What are motor neuron diseases?

Motor neuron diseases (MNDs) are a group of neurological conditions that progressively destroy motor neuron cells. Motor neuron cells are critical to health and normal, everyday functioning because they control many voluntary muscle actions, such as swallowing, breathing, speaking, talking, hand gestures, and walking. This is different from sensory nerves that permit you to sense touch, pain and temperature.

Normally, nerve cells in the brain send commands through the spinal cord to muscle nerve cells to perform movements. When nerve cells are damaged or destroyed by a motor neuron disease, muscles cannot receive the brain’s messages. This results in muscle weakening and wasting, fasciculations (uncontrollable twitching), spasticity, and stiffness in the legs and arms.

Amyotrophic lateral sclerosis (also known as ALS or Lou Gehrig’s disease) is the most common motor neuron disease, accounting for approximately 85% of motor neuron disease (Source: CDC).

Other motor neuron diseases include:

  • Post-polio syndrome, also known as PPS, is a syndrome that affects polio survivors decades after recovery from poliomyelitis.

  • Primary lateral sclerosis, also known as PLS, is a rare disease that causes progressive weakness of voluntary muscles.

  • Progressive bulbar palsy is a disease that affects the brain stem causing weakness and problems with swallowing, speaking and chewing.

  • Progressive muscular atrophy is a disease that causes weakness in the hands and lower body.

In most cases, the cause of motor neuron diseases is not known; however, a small percentage of cases are inherited. Some motor neuron diseases, such as ALS, are ultimately fatal, while others, such as PLS, impact bodily functions and quality of life, but do not necessarily result in death. While there is no cure for MNDs, treatments are available that may reduce symptoms and help you live as active a life as possible. These treatments vary depending on the specific underlying disease and the severity of the symptoms.

Seek prompt medical care if you develop problems with muscle function or weakness; difficulty with speaking, swallowing or chewing; muscle spasticity or cramps; clumsiness; or other unexplained symptoms. Early diagnosis and treatment may help slow the progression of the disease and improve your quality of life. Seek prompt medical care if you have been diagnosed with a motor neuron disease and your symptoms worsen or you experience new symptoms.

Seek immediate medical care (call 911) if you, or someone you are with, have serious symptoms or complications of motor neuron disease, such as difficulty breathing or choking.


What are the symptoms of motor neuron diseases?

Symptoms of motor neuron disease (MND) are related to problems with communication between your nerves and muscles. Symptoms of motor neuron diseases vary depending on the specific disease.

Early symptoms of MNDs

You may experience symptoms daily or just once in a while. In the early stages of disease, symptoms may be subtle and include:


What causes motor neuron diseases?

Motor neuron diseases (MNDs) are the result of problems with communication between motor neurons (nerves) and muscles. Normally, nerves in the brain send commands to muscle nerve cells to carry out specific movements. When nerve cells along this chain of command are damaged or destroyed by motor neuron disease, they cannot receive the brain’s messages. This leads to the symptoms of motor neuron... Read more about motor neuron diseasescauses


How are motor neuron diseases treated?

While there is no cure for motor neuron diseases (MNDs), some drug treatments can help reduce the severity of symptoms. One drug, riluzole (Rilutek), may help slow damage to the nerves that control muscles. Other treatments and medical support, such as physical therapy, speech therapy, assisted breathing apparatuses, and home hospice care, are aimed at helping you and your family cope with the ... Read more about motor neuron diseasestreatments

Medical Reviewer: William C. Lloyd III, MD, FACS Last Annual Review Date: Sep 6, 2013 Copyright: © Copyright 2014 Health Grades, Inc. All rights reserved. May not be reproduced or reprinted without permission from Health Grades, Inc. Use of this information is governed by the HealthGrades User Agreement.

This Article is Filed Under: Brain and Nerves