ALS Frequently Asked Questions

At any given time, there are over 30,000 patients diagnosed with ALS living in the United States; the number world-wide is estimated to be at least 450,000. Generally speaking, someone is diagnosed with ALS every 90 minutes. The life-time incident rate for an average person is often estimated at between 1 in 400 to 1 in 600 people - similar to that of multiple sclerosis.

There are two broad categories of ALS - sporadic (sALS, essentially of unknown cause) and familial (fALS, with a direct genetic linkage). fALS cases are typically identified by examining family medical history and with genetic testing. Several specific genes have been linked to this inherited form of disease, estimated to be between 5 - 10% of all cases of ALS. To date, epidemiological studies have not consistently identified clear causative agents for the remaining 90% of cases. ALS seems to affect males and females at the same rate, and there have been no indications that prevalence is higher based on ethnicity or other demographic variable.

A comprehensive report conducted by the National Academies' Institute of Medicine (IOM) supports the association between service in the U.S. military and increased risk of developing ALS. The IOM was charged with reviewing and evaluating all relevant scientific literature on ALS and veterans. It concludes that there exists "suggestive evidence of an association between military service and later development of ALS." Since 2000, studies have been conducted to assess the ALS incidence rate in Gulf War veterans. Most notably, a study jointly funded by the VA and DOD concluded that those deployed in the first Gulf War were twice as likely to develop ALS as their non-deployed counterparts, and potentially, at younger ages. Air Force veterans, it determined, faced the highest risk, at 2.7 times that of those not serving. In 2005, The Harvard School of Public Health broadened the case for ALS's military relevance. Its epidemiological study found that men with a history of any military service in the last century were nearly 60% more likely to die of ALS than men in the general population. The recent IOM report refers to this study as "well-designed and well-conducted." In July 2008, in response to the evidence, Secretary of Veterans Affairs Dr. James B. Peake announced that ALS is to be considered a presumptively compensable illness for all veterans with 90 days or more of continuously active service in the military.

ALS is essentially a diagnosis of exclusion; elimination of other possible diseases until ALS is left as the only diagnosis.

ALS is considered to be a fatal disease, with more than 75% patients succumbing to respiratory failure. The average rate of survival is often estimated at 30 months after symptom onset, but progression varies, and up to 10% are estimated to survive 10 years or longer. Survival could also be potentially extended if a patient opts for mechanical ventilation.

The initial signs of ALS varies from patient to patient. Many patients experience weakness in a specific muscle group, such as in the leg, or the front part of the foot resulting in difficulty walking, refered to as 'foot drop'. This initial muscle weakness will, with varying progression, typically spread to other parts of the body. Symptoms beginning in the chest or neck and mouth area is often referred to as bulbar onset.

Currently, there is no effective therapeutic approved for use by the FDA that has been identified to stop the disease's progression or prevent onset. Rilutek is a drug that has been approved for use in the treatment of ALS; however it offers a very modest effect which has usually been described as a three-month life extension. The effectiveness of Rilutek varies from patient to patient, and all medical treatment decisions should be made in careful consultation with one's physician or other qualified medical professionals charged with their care.

Here at TDI, we evaluate ALS drug candidates in a mouse model of the disease called SOD1 G-93A. This is a widely accepted model for human ALS. This model is based on a version of the mutated human SOD1 gene, which is associted with 10-20% of inheritated cases of the disease. Mice or rats bred to carry multiple copies of the altered human gene develop symptoms very similar to clinical ALS. These animals provide a basis for evaluation of drug efficacy potential in studies that are similar to a clinical trial as well as a source for tissue for experimentation.