A research team has discovered a virus in the spinal cords of
victims of amyotrophic lateral sclerosis (ALS), a fatal nervous
system disorder also known as Lou Gehrig's Disease.
Researchers at University of California, Irvine College of
Medicine (www.uci.edu) and at the Rockefeller University in Lyon,
France, found that 15 of 17 victims of ALS showed evidence of a
virus in the motor nerve cells of their spinal cords. The virus was
found in only one of 29 people who died of other causes. The virus
found is similar to Echovirus-7, an infectious agent known to cause
meningitis and rare cases of encephalitis.
The findings, which appear in the January issue of Neurology
(www.neurology.org), provide the best evidence to date of a
possible viral cause of the disease and could result in new
treatments for the disorder.
``Many researchers have suspected a viral link to ALS, but in
this study we were able to identify a virus known for nerve damage
in the exact areas of the nervous system that are affected by this
disease,'' said researcher Martina Berger, who conducted the study
in France before coming to UCI. ``We think this knowledge will help
us finally uncover what causes this disease and may someday lead us
to developing a treatment.''
In the study, the authors commented on the elusiveness of ALS:
``Although ALS has been described for the first time in 1869, its
etiology is still unknown.'' While viral -- as well as metabolic,
toxic, genetic and autoimmune -- causes have been suspected by
scientists, the study's evidence reveals the strongest viral link
to ALS thus far. This was due, in part, to researchers' use of a
highly specialized technique called a reverse-transcriptase
polymerase chain reaction, which detects the presence of viruses in
the body using trace amounts of their genetic material.
ALS became known as Lou Gehrig's disease after the legendary
baseball player died from the disorder in 1941. The disease affects
the motor nerve cells in the spinal cord, gradually weakening
muscles in the body and eventually leading to paralysis.
The disease leads to paralysis of the arm, leg, speech and
breathing muscles, according to Dr. Hiroshi Mitsumoto, professor of
neurology and head of the ALS and muscle division at
Columbia-Presbyterian Medical Center (cpmcnet.columbia.edu/dept) in
New York, and a member of the ALS Medical Advisory Committee, ALS
Association (http://www.alsa.org). It leaves patients, Mitsumoto
continued, ``unable to communicate or express themselves, unable to
breathe and eat.'' It's often described, he said, as ``a live body
in a glass coffin.''
While ALS does not severely affect the brain or, therefore,
memory and language, nearly all victims of the disease eventually
die from respiratory paralysis, usually about five years after
diagnosis.
According to the National Institutes of Health
(http://www.nih.gov), some 4,600 people in this country are
diagnosed with ALS each year. Although current treatments relieve
symptoms of the disease, no treatment has yet been found to reverse
the course of ALS.
While Mitsumoto welcomed the results, he cautioned that they do
not yet translate into treatment. The viral cause theory is not
new, he said, and while many studies in the past have revealed this
link, many others have negated it. ``Many more studies are
necessary,'' Mitsumoto concluded. ``We should always be
open-minded.''
Berger will continue her research to determine whether the virus
is, indeed, the cause of ALS, or whether it is a by-product of a
cause of ALS.
