Etiology of Parkinson's disease: current concepts.

The etiology of Parkinson's disease remains an enigma. Yet substantial progress toward its elucidation has been made in recent years. This disease has emerged as a particular morbid entity with a characteristic pathology and clinical expression. Viral encephalitis and heredity, which have long dominated discussions of the possible causes of the disease, appear to have been excluded. However, the possibility of a viral or subviral pathogen as the causative factor has not been excluded. The discovery of a selective dopaminergic neurotoxin, MPTP, which is active via any portal of entry, has raised the question of a toxic etiology. Current attention has focused on the search for an environmental agent. Recent studies of the Lewy body, the pathologic hallmark of Parkinson's disease, point to possible defects in neurofilament synthesis or transport. The finding that cultured cells from patients with Parkinson's disease have an abnormal radiosensitivity suggests that an acquired defect in DNA repair mechanisms may play a role.