Motor Neuron Diseases

Motor neuron diseases (MNDs) are progressive, degenerative disorders. They affect nerves in the upper or lower parts of the body. Some of the diseases are inherited, but others may be acquired. Common MNDs include amyotrophic lateral sclerosis (ALS), progressive muscular atrophy, and postpolio syndrome.


The cause(s) of most MNDs are not known. But the following factors may be involved:

  • Environmental.

  • Toxic.

  • Viral.

  • Genetic.


Generally, MNDs strike in middle age. Symptoms may include:

  • Difficulty swallowing.

  • Limb weakness.

  • Slurred speech.

  • Impaired gait.

  • Facial weakness.

  • Muscle cramps.

  • In the later stages of these diseases, respiration may be affected.


There is no cureor standard treatment for MNDs. Treatment is symptomatic and supportive. Physical therapy, drug therapy, and assistive devices may help some individuals.