Amyotrophic Lateral Sclerosis (ALS)
Key points
- Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease, is a slowly progressive degeneration of nerve cells of the spinal cord, brain and brain stem, the bottom portion of the brain near the spinal cord.
- The physician also checks to see whether sensation, eye movement, and higher thought processes, such as perception, reasoning, judgment and imagination, have been affected, because they remain intact in people with ALS.
- People with ALS generally live an average of three to five years after the symptoms begin.
- Although there is no cure for ALS, new treatments are becoming available.
What Is It?
Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease, is a slowly progressive degeneration of nerve cells of the spinal cord, brain and brain stem, the bottom portion of the brain near the spinal cord. This degeneration affects only nerve cells that control muscle movements (motor neurons), resulting in the gradual loss of a person's ability to control his or her muscles. This disease does not affect mental abilities or nerves that control the senses.
Although the cause of ALS remains unknown, current theories suggest that certain chemicals, including one that transmits signals between nerve cells, may play some role in the death of motor nerve cells. ALS generally strikes patients between the ages of 50 and 70, and affects men slightly more often than women. About 5 percent to 10 percent of cases appear to be inherited.
Symptoms
Symptoms of ALS include:
- Slow, but relentlessly progressive, muscle weakness and wasting (atrophy) in the arms and legs, torso, breathing muscles, throat and tongue. Weakness usually begins in the arms and legs.
- Muscle twitching, cramps, stiffness, and muscles that fatigue easily
- Slowed speech that becomes progressively harder to understand
- Difficulty breathing and swallowing; choking
- Weight loss because of both muscle atrophy and poor nutrition caused by problems swallowing
- Sudden involuntary bursts of laughter or crying
- Changes in the way the person walks, progressing to an inability to walk
Diagnosis
Your doctor will ask about your medical history and will perform a physical examination, include a neurological examination to look for the following signs:
- A localized loss of muscle bulk (focal muscle wasting)
- Muscle twitching
- Muscle weakness in your arms and legs
- Spasticity, in which the arms or legs resist being moved by someone else.
- Abnormal tendon reflexes
- The Babinski sign, in which the toe moves upward when the sole of the foot is stroked
- Breathing problems that severely limit normal air exchange in the lungs
- Facial weakness
- Slurred speech
The physician also checks to see whether sensation, eye movement, and higher thought processes, such as perception, reasoning, judgment and imagination, have been affected, because they remain intact in people with ALS.
Your doctor will diagnose ALS based on the signs and symptoms he or she sees during your examination, and by excluding other causes of progressive movement problems. To confirm the diagnosis, your doctor also may order other tests such as electromyography (EMG) or magnetic resonance imaging (MRI) scans. In some cases, EMG and MRI scans may be performed to rule out other possible causes of symptoms.
Written and revised by
David Cohen, M.D.
Our doctors write and review articles for accuracy and keep them up to date.
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