Arc de cercle and dysautonomia from anoxic injury.

Autonomic dysregulation and catatonic posturing are well described following acute cerebral injury. Others have referred to this as diencephalic seizures, sympathetic storms, midbrain dysregulatory syndrome, and, most recently, paroxysmal autonomic instability with dystonia. Some of these syndromes can evolve into malignant catatonia requiring electroconvulsive therapy. Here we report a case of hanging associated anoxic brain injury resulting in severe dysautonomia and an extreme opisthotonus (arc de cercle).