[Essential points to differentiate various diseases causing parkinsonism]

This review article deals with the cardinal features to differentiate various conditions which present with parkinsonism other than Parkinson's disease. Special attention is paid to the distinctive clinical features, laboratory data and neuroimaging findings of frequent diseases as well as important ones including multiple system atrophy, progressive supranuclear palsy, corticobasal degeneration, Lewy body disease, drug-induced parkinsonism, vascular pseudo-parkinsonism, normal pressure hydrocephalus and manganese intoxication due to parenteral nutrition. MRI is useful to diagnose MSA, vascular pseudo-parkinsonism and manganese intoxication. Benzamide derivatives including sulpiride and metoclopramide are the main causes of drug-induced parkinsonism in recent years in Japan.