Subclinical damage to the nigrostriatal dopamine system by MPTP as a model of preclinical Parkinson's disease: a review.

The study of subtle changes in motor and cognitive function after exposure to MPTP might serve as a guide to the very earliest stages of Parkinson's disease. Studies in nonhuman primates and man exposed to MPTP who remained asymptomatic or recovered completely are reviewed. The question of the relationship between the degree and extent of damage to the nigrostriatal dopamine system and changes in motor and cognitive (behavioral) function is addressed. What guidance they provide in the study of subclinical or preclinical Parkinson's disease is discussed.