Any of several degenerative diseases of the nervous system that involve the extrapyramidal system and the basal ganglion of the brain. Symptoms include tremors, chorea, athetosis, and dystonia. Parkinsonism is a form of extrapyramidal disease.
Extrapyramidal disorders are a group of conditions resulting from damage to or degradation of elements of the extrapyramidal system. This system consists of nerve pathways that connect motor nerve nuclei within the brain. These disorders interfere with the performance of voluntary movements, and are typically marked by involuntary movements, alterations in muscle tension, and issues with posture. Examples of these disorders include diseases like Huntington’s, Parkinson’s, and certain forms of cerebral palsy.