Journal of Neurology, Neurosurgery, and Psychiatry 1988;51:745-752 Occasional review The relevance of the Lewy body to the pathogenesis of idiopathic Parkinson's disease

SUMMARY The Lewy body is a distinctive neuronal inclusion that is always found in the substantia nigra and other specific brain regions in Parkinson's disease. It is mainly composed of structurally altered neurofilament, and occurs wherever there is excessive loss of neurons. It occurs in some elderly individuals and rarely in other degenerative diseases of the central nervous system. In 273 brains of patients dying from disorders other than Parkinson's disease, the age-specific prevalence of Lewy bodies increased from 3-8 % to 12-8 % between the sixth and ninth decades. Associated pathological findings suggest that these cases of incidental Lewy body disease are presymptomatic cases of Parkinson's disease, and confirm the importance of age (time) in the evolution of the disease. In view of the common and widespread occurrence of this disorder we propose that endo-genous mechanisms operating in early life may be more important than environmental agents in the pathogenesis of Lewy bodies and Parkinson's disease. Neuronal inclusions called Lewy bodies are present in many surviving cells of the substantia nigra in all cases of Parkinson's disease fulfilling the UK Parkin-son's Disease Society Brain Bank clinical diagnosti