Amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS) have one very important common factor: both diseases are characterized by damaged or debilitated aspects of the nervous system which can lead to severe disability. Although the two are often confused and, admittedly, share the term "sclerosis," they are very different diseases. Here’s a look at some of the most important differences between ALS and MS.
What is ALS?
ALS, also called Lou Gehrig’s disease, is a progressive neurological disease in which the motor neurons of the brain and spine degenerate and eventually begin to die. The motor neurons are responsible for movement, and ALS affects voluntary muscle movement in particular. Starting with twitches, cramps, or tremors, the muscles eventually atrophy and become completely paralyzed.
Exactly what causes ALS remains a mystery. In about 5-10% of cases, there is a familial link, and children of ALS patients have about a 50% chance of developing the disease also. The other 90% of ALS patients may see their condition arise from complications of the immune system, protein mishandling, genetic anomalies, or the potential influence of environmental toxins.
What is MS?
MS is a disease of the central nervous system in which the myelin sheath, the protective covering of nerve fibers running through the body, is damaged. The myelin sheath helps the nerves and brain communicate. As more of it becomes damaged, messages between brain and body become less reliable. Its devastation has a wide range of results, affecting each of the four types of MS differently.
Patients may experience periods of symptomatic difficulty followed by remission, or symptoms may begin to develop and progress without halt. Experts don’t know exactly what causes MS either, but current theories categorize it as an immune disorder. Effectively, the immune system designed to protect the body turns on itself and begins damaging the myelin.
Symptomatic Differences
ALS is characterized by secondary atrophy (loss of strength and bulk) of the muscles. Onset usually begins on one side of the body, or may be more global and less intense. Essentially, muscle weakness and cramping becomes muscle paralysis. This begins to interfere with daily activities, including walking, talking, chewing, swallowing, and even breathing to a fatal extent. Fatigue is common.
MS shares many common symptoms, but the exact symptoms depend on the type of multiple sclerosis diagnosed. Patients may experience muscle twitches or weakness, odd sensations (such as itching), gait disturbance, changes in vision, slurred speech, dizziness, fatigue, and bladder or bowel dysfunction.
Fatality Rates
The average patient with ALS lives for about 3-5 years, but ALS is a disease of great variability. Some patients live double that length. A very, very small percent many live more than a decade. Most ALS deaths are related to the atrophy of the muscles that control breathing. Although artificial ventilation can help, respiratory failure is a common cause of fatality in ALS cases.
MS patients, on the other hand, often live long lives dampened only by the symptoms particular to their case.
