Suspected MPTP-induced parkinsonism.

The case of an intravenous heroin user who developed parkinsonian symptoms from the age of 28 years is presented. Neuropathologic examination revealed a marked loss of neurons and gliosis with the presence of Lewy bodies in the substantia nigra and locus ceruleus; they stained variably with antibody to ubiquitin and negatively with antibodies to tau and neurofibrillary tangles. Pseudo-Lewy bodies were also seen. Electron microscopy showed features in keeping with other electron microscopic studies of Lewy bodies in idiopathic Parkinson's disease and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced inclusion bodies in monkeys. Given that the deceased was a known heroin user, the rarity of the early age of onset, that MPTP is a recognized cause of parkinsonism in the drug abusing population, the absence of history of exposure to neuroleptics and the neuropathologic features, the parkinsonism was considered to be due to MPTP contamination of heroin. However, given the onset of parkinsonism 11 years prior to death it was not possible to obtain samples of the heroin injected to test for the presence of MPTP. Therefore it could not be absolutely excluded that this was a case of idiopathic Parkinson's disease occurring at a very young age in a heroin abuser. The immunohistochemical and electron microscopic features of Lewy bodies in such a case have not been previously described. The similarity of the neuropathological features to those of idiopathic Parkinson's disease and MPTP-induced parkinsonism further strengthens the hypothesis of MPTP or an MPTP-like agent being a cause of idiopathic Parkinson's disease.