The cause of paralysis may be any injury that tears or compresses the nerves; it may be hemorrhage, tumor, infection, or substances toxic to nerve tissue. One of the most frequent causes of paralysis is stroke , in which hemorrhage, thrombosis, or obstruction of a cerebral vessel interferes with nerve function. Another disorder in which a resting tremor is one of the main symptoms, accompanied by slowness and poverty of movement, muscular rigidity, and postural instability is Parkinson's disease . Cerebral palsy is due to an injury to the brain motor tissue before or during birth. However, this disorder is nonprogressive. Partial or complete paralysis often accompanies multiple sclerosis .
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.
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