred to our institution 1 month later. His court-appointed guardian refused to allow discontinuation of supportive treatment; therefore, the evolution of the disorder can be followed for 12 months. Although alpha coma remained the predominant pattern, some EEG evolution did occur, with a progressive decrease in amplitude being most prominent. An increase in amplitude in the 10th month was accompanied by the return of some nystagmoid eye movements. The patient's lymphoma then recurred, and further treatment was not attempted. This tragic case, in which transient exposure to a microtubular poison produced severe CNS toxicity, allows some insights into the mechanisms of alpha coma.