REVERSIBLE FOCAL BRAIN EDEMA IN A PATIENT WITH MELAS (MITOCHONDRIAL MYOPATHY, ENCEPHALOPATHY, LACTIC-ACIDOSIS, AND STROKE-LIKE EPISODES) SYNDROME

We describe a patient with MELAS (mitochondrial myopathy, encephalopat hy, lactic acidosis, and stroke-like episodes) syndrome and frequent b rief partial seizures arising from the occipital lobe. After a cluster of elementary and complex partial seizures, the patient developed sig nificant reversible focal occipital brain edema. We suggest that the p athogenesis of this prominent edema is a consequence of chronically de creased nucleotide levels in the brain, leading to an altered influenc e of excitatory amino acid neurotransmitters on membrane ion flux.