Sniffed levamisole-adulterated cocaine mimicking acute demyelinating encephalomyelitis

A 38-year-old man developed headache, dysarthria and dysphasia after insufflation of cocaine. Brain imaging showed multiple white matter lesions, suggesting acute disseminated encephalomyelitis (ADEM), but the clinical features were atypical for demyelination. These lesions may represent a levamisole-associated vascular endotheliopathy, with a mechanism similar to posterior reversible encephalopathy syndrome. Levamisole is a no longer used chemotherapeutic agent but is a legally acquirable veterinary antihelminthic and is often used to adulterate cocaine. Given the rise in cocaine-related hospitalisations, this case raises awareness of an important ADEM mimic.