Amyotrophic lateral sclerosis (ALS)

Amyotrophic lateral sclerosis (ALS) is a nervous system disease that attacks nerve cells called neurons in your brain and spinal cord.

Amyotrophic lateral sclerosis (ALS) is a nervous system disease that attacks nerve cells called neurons in your brain and spinal cord. These neurons transmit messages from your brain and spinal cord to your voluntary muscles - the ones you can control, like in your arms and legs. At first, this causes mild muscle problems. Some people notice

  • Trouble walking or running
  • Trouble writing
  • Speech problems

Eventually, you lose your strength and cannot move. When muscles in your chest fail, you cannot breathe. A breathing machine can help, but most people with ALS die from respiratory failure.

The disease usually strikes between age 40 and 60. More men than women get it. No one knows what causes ALS. It can run in families, but usually it strikes at random. There is no cure. Medicines can relieve symptoms and sometimes, prolong survival. 

More than 12,000 people in the U.S. have a definite diagnosis of ALS, for a prevalence of 3.9 cases per 100,000 persons in the U.S. general population, according to a report on data from the National ALS Registry. ALS is one of the most common neuromuscular diseases worldwide, and people of all races and ethnic backgrounds are affected.

 No one knows what causes ALS. It can run in families, but usually it strikes at random.

The onset of ALS may be so subtle that the symptoms are overlooked. The earliest symptoms may include fasciculations, cramps, tight and stiff muscles, muscle weakness affecting an arm or a leg, slurred and nasal speech, or difficulty chewing or swallowing. These general complaints then develop into more obvious weakness or atrophy that may cause a physician to suspect ALS.

No one test can provide a definitive diagnosis of ALS, although the presence of upper and lower motor neuron signs is strongly suggestive. Instead, the diagnosis of ALS is primarily based on the symptoms and signs the physician observes in the patient and a series of tests to rule out other diseases. Physicians obtain the individual’s full medical history and usually conduct a neurologic examination at regular intervals to assess whether symptoms such as muscle weakness, atrophy of muscles, hyperreflexia, and spasticity are getting progressively worse.

There is no cure. Medicines can relieve symptoms and, sometimes, prolong survival.