Balò's concentric sclerosis in a case of cocaine-levamisole abuse.

Baló's concentric sclerosis is a rare variant of multiple sclerosis. It belongs to the group of primary inflammatory central nervous system demyelinating diseases having no clear etiology. Peculiar radiological findings on magnetic resonance imaging are alternating rings of demyelinated and myelinated axons resembling an "onion bulb." We report on a case of a patient with cocaine abuse who presented with Balò's-like acute multifocal leukoencephalopathy supported by histological and radiological findings. The abuse of cocaine and its most frequent adulterant, levamisole, may induce ischemic or hemorrhagic stroke and metabolic or multifocal inflammatory leukoencephalopathy. Only a few studies described levamisole-induced leukoencephalopathy mimicking Balò round lesions. Nevertheless, it has not yet been established the correlation between them; it might also be possible that the cocaine/levamisole addiction represents just a coincidence in some of those patients affected by Balò sclerosis disease.