Disorders of the Extrapyramidal System
The chapter begins with an overview of human motor system control of both voluntary and involuntary movements. Movement disorders or extrapyramidal disorders are characterized by abnormal movements in conscious patients. Damage to or presumed dysfunction of the basal ganglia and their brainstem and cerebellar connections is implicated in the etiology of these diseases. Movement disorders are characterized by either excessive (hyperkinetic) or reduced (hypokinetic) activity. Hyperkinetic movements are characterized by tremor, chorea, dystonia, athetosis, ballismus, myoclonus, and tics. The reader can view videos of many hyperkinetic movement disorders. The chapter then covers in detail essential tremor, Parkinson’s disease, and Huntington’s disease with attention to their pathophysiology, major clinical features, major laboratory findings, and principles of management and prognosis.
KeywordsExtrapyramidal disorder Tremor Chorea Dystonia Athetosis Ballismus Myoclonus Tics Essential tremor Parkinson’s disease Huntington’s disease
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