Amyotrophic lateral sclerosis

Summer B Gibson MD (

Dr. Gibson of the University of Utah received honorariums from Guidepoint and GLG for consulting work and from CLS Behring and Cytokinetics as an advisory board member. Dr. Gibson's spouse owns stock in Recursion Pharmaceuticals.

Louis H Weimer MD, editor. (

Dr. Weimer of Columbia University has received consulting fees from Roche.

Originally released June 21, 1996; last updated June 28, 2019; expires June 28, 2022

This article includes discussion of amyotrophic lateral sclerosis, Charcot disease, Lou Gehrig disease, motor neuron disease, Aran-Duchenne disease, Duchenne-Aran disease, familial amyotrophic lateral sclerosis, flaccid bulbar palsy, PLS, primary lateral sclerosis, progressive bulbar palsy, progressive crural palsy, progressive muscular atrophy, and spastic bulbar palsy. The foregoing terms may include synonyms, similar disorders, variations in usage, and abbreviations.


Amyotrophic lateral sclerosis is a devastating neurodegenerative disease characterized by progressive muscle weakness without notable sensory loss. There are two U.S. Food and Drug Administration-approved medications. Both have demonstrated modest effects on slowing disease progression: riluzole, approved in 1995, and edaravone, approved in 2017. In this article, the author reviews clinical manifestations, risk factors, symptomatic management, and clinical trials and provides updates on recent genetic discoveries.

Historical note and terminology

Aran believed this syndrome was a muscular disease and was the first to use the term “progressive muscular atrophy” (Aran 1850). Cruveilhier first noticed the atrophy of the anterior spinal roots and thought progressive muscular atrophy was a myelopathic disorder (Cruveilhier 1853). Charcot and Joffroy proposed the term “amyotrophic lateral sclerosis” when they noticed the involvement of the corticospinal tract (Charcot and Joffroy 1969). Brain used the term “motor neuron disease” to emphasize the connections between progressive muscular atrophy, amyotrophic lateral sclerosis, and progressive bulbar palsy (Brain 1962). The term “motor neuron disease” also highlights the variety of involvement of upper and lower motor neurons. Rowland suggested using the plural form, “motor neuron diseases,” to describe all of the diseases of the anterior horn cells and the motor system, including spinal muscular atrophies (Rowland 1982). Spinal muscular atrophies are clinically and pathologically distinct from amyotrophic lateral sclerosis.

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