Extrapyramidal Disease

Extrapyramidal diseases are a group of disorders affecting motor control pathways outside the corticospinal tract, leading to abnormal involuntary movements. Etiologies include Parkinson disease, drug-induced parkinsonism, and Huntington disease. Pathophysiology involves dysfunction in basal ganglia circuits, resulting in tremor, rigidity, bradykinesia, or dyskinesia. Diagnosis is clinical, supported by neuroimaging and response to pharmacologic therapy. Management includes dopaminergic medications, anticholinergics, and neurosurgical interventions such as deep brain stimulation; prognosis depends on underlying disease and therapeutic response.