Amyotrophic Lateral Sclerosis (ALS)
Amyotrophic Lateral Sclerosis (ALS) is a progressive disease that destroys the motor neurons in the nervous system. The vast majority of cases occur sporadically.
The mean onset of ALS occurs in the patients’ 50’s and 60’s with increasing risk until the age of 74. Males are affected 1.5-1.7 times as often as females. The prevalence in the United States is 3-8 cases per 100,000 people.
Symptoms
ALS usually begins with weakness in the arms and/or legs with progression in the affected area first, followed by more generalized weakness, atrophy and twitching (fasciculations) of the muscles. When the motor neurons die, the associated muscles become weak, atrophied and eventually die. Some patients develop cramping of the affected muscles. Eventually, most muscular function is affected so patients can lose their ability to talk, swallow and eventually to breathe.
Some individuals with ALS will develop problems with processing information and memory, but in general patients will remain fully alert and aware. The sensations are also not involved. The mean survival rate is 3-4 years, but about 4-10% of patients survive more than ten years. ALS is responsible for about 1/700 deaths in the United States. Death is usually peaceful with the patient dying in their sleep of respiratory failure.
Diagnosis
The diagnosis is a clinical one, usually with signs of involvement of the central and peripheral nervous system. The most accurate diagnostic test is an EMG and nerve conduction study. Muscle enzymes are frequently elevated in the serum, but they are less specific.
Treatment
There is no cure for ALS, but Riluzole may increase survival for a few months. It tends to be more effective in patients with bulbar onset (problems swallowing, speaking and/or breathing), in older patients and when given early in the course of the disease. On the whole, treatment is supportive with physical therapy, assistive devices, respiratory support and special feeding tools being helpful as the disease progresses.