A number of diseases can significantly affect the proper functioning of the nervous system. Parkinson's disease, Huntington's disease, myasthenia gravis, and amyotrophic lateral sclerosis (commonly known as Lou Gehrig's disease) are some of the more severe diseases affecting the nervous system. Strokes, which are related to circulatory disorders, also may have permanent effects on the nervous system. Certain plant derivatives, such as belladonna, cocaine, and caffeine, have a variety of stimulatory, inhibitory, and hallucinatory effects on the nervous system.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.