STUDY: Parkinson's Starts Years Before Symptoms

[Murray Charters <mcharters@xxxxxxxxxxxxxx>]

STUDY: Parkinson's Starts Years Before Symptoms
Findings Could Someday Help Doctors Prevent the Brain Disorder

By Charlene Laino
WebMD Medical Reference

Reviewed By Michael Smith, MD
on Tuesday, May 04, 2004

May 4, 2004 (San Francisco) -- If new research pans out in future trials, 
doctors may someday be able to predict who
will develop Parkinson's disease more than a decade before symptoms appear.

More importantly, once drugs that can ward off the Parkinson's are developed, 
it may be possible to prevent the brain
disorder marked by tremors, muscle stiffness, and trouble with balance and 
coordination, reports G. Webster Ross, MD,
staff neurologist at the Honolulu Department of Veterans Affairs in Hawaii.

"The important thing is that there is a long period of time during which people 
are destined to develop Parkinson's
disease, with gradual loss of cells going on in the brain, but they don't know 
it," he says. "There are no signs or
symptoms."

"If we could identify these people and have an intervention that slows or 
prevents the brain cell loss, we could
actually prevent the disease," Ross tells WebMD.

13 Years Earlier

Reporting at the American Academy of Neurology 56th Annual Meeting, Ross says 
his study showed that the loss of brain
cells that leads to Parkinson's disease starts an estimated 13 years before the 
diagnosis.

For the study, Ross and colleagues examined the brains of 13 deceased men who 
had Parkinson's disease and those of 175
men who died at similar ages but did not have the disorder. The researchers 
counted the number of brain cells in the
section of the brain affected in Parkinson's -- an area known as the substantia 
nigra.

The average number of cells was significantly lower in the men with Parkinson's 
than in the other men. Also, the longer
the men had had Parkinson's disease, the lower their brain cell count, Ross 
says.


By using sophisticated statistical methods that graphed brain cell loss over 
time, the researchers then estimated that
at the time of diagnosis, the men with Parkinson's disease had, on average, 40% 
fewer brain cells in the substantia
nigra than those without Parkinson's disease, he says. With further analysis, 
the researchers estimated that the loss
of brain cells starts about 13 years prior to the diagnosis of the disease.

More Study Needed

Philip Su, MD, clinical associate professor of neurology at the State 
University of New York at Stony Brook, says he
was impressed with the study. "Before we really had no long-term studies; now 
we do," he says. "It helps clinicians to
know that the disease is progressive and to know about how long a time period 
goes by between the start of nerve cell
loss and actual symptoms."

But Stanley Fahn, MD, H. Houston Merritt professor of neurology at Columbia 
University in New York City and immediate
past president of the American Academy of Neurology, tells WebMD that while 
interesting, further study is needed.

Ross agrees, stressing that the findings are still preliminary. The next step, 
he says, will be to go back and try to
replicate the findings in larger numbers of people.

Additionally, in order to track brain cell loss over time in people who are 
alive, better methods of imaging the brain
are still needed, Ross says. "We have some special scans but we're still trying 
to refine them," he tells WebMD.

SOURCE: WebMD - May 4, 2004


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