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 total paralysis of muscle movement, including respiration.

Prognosis is poor in most cases because of the progressive nature of the condition due to eventual respiratory failure. After diagnosis is made, lifespan ranges from 2-5 years. The 5 year survival rate is 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 it appears that genes may play a role in a very small number of cases. 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
• Military personnel may have an increased risk.

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 perform 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
• MRI Scan —a test that uses magnetic waves to make pictures of the structures inside the head
• Blood tests—to rule out metabolic, heavy metal exposure, or rarely infections such as lyme disease or HIV
• Lumbar puncture —a procedure to collect cerebrospinal fluid (CSF)
• Urine tests

Treatment

There is currently no cure for ALS. The drug, called riluzole, has been approved for ALS with a clinical trial revealing a modest lengthening of survival. It may slightly improve functioning for ALS patients, although it doesn't stop disease progression.

A recent study, though, showed that the addition of lithium carbonate (a medication used to treat mood disorders) to riluzole may slow the progression of ALS and prolong survival. *¹

Other drugs are also being studied.

Treatments for the symptoms of ALS include:

A multidisciplinary approach must be taken for not only the patient, but the patient's family. This may include medications and psychological, social, religious, and ALS support groups.

Prevention

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