Amyotrophic lateral sclerosis
Commonly called Lou Gehrig disease, after the New York Yankee first baseman who died of this disorder, amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease causing muscular atrophy. Other motor neuron diseases include progressive muscular atrophy and progressive bulbar palsy. Onset occurs between ages 40 and 70. A chronic, progressively debilitating disease, ALS is rapidly fatal.
The disease is progressive, with death resulting from respiratory paralysis (the median survival is 3 to 5 years), and it’s three times more common in men than in women. The exact cause of ALS is unknown, but 5% to 10% of ALS cases have a genetic component. In these cases, it’s an autosomal dominant trait that affects men and women equally.
ALS and other motor neuron diseases may result from:
a slow-acting virus
nutritional deficiency related to a disturbance in enzyme metabolism
metabolic interference in nucleic acid production by the nerve fibers
an autoimmune disorder that affects immune complexes in the renal glomerulus and basement membrane.
Precipitating factors for acute deterioration include trauma, viral infections, and physical exhaustion.