Periodic lateralized epileptiform discharges in mitochondrial encephalomyopathy.

Periodic lateralized epileptiform discharges (PLEDs) were transiently recorded during the acute phase of cerebral stroke-like episodes in three patients with mitochondrial encephalomyopathy (MEM). One of the patients developed stroke-like episodes three times, always accompanied by PLEDs. These discharges were recorded from the hemisphere responsible for the stroke-like episodes or from the more severely affected hemisphere when bilateral hemispheres were affected. Although PLEDs have been rarely reported in MEM, this disease should be considered as a differential diagnosis of cerebral infarction with PLEDs.