Neuropathology of movement disorders.

This article reviews the cytoskeletal abnormalities, morphologic lesion patterns, and resulting pathophysiology of the most frequent neurodegenerative movement disorders caused by dysfunction of the basal ganglia and related neuronal loops. The following topics are discussed: Among the akinetic-rigid Lewy body disorders is idiopathic Parkinson's disease, which reveals specific lesion patterns of pathophysiologic and therapeutic relevance. Dementia with Lewy bodies characterized by cortical Lewy bodies appears intermediate between Parkinson's and Alzheimer's diseases. Tau pathologic disorders may show some clinical and morphologic overlap. Multiple system atrophy has ubiquitous oligodendroglial inclusions as a cytopathologic hallmark. Secondary parkinsonism includes drug-related, toxic, and other symptomatic disorders. Hyperkinetic disorders include CAG-related inherited diseases, showing specific genetic defects and morphologic lesions. Dystonia syndromes show inconsistent pathologic findings, and myoclonus may be related to a variety of disorders. Consensus data on clinical and neuropathologic criteria already existing for some disorders, together with molecular genetic and biochemical data will provide further insight into the complex pathophysiology and pathogenesis of movement disorders.