Malignant migraine: the syndrome of prolonged classical migraine, epilepsia partialis continua, and repeated strokes; a clinically characteristic disorder probably due to mitochondrial encephalopathy.

We present ten patients with classical or common migraine of increasing severity accompanied by seizures of multiple patterns and increasing severity leading to episodes of epilepsia partialis continua. Long lasting deficits associated with hypodense lesions on CT and abnormal signals on MRI, then developed. Cortical blindness, cortical deafness and dementia were common. Five of the patients died in 1-10 years. Some of these patients had markers of mitochondrial disease (ragged red fibers and serum lactate elevation) and others with the same clinical picture did not. This group of patients indicates that mitochondrial encephalopathy may exist without evidence of myopathy, that the clinical syndrome is characteristic and that it should suggest the diagnosis even in the absence of muscular abnormalities.