Heating heroin results in formation of heroin "pyrolysate" which can be inhaled.
Clinical features:
(1) history of smoking heroin base
(2) onset of neurologic signs and symptoms, most often ataxia (due to cerebellar degeneration) and dysarthria
(3) variable psychiatric complaints including depression and personality change
(4) variable altered mental status that can progress to coma
(5) variable cognitive impairment that can progress to dementia
(6) variable movement disorder
Imaging findings:
(1) spongioform leukoencephalopathy (symmetrical lesions, contrast-enhancing, hypodense on CT, hyperintense on T2-weighted MRI)
(2) less often: degeneration of the hippocampus and basal ganglia
There may be progression of clinical and/or MRI changes despite abstinence (progressive spongiform leukoencephalopathy).
Differential diagnosis:
(1) head injury
(2) CNS infection
