Amyotrophic Lateral Sclerosis, known as ALS, is a progressive neurodegenerative disease.
It causes nerve cells to scar and harden. As the motor nerves die, the brain loses its ability to send messages that instruct the muscles to move. This leads to muscle atrophy and, eventually, a total loss of motor control. The typical survival time for people with ALS is two to five years. Some may live up to 10 or more years. Most individuals with ALS die of respiratory failure because the disease stops the muscles that control inhalation and exhalation from working.
ALS was commonly known as Lou Gehrig's Disease for decades due to the famous baseball player's retirement in 1939 because of his diagnosis. Today, awareness of the condition has grown, most notably through the viral "Ice Bucket Challenge" fundraising campaign. Despite its rising profile, ALS is a complicated disease that takes a different course in each individual.
Causes of ALS
There are two types of ALS, Familial and Sporadic. About 10% of cases are Familial ALS. It is genetically inherited. In families with the disease, parents have a 50% chance of passing the gene mutation that may cause the disease on to their children. Sporadic ALS makes up about 90% of cases. It can affect anyone, regardless of age, race or sex. Despite the prevalence of Sporadic ALS relative to Familial ALS, researchers are still uncertain about its causes. The consensus is that genetic and environmental factors combine to cause the disease. Factors include:
- Age - ALS most commonly develops between 40 and the mid-60s.
- Sex - Under the age of 65, men are 20% more likely to develop ALS than women.
- Genetics - Further study is necessary, but there is some thought that people who develop Sporadic ALS have genetic similarities to those with Familial ALS.
- Smoking - Smoking puts everyone at risk for ALS, but the risk appears to be higher for post-menopausal women.
- Environmental Toxins - Some evidence suggests that exposure to lead or other substances may cause ALS. Despite the research, an elevated risk of ALS is not yet consistently connected with a specific toxin or chemical.
- Military Service - Researchers report double the risk of ALS in individuals who served in the military. Scientists have not yet determined the connection, but theories attribute the elevated risk to exposure to certain metals or chemicals, traumatic injuries, viral infections, and extreme physical exertion.
Signs and Symptoms
ALS almost always begins with muscle twitching and weakness in a limb. Onset is typically gradual. The signs and symptoms vary between individuals because the disease affects different motor nerves as it progresses. Usually, ALS patients do not experience pain in the early or later stages. Sensation and sensitivity are usually unaffected because ALS involves the motor nerves. Monitoring for symptoms is important because ALS can appear as a different neurological condition in its earliest stages. Signs and symptoms might include:
- Muscle cramps and twitching in your arms, shoulders, and tongue
- Weakness in the legs, feet, or ankles
- Weakness in the hands or frequently dropping items
- Difficulty ambulating or performing daily activities
- Tripping and falling
- Slurred speech or trouble swallowing
- Inappropriate crying or laughing
- Cognitive and behavioral changes
Consultation with a physician is important if any symptoms or changes are detected. ALS is difficult to diagnose because there is no specific test to detect the condition. Doctors must rely on clinical exams and multiple tests. Usually, an ALS diagnosis requires ruling out an array of other neurologic conditions.
ALS is a fatal disease because there is no way to stop or reverse the damage to the nerves. Treatments focus on slowing and controlling symptom progression, managing complications, and making the patient comfortable. Doctors use medications to control and slow the decline of daily function. Other medications can prolong life expectancy by up to six months. Respiratory interventions and a ventilator are used as the breathing muscles atrophy. Patients may also undergo Physical, Occupational, or Speech Therapy. These treatments elevate function and combat the muscle atrophy that limits mobility and quality of life.