NINDS Motor Neuron Diseases Information Page

What are Motor Neuron Diseases?

The motor neuron diseases (MNDs) are a group of progressive neurological disorders that destroy cells that control essential muscle activity such as speaking, walking, breathing, and swallowing.  Normally, messages from nerve cells in the brain (called upper motor neurons) are transmitted to nerve cells in the brain stem and spinal cord (called lower motor neurons) and from them to particular muscles.  When there are disruptions in these signals, the result can be gradual muscle weakening, wasting away, and uncontrollable twitching (called fasciculations).  Eventually, the ability to control voluntary movement can be lost.  MNDs may be inherited or acquired, and they occur in all age groups.  MNDs occur more commonly in men than in women, and symptoms may appear after age 40.  In children, particularly in inherited or familial forms of the disease, symptoms can be present at birth or appear before the child learns to walk.

The causes of sporadic (noninherited) MNDs are not known, but environmental, toxic, viral, or genetic factors may be implicated.  Common MNDs include amyotrophic lateral sclerosis (ALS), progressive bulbar palsy, primary lateral sclerosis, and progressive muscular atrophy. Other MNDs include the many inherited forms of spinal muscular atrophy and post-polio syndrome, a condition that can strike polio survivors decades after their recovery from poliomyelitis.

Is there any treatment?

What is the prognosis?

What research is being done?

• NINDS Amyotrophic Lateral Sclerosis (ALS) Information Page
  ALS, Amyotrophic Lateral Sclerosis or Lou Gehrig's disease information sheet compiled by the National Institute of Neurological Disorders and Stroke (NINDS).
• Amyotrophic Lateral Sclerosis (ALS) Fact Sheet
  
  Amyotrophic Lateral Sclerosis (ALS or Lou Gehrig's disease) fact sheet compiled by the National Institute of Neurological Disorders and Stroke (NINDS).
• NINDS Spinal Muscular Atrophy Information Page
  Spinal muscular atrophy (SMA) information page compiled by the National Institute of Neurological Disorders and Stroke (NINDS).
• NINDS Post-Polio Syndrome Information Page
  Post-Polio syndrome information compiled by the National Institute of Neurological Disorders and Stroke (NINDS).
• Post-Polio Syndrome Fact Sheet
  
  Post-Polio Syndrome fact sheet compiled by the National Institute of Neurological Disorders and Stroke (NINDS).
• NINDS Primary Lateral Sclerosis Information Page
  Primary lateral sclerosis (PLS) information sheet compiled by the National Institute of Neurological Disorders and Stroke (NINDS).
• NINDS Monomelic Amyotrophy Information Page
  Monomelic amyotrophy (Benign Focal Amyotrophy) information sheet compiled by the National Institute of Neurological Disorders and Stroke (NINDS).
• Testimony on Amyotrophic Lateral Sclerosis, May 2000
  NINDS Director's testimony before the Senate Appropriations Subcommittee on Labor, Health and Human Services, Education and Related Agencies on Amyotrophic Lateral Sclerosis (ALS), May 18, 2000.