STUDIES PROBE LINK BETWEEN ALS AND DRUG USE

HONOLULU, April 2, 2003 -- In the search for causes of amyotrophic lateral sclerosis (ALS), researchers have examined potential triggers from electric shock to lead poisoning. New studies, reported today at the 55th annual meeting of the American Academy of Neurology in Honolulu, probed the disease’s connection to drug use – from illicit, recreational drugs to seemingly harmless painkillers.

ALS attacks muscle-controlling nerve cells in the spinal cord, often leading to paralysis and death from respiratory failure within three to five years of diagnosis. It’s a relatively rare disease, affecting some five in 100,000 people worldwide. Though some cases are genetic, in most, the cause is unknown.

So, when Stacy Rudnicki, director of the MDA Clinic at the University of Arkansas in Little Rock, had two new ALS patients within two months of each other who reported that they had previously abused methamphetamine (MET) drugs, she dug deeper.

Examining the medical histories of 61 ALS patients seen at the clinic between July 2000 and January 2003, Rudnicki and her team discovered that six – 10 percent – had used MET chronically, or intensely for a short period of time.

The connection was particularly strong in Rudnicki’s young patients. Among patients who had used MET, average onset of the disease was at 36 years of age; among those who hadn’t used MET, it was 58 years. In all, 40 percent of patients under age 45 reported a history of MET abuse.

“Identifying chronic MET abuse in a group of young patients with [ALS] raises the question as to what role it may have played in the development of their disease,” Rudnicki wrote in a statement accompanying her presentation at the meeting. She cited animal studies showing that MET can trigger brain cells to undergo a cell death process known as apoptosis.

Other scientists examined a possible link between ALS and non-steroidal anti-inflammatory drugs (NSAIDS), which include aspirin, ibuprofen, and a bevy of new-generation arthritis drugs. Previous studies have shown that NSAIDS might protect against Alzheimer’s disease, but at the meeting, two studies on ALS came up with conflicting results.

Lorene Nelson at Stanford University in Stanford, Calif., headed a team that examined NSAID use in 187 people with ALS and 393 people without the disease. Non-aspirin NSAID use was associated with a twofold increased risk of ALS in men, but coincided with a slightly reduced risk of ALS in women.

“There is no strong evidence that suggests NSAID use is protective against the development of ALS,” Nelson concluded.

However, a study from the MDA/ALS Clinical Research Center at the University of Wisconsin in Madison suggests that treatments for arthritis and other bone and joint diseases – perhaps NSAIDs – might delay the onset of ALS.

Center Director Benjamin Brooks was part of a team that examined the co-occurrence (co-morbidity) of ALS with bone and joint diseases, including arthritis and traumatic injuries. Using the ALS CARE database, a collection of medical data on nearly 4,000 ALS patients, they identified 736 patients who had pre-existing bone and joint disease. ALS symptoms in that group appeared significantly later (60 years) than in ALS patients without pre-existing bone and joint disease (53 years). There was no difference in survival between the two groups.

Brooks and his colleagues concluded that “factors (treatment, co-morbidity) associated with pre-existing bone and joint disease may protect patients from developing ALS.”