Irelandonline- - Military service, particularly in the Gulf War, may be linked to development of a nerve disease the US Institute of Medicine said today. The evidence, however, is limited and inconsistent, the institute added.

The degenerative disease, formally known as amyotrophic lateral sclerosis, or ALS, gradually destroys the ability to control movement and patients lose the ability to move or speak, but their mind remains unaffected.

British physicist Stephen Hawking is a long-term sufferer of the disease and communicates using a computer and voice synthesiser.

According to the report five studies have been done on the subject.

Three indicated a higher rate of ALS among veterans of the 1990-91 Gulf War, one found a link to veterans who served prior to that war and one found no link at all.

�The evidence base to answer the question of whether military service increases a person�s chances of developing ALS later in life is rather sparse, so we could not reach more definitive conclusions at this time,� said Richard Johnson, chair of the committee that wrote the report.

�Because ALS occurs so rarely, any individual veteran�s chances of developing the disease are still low,� he added. Most victims die of respiratory failure within a few years.

Johnson is a professor of neurology at the Johns Hopkins University School of Medicine in Baltimore.

The individual studies had been previously reported, and the Department of Veterans Affairs asked the institute to review what was known and provide an a new overview.
In 2001, then secretary of Veterans Affairs Anthony Principi ordered that disability compensation be made available to veterans who served in the Gulf War in 1990-1991, who later developed ALS. Such compensation is not available to other veterans.

In its analysis, the institute said three studies indicated the chance of developing ALS as much as doubles for Gulf War veterans. Another study concluded that veterans who served prior to that war had 1.5 times the rate of the non-veteran population for ALS.

But some of those studies may have understated the number of ALS cases among non-veterans, and the institute said others were less useful because of limitations in the methods they used.

A fifth study found no relationship between military service and ALS.

Overall, the institute concluded, �there is limited and suggestive evidence of an association between military service and later development of ALS.�

The report called for more research to confirm this relationship and to determine the cause of any increased risk � which it said could include chemicals, involvement in traumatic events, intensive physical activity or other substances or activities.

Between 5% and 10% of the cases of ALS are thought to be inherited, the causes of the remainder remain unknown.