Definition

Amyotrophic lateral sclerosis (ALS) is a progressive nervous system disorder. It gradually destroys the nerves responsible for muscle movement. Over time, ALS leads to almost total paralysis of muscle movement, including respiration.

Prognosis is poor in most cases because of the progressive nature of the condition and the eventual respiratory failure. After diagnosis is made, life span ranges from 2-5 years. The five-year survival rate ranges from 14%-25%, and up to 10% of patients will survive more than 10 years. In general, the younger the age of onset, the slower the disease progresses.

The Nervous System

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Causes

The cause of ALS is not known, but in a small number of cases, it appears that genes may have played a role. Also, research has shown that there may be a reduced response to cell stress, as well as cell toxicity, related to certain protein build-up in the brain.

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition. Risk factors include:

• Having a family member with ALS
• Being in the military or having other occupations
• Having certain genetic mutations

Symptoms

Symptoms include:

• Progressive weakness in arms and legs (at first often on only one side) over weeks to months without changes in sensory abilities.
• Initial presentation may be a wrist or foot drop
• Trouble holding things without dropping them
• Frequent tripping while walking
• Shrunken muscles
• Twitchy muscles
• Unpredictable changing emotions
• Clumsiness
• Overactive reflexes
• Slurred speech
• Hoarseness
• Trouble chewing and swallowing, resulting in frequent choking and gagging
• Weight loss due to trouble eating
• Trouble breathing
• Excess salivation, drooling
• Cognition is intact
• Sensation is intact
• Trouble coughing, resulting in development of pneumonia

Diagnosis

The doctor will ask about your symptoms and medical history, and do a physical exam. There are no tests that definitively diagnose ALS, but tests may be used to rule out other medical conditions.

Tests may include:

• Electromyogram (EMG) —to look for progressive muscle weakness and twitching
• CT Scan —a type of x-ray that uses a computer to make pictures of the structures inside the head and spine
• MRI Scan —a test that uses magnetic waves to make pictures of the structures inside the head and spine
• Blood tests—to rule out metabolic, heavy metal exposure, or rarely infections (eg, Lyme disease, HIV, human T-lymphotropic virus)
• Lumbar puncture —a procedure to collect cerebrospinal fluid (CSF)
• Urine tests

Treatment

There is currently no cure for ALS.

For you and your family, a multidisciplinary approach may work best. This approach may include:

• Taking medicines
• Working with therapists and joining a support group
• Participating in religious and social activities

Treatments options include:

Prevention

There are no guidelines for preventing ALS because the cause is unknown.