ALS Frequently Asked Questions


How many people have ALS?

It is generally estimated there are over 30,000 people living with ALS in the United States at any given time; the number worldwide is estimated at around 450,000. These numbers are hard to articulate accurately because there is no standard measure, the disease takes time to diagnose, and availability of adequate medical care for neurological diseases varies from country to country. 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- a number that is similar to the incidence of multiple sclerosis.  There are many national efforts to count and/or register individuals living with ALS, including one in the US.

Who gets ALS and why?

There are two broad categories of ALS - sporadic (sALS, essentially of unknown cause) and familial (fALS, with a direct genetic linkage). Familial ALS cases are typically identified by examining family medical history and with genetic testing. Several specific genes have been linked to the inherited form of the disease, estimated to be between 5- 10% of all cases. Recent research suggests there are more cases of ALS associated with known “ALS genes”. To date, epidemiological studies have not consistently identified clear causative agents for the remaining 90% of sporadic disease. 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 variables.  It is important to note that familial ALS and sporadic ALS are seemingly indistinguishable clinically from one another. For more information, visit our What is ALS? section of the website.

Is there a connection to military service?

A comprehensive report conducted by the National Academies' Institute of Medicine (IOM) in 2006 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 concluded 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 US Department of Veterans Affairs and the US Department of Defense concluded that those deployed in the first Gulf War (1990-1991) 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. 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.

Is diagnosis definite?

There is no single diagnostic test for ALS, however neurologists specializing in neuromuscular diseases are very capable of diagnosing it through a variety of tests and symptom monitoring. There are three type of ALS diagnosis; definite, probable, or possible ALS. If the loss of both upper and lower motor neurons is detected in two or more regions of the body, the disease is diagnosed as probable or definite ALS. If the loss of both upper and lower motor neurons is detected in only one region of the body, the disease is diagnosed as possible ALS. This distinction is primarily applicable to inclusion criteria for clinical trial enrollment. 

Is ALS fatal?

ALS is considered to be fatal, with many patients succumbing to respiratory failure and other complications of the disease. The average survival is often estimated at 30 months post symptom onset, but progression varies and up to 10% are estimated to survive 10 years or longer. Survival can also be extended if a patient opts for mechanical ventilation.

How does the disease start and is progression constant?

The initial signs of the disease vary from patient to patient, and can begin with very small or gradual changes. Many patients experience weakness in a specific muscle group, such as the leg or front part of the foot, also known as limb onset. This initial muscle weakness will spread to other parts of the body with varying rates of progression between patients. Symptoms beginning in the chest or neck and mouth area are referred to as bulbar onset.  Check out the Prognosis section of our What is ALS? page for more information. 

Is there a relation to Primary Lateral Sclerosis (PLS) or other similar diseases?

 PLS neurodegeneration is restricted to only upper motor neuron, while ALS diagnosis requires the observation of progressive loss of both upper and lower motor neurons. Publications suggest that PLS tends to be a slowly progressing disease but that the majority of diagnosed patients will eventually progress to a situation of involvement of lower motor neurons and thus the diagnosis altered to ALS.

Is there a treatment for ALS?

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 professional charged with their care.