Unusual imaging findings in progressive myoclonus epilepsy

We describe a patient with progressive myoclonus epilepsy (PME), white matt er hyperintensities in the corpus callosum, cerebral hemispheres, and left cerebral peduncle on magnetic resonance imaging (MRI), and positive oligocl onal bands. A phosphorus magnetic resonance spectrum was compatible with mi tochondrial dysfunction. Abnormal white matter signals are not a feature of the known PME syndromes, although they occur in Leber's hereditary optic n europathy (LHON). These abnormalities oriented the diagnosis toward mitocho ndrial disease.