Chasing the Dragon: A Review of Toxic Leukoencephalopathy

Abstract

The report begins with the case of an 18-year-old male who presented to a community hospital with difficulty walking and speaking. His illicit drug use history included smoking heroin. After admission to the hospital, a thorough workup was consistent with toxic heroin related leukoencephalopathy. The young man continued to decline and died approximately 2 months after his initial presentation and diagnosis. An autopsy and a thorough neuropathology examination were completed. Sections through the cerebral hemispheres and the cerebellum revealed diffuse and profound softening and discoloration of the white matter, most prominently in the occipital lobes. Microscopically, there was vacuolization and spongiosis of the white matter. The pathologic findings were consistent with the diagnosis of toxic or heroin related leukoencephalopathy. Toxic leukoencephalopathy is a rare disorder of unknown etiology linked to the smoking of heroin, known as “chasing the dragon.” The exact mechanism of the disorder is unknown, but it is thought that impurities cut into the heroin may become toxic substances upon sublimation, as the disorder is not seen with injected heroin. Currently, therapy is supportive with no effective cures available. The natural history of the disorder is variable, with an approximately 25% mortality rate. The popularity of smoking heroin is growing in the United States, and it is particularly seen with increasing frequency in new heroin users. Thus, this is an important, and likely increasingly common, effect of illicit drug use that should be recognized by forensic pathologists.