Amyotrophic Lateral Sclerosis

Amyotrophic Lateral Sclerosis

Joanne V. Hickey

The clinical and pathological findings of amyotrophic lateral sclerosis (ALS) were first described by Charcot in 1872.1 In more than 100 years since first described, ALS remains an uncommon and poorly understood disease in which patients progressively lose the ability to speak, swallow, and move their extremities.2 ALS is a progressive neurodegenerative disease that involves both the upper and lower motor neurons. It is characterized by wasting of the muscles and progressive muscular paralysis as a result of destruction of motor neurons in the brainstem and the anterior gray horns of the spinal cord, along with degeneration of the pyramidal tracts. Some muscles become weak and atrophy, whereas spasticity and hyperreflexia are noted in others. “Amyotrophy” refers to the atrophy of the muscle fibers, which lead to weakness of the affected muscles and fasciculations. “Lateral sclerosis” refers to hardening of the anterior and lateral corticospinal tracts as motor neurons in these areas degenerate and is replaced by gliosis.3, 4

ALS is a progressive disease that leads to death most often from respiratory arrest. The cause of ALS has been elusive in spite of research efforts to understand the disease. ALS has been described as a complex genetic disorder in which multiple genetic and environmental factors combine to cause the disease. However, the contribution of any single factor is considered small.5 Most cases of ALS are sporadic with a small percentage familial. About two thirds of patients with typical ALS have a spinal form of the disease. The others have a limb form. Both will be discussed later in the chapter. Between 5% and 10% of cases are inherited as a Mendelian trait usually autosomal dominant, of which 15% to 20% are due to one of more than 100 mutations in the Cu—Zn superoxide dismutase type 1 gene (SOD1).6

In Western countries, the incidence of ALS is 2 per 1,00,000 people.7 Men are affected more frequently than women. The peak age of onset is 58 to 63 years for sporadic ALS and 47 to 52 years for familial disease.8 The overall median survival from onset of symptoms for ALS ranges between 2 and 3 years for bulbar onset and 3 and 5 years for limb onset.4, 9

Jul 14, 2016 | Posted by in NURSING | Comments Off on Amyotrophic Lateral Sclerosis

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