Motor neuron disease

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This article is about a category of neurological disorders. It is not to be confused with motor neurone disease which is another name for amyotrophic lateral sclerosis.
Motor neuron disease
Polio spinal diagram.PNG
spinal diagram
Classification and external resources
Specialty Neurology
ICD-10 G12.2
ICD-9-CM 335.2
DiseasesDB 8358
MeSH D016472

A motor neuron disease (MND) is any of five neurological disorders that selectively affect motor neurons, the cells that control voluntary muscles of the body. These five conditions are amyotrophic lateral sclerosis, primary lateral sclerosis, progressive muscular atrophy, progressive bulbar palsy and pseudobulbar palsy.[1] They are neurodegenerative in nature and cause increasing disability and eventually, death.[2]


Technically the term "motor neuron disease" includes five diseases: amyotrophic lateral sclerosis (ALS), primary lateral sclerosis, progressive muscular atrophy, progressive bulbar palsy and pseudobulbar palsy.[1]

In the United States the term is often used interchangeably with ALS.[1] In the United Kingdom "motor neurone disease" may be used to mean ALS.[citation needed]

While MND refers to a specific subset of similar diseases, there are numerous other diseases of motor neurons that are referred to collectively as "motor neuron disorders", for instance disease belonging to spinal muscular atrophies.[2] However, they are not classified as "motor neuron diseases" by the tenth International Statistical Classification of Diseases and Related Health Problems (ICD-10) which is the definition followed in this article.


Motor neuron diseases affect either upper motor neurons (UMN) or lower motor neurons (LMN), or both:

Type UMN degeneration LMN degeneration
Amyotrophic lateral sclerosis (ALS) Yes Yes
Primary lateral sclerosis (PLS) Yes No
Progressive muscular atrophy (PMA) No Yes
Progressive bulbar palsy (PBP) No Yes, bulbar region
Pseudobulbar palsy Yes, bulbar region No


  1. ^ a b c "Motor Neuron Diseases Fact Sheet: National Institute of Neurological Disorders and Stroke (NINDS)". Retrieved 7 November 2010. 
  2. ^ a b Ellison, edited by Seth Love, David N. Louis, David W. (2008). Greenfield's neuropathology (8th ed.). London: Hodder Arnold. p. 947. ISBN 9780340906811. 

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