ABSTRACT
We present two patients with clinical features suggestive of a hyperkinetic form of encephalitis lethargica described by von Economo. While undergoing treatment for viral meningoencephalitis, they both developed comatose mentality, oromandibular dyskinesia, chorea, myoclonic jerk, oculogyric crisis, opistotonus, respiratory failure, and autonomic dysfunction. One patient died of autonomic failure while the other improved several months later. In both patients, cerebrospinal fluid exmamination revealed only pleocytosis. A brain MRI and EEG showed no specific findings. In order to control severe hyperkinetism and autonomic failure, medical treatments including L-dopa, clonazepam, and steroid pulse therapy were administereed in both cases while electroconvulsive therapy was tried in one of the cases. However, they all failed. These cases and previous reports informed us of the presence of sporadic form of encephalis.