ALS affects the muscles of arms, legs, posture, face, tongue, speech, swallowing, and eventually, breathing. It may also affect emotion, resulting in periods of inappropriate or exaggerated emotional responses. What it does not affect is thinking or intelligence, sensation/sense of touch, taste, smell, hearing, sight, eye movement, involuntary muscles of the heart, bowel, bladder, or sexual function.

The two currently identified forms of ALS are "Sporadic" and "Familial." The most common type is "Sporadic ALS," accounting for over 90% of the cases of ALS. Here the cause is unknown and may affect anyone at random. "Familial ALS" accounts for the remaining cases (less than 10%) and is caused by inheriting a dominant gene from one parent. In this case, there would be a family history of ALS among blood relatives and also a 50/50 chance of the affected person passing it onto their children. If neither parent or other blood relatives have ALS, you'd expect to have the Sporadic form and, therefore, not expect to pass it onto your children. Presently there is no blood or genetic screening test to detect "the ALS gene" for all familial forms of ALS, but, there is a test for the chromosome 21 defect. However, only approximately 20% of the people who have familial ALS have this defect. These studies are designed for research, & aren't yet available for general testing. It takes months to get results & there can be problems with the tests, (ie. unreadable.) For information call ALSA at (800)-782-4747 or the Les Turner Center (708)-679-3311.

ALS is a very uncommon disease, affecting about 1 per 100,000 each year. It more often affects people over age 40, men slightly more than women. The usual cause of death is through respiratory complications. Survival time, as well as the course of the disease (the order in which symptoms develop) varies widely. Historically, from textbooks, ALS has an average survival time of 3 to 5 years, with about 20% of those affected living past 5 years. The classic "Progressive Bulbar Palsy" variant has a survival time of 1 to 3 years. Let me state clearly that there are a lot of reasons not to get caught up with numbers on survival time. First, those numbers are averages based on thousands of people and that doesn't tell us, as individuals, how we'll do. Every individual's course is different. Second, there are documented cases of spontaneous remission and long term ALS survivors. Third, with the availability of gastrostomy feeding tubes, home ventilators, etc, not only length of survival, but quality of life can be extended. Finally, it's far too early to tell what impact these new research drugs, (and others to follow), will have with early and long term treatment. Also, I firmly believe that state of mind has a significant influence over survival time. I'll comment more on that under "My Personal Philosophy" at the end of "Practical Tips."

Regarding the disease process, there are 2 types of motor nerves that supply voluntary muscles; both are affected in ALS. One type are called Upper Motor Neurons (UMN's). These begin in the brain and extend into the spinal cord. When these nerves are affected, the result is spasticity, weakness and over-reactive reflexes. The second type are called Lower Motor Neurons (LMN's). These begin where UMN's end (in the Anterior Horn Cell region of the spinal cord), and each travels to a specific muscle. When these are affected, the result is marked weakness leading to paralysis, muscle wasting and diminished to lost reflexes. As these nerves become dysfunctional you may see muscle fasciculations. When symptoms begin in the arms or legs it may be referred to as "Limb Onset ALS."

To make matters a little more complicated, there is a special subset of nerves that come directly from the brainstem and control specialized functions like speech and swallowing. When symptoms arise from these nerves they may be referred to as "Bulbar" symptoms. Bulbar is a traditional term for brainstem.

A diagnosis of ALS is made by "Clinical Diagnosis." This means that no single test can prove the diagnosis. Instead, it requires a thorough exam and many tests, sometimes over a period of weeks, all of which need to be interpreted by an experienced neurologist in order to confirm or reject a diagnosis.