Studies find unusually high incidence of incurable ALS
WASHINGTON, Sept. 22 — Veterans of the 1991 Gulf War may have an unusually high risk of a deadly and incurable nerve disease called ALS, or Lou Gehrig’s disease, according to two U.S. studies published on Monday.
WHILE ALS is far from common among the veterans, it has appeared more than expected and at younger-than-usual ages, the separate studies found.
One of the studies was done by Dr. Robert Haley, of the University of Texas Southwestern Medical Center at Dallas —who has found much if not most of the published medical evidence supporting the idea of Gulf War Syndrome.
A second study by the U.S Department of Veterans Affairs and National Institutes of Health reaches similar conclusions. Both were published in the journal Neurology.
Haley said the finding was significant because it was “only the third real cluster of ALS cases that’s ever been documented.”
Amytrophic lateral sclerosis, also called ALS or motor neuron disease, attacks nerve cells in the brain and spinal cord, leading to muscle weakness, difficulty speaking, swallowing and breathing, and eventually total paralysis.
It affects about 30,000 Americans, and is named after baseball Hall of Fame member Lou Gehrig, who died of ALS.
About 5 percent of cases are inherited but most are unexplained. But because ALS occurs at about the same rate globally, experts believe there must be a genetic weakness that underlies the disease.
Haley identified 17 Gulf War veterans under 45 who were diagnosed with ALS between 1991 and 1998, 11 of whom have died. None had a family history of ALS or similar diseases.
Haley calculated the expected rate of ALS among this age group and found 1.38 cases of ALS per year would be expected in the Gulf War veteran population in 1998. He found five cases that year.
The VA study found that troops deployed to Saudi Arabia, Kuwait, the United Arab Emirates, Turkey and the Red Sea area had almost twice the risk of ALS as troops who stayed home.
They verified 107 cases of ALS. Of these 40 were from the 696,000 deployed troops and 67 from the nearly 1.8 million not sent overseas.
“This study addressed the question, ’Is there a problem with excessive occurrence of ALS among Gulf War veterans?”’ said Ronnie Horner of the National Institute of Neurological Disorders and Stroke, who led the second study. “We found the answer to be yes.”
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Haley noted the studies involved very small numbers of people and did not mean that most or even many Gulf War veterans need to be worried.
“The best thinking in the ALS research world is that ALS only occurs in people with a rare genetic susceptibility,” Haley said in a telephone interview.
“If you have that genetic makeup and you are exposed to many years of environmental toxins of one kind or another —and no one knows what they are — then you get the ALS. That is why usually only older people get it.”
Haley said Sarin gas “appears to be central cause in Gulf War Syndrome,” affecting about one of seven Gulf War veterans.
This may shed light on why ALS occurs.
“One of the prime suspects in civilian ALS is organophosphate pesticides. Guess what Sarin is? It is an organophosphate pesticide for humans,” he said.
Earlier this year the Institute of Medicine reported that not enough studies have been done to link pesticides or any other chemicals to Gulf War Syndrome, a poorly defined group of illnesses seen in many veterans of the 1991 conflict.
Amyotrophic lateral sclerosis (ALS), often referred to as "Lou Gehrig's disease," is a progressive disease that attacks certain nerve cells in the brain and the spinal cord responsible for voluntary muscle movement. As these motor neurons degenerate, they can no longer send the impulses that normally result in muscle movement. Once all voluntary muscle action is affected, patients become totally paralyzed. Since ALS attacks only motor neurons, sight, touch, hearing, taste and smell are not affected and for the vast majority of people, their minds, too, remain unaffected.
Early symptoms of ALS often include increasing muscle weakness, especially in the arms and legs. Speech, swallowing and breathing are also affected. When muscles no longer receive the messages from the motor neurons that they require to function, the muscles begin to waste away, or atrophy. Limbs begin to look "thinner" as muscle tissue atrophies. As the breathing muscles waste away, the patient ultimately requires permanent support from a ventilation system in order to survive.
Over 5,600 people in the United States are diagnosed with ALS each year. That's 15 new cases a day. It is estimated that as many as 30,000 Americans have the disease at any given time.
Most people who develop ALS are between the ages of 40 and 70, with an average age of 55 at the time of diagnosis. However, cases do occur in people in their 20s and 30s. The disorder is 20 percent more common in men than in women. But with increasing age, the incidence of ALS becomes more equal between men and women. Ninety to 95 percent of patients with ALS have no family history of the disease; only 5 percent to 10 percent appear to have an inherited form of ALS.
ALS is a very difficult disease to diagnose. There is no one definitive test or procedure to confirm a diagnosis — it is only through a clinical examination and series of diagnostic tests, often ruling out other diseases that mimic ALS, that a diagnosis can be established. A comprehensive diagnostic workup includes most, if not all, of the following procedures:
- Electrodiagnostic tests including electomyography (EMG) and nerve conduction velocity (NCV)
- Blood and urine studies including high resolution serum protein electrophoresis, thyroid and parathyroid hormone levels and 24-hour urine collection for heavy metals
- Spinal tap
- X-rays, including magnetic resonance imaging (MRI)
- Myelogram of cervical spine
- Muscle and/or nerve biopsy
- Thorough neurological examination
While there is not a cure or treatment available that halts or reverses ALS, there is one FDA-approved drug — Rilutek — that modestly slows the progression of ALS, as well as other drugs in clinical trials that hold promise.
Half of all people affected with ALS live at least three or more years after diagnosis. Twenty percent live five years or more; up to 10 percent will survive more than 10 years.
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