Motor neuron disease

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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
See also: Amyotrophic lateral sclerosis (ALS) for the specific neuron disease sometimes referred to as “motor neurone disease”.

A motor neuron disease (MND) is any of five neurological disorders that selectively affect motor neurons, the cells that control voluntary muscle activity including speaking, walking, swallowing, and general movement of the body. They are neurodegenerative in nature, and cause increasing disability and, eventually, death.[1]


In the United States the term motor neuron disease is often used interchangeably with amyotrophic lateral sclerosis.[2] The other four motor neuron diseases are: primary lateral sclerosis, progressive muscular atrophy, progressive bulbar palsy and pseudobulbar palsy.[2] In the United Kingdom motor neurone disease is used to differentiate this disorder from the other motor neuron diseases though it is also known as amyotrophic lateral sclerosis. To avoid confusion, the annual scientific research conference dedicated to the study of MND is called the "International ALS/MND Symposium".[citation needed]

While MND refers to a specific subset of similar diseases, there are numerous other diseases of motor neurons that as a group are referred to as motor neuron disorders.[1] Examples include spinal muscular atrophy, spinobulbar muscular atrophy,


In the most common classification, the term "motor neuron disease" applies to the following five disorders which 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

Even though diseases known as spinal muscular atrophies, including the most common spinal muscular atrophy (SMA), affect motor neurons and are classified as MND by the disease terminology classification system Medical Subject Headings (MeSH), they are not classified as such by the tenth International Statistical Classification of Diseases and Related Health Problems (ICD-10) published in 1992 and thus are not discussed in this article.

See also[edit]


  1. ^ 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. 
  2. ^ a b "Motor Neuron Diseases Fact Sheet: National Institute of Neurological Disorders and Stroke (NINDS)". Retrieved 7 November 2010. 

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