Acute disseminated encephalomyelitis with medial temporal lesions mimicking acute limbic encephalitis.

We describe a 59-year-old Japanese man with acute disseminated encephalomyelitis (ADEM) demonstrating medial temporal lesions on magnetic resonance images (MRI) mimicking acute limbic encephalitis. This patient had antecedent infection and developed urinary retention. Subsequently he showed various neurological manifestations including truncal ataxia, nystagmus and generalized convulsions, suggesting multifocal brain and spinal cord lesions. Brain MRI demonstrated hyperintensity areas restricted to the left hippocampus, amygdala, and inferior temporal gyrus. The cerebrospinal fluid did not show any pleocytosis or elevated protein levels, and had no evidence of herpes virus infection. Serum antineuronal antibodies were not identified. Corticosteroid therapy markedly improved the symptoms. Although these clinical features indicating multifocal central nervous system lesions were compatible with those of ADEM, none of the previously reported patients with ADEM showed lesions confined to the medial temporal lobes mimicking acute limbic encephalitis. Medial temporal lesions are characteristic features of herpetic or non-herpetic acute limbic encephalitis. Findings in our patient suggest that non-herpetic limbic encephalitis patients showing marked response to