BRAIN CELL DAMAGE UNDERLYING GULF WAR SYNDROME CAUSES ABNORMAL BRAIN DOPAMINE PRODUCTION, STUDY SHOWS
DALLAS - Sept. 14, 2000 - In a study released today, researchers say they
have found a strong link between brain cell loss on the left side of the
brain in sick Gulf War veterans and abnormal over-production of dopamine, a
neurotransmitter chemical important in such conditions as degenerative brain
diseases.
The UT Southwestern Medical Center at Dallas study, published in the
American Medical Association's Archives of Neurology, links brain cell loss
in the left basal ganglia of sick Gulf War veterans with out-of-control
production of a brain neurotransmitter chemical called dopamine. With fewer
total brain cells, the remaining dopamine-producing cells become
over-responsive and produce too much dopamine.
"This finding gives increased importance to our earlier brain scan evidence
of brain damage in these veterans," said Dr. Robert Haley, professor of
internal medicine. "Showing that the degree of brain cell injury directly
affects the level of brain dopamine production suggests that the brain
damage may be having a real effect on these veterans' brain function and is
not just a coincidental finding."
In the June issue of Radiology, UT Southwestern researchers reported that
sick Gulf War veterans had 9 percent fewer brain cells in the left basal
ganglia than healthy veterans. Previous research has shown that brain damage
in the left basal ganglia causes a dramatic increase in dopamine production,
while brain damage in the right basal ganglia has less effect.
The latest study found dopamine production was approximately twice as high
in the sick veterans with the worst brain cell damage as in the normal
veterans.
The UT Southwestern researchers said more study is necessary to determine
the significance of this finding, but one possibility is that long-term
neuro-degenerative illness may occur in some people as a result.
"We hypothesize that with injury to the brain cells that normally control
dopamine production, the cells at first go wild, overproducing dopamine,"
said Dr. Frederick Petty, a UT Southwestern professor of psychiatry and
staff psychiatrist at the Dallas Veterans Affairs Medical Center. "The
question is whether, over time, these over-stimulated cells will wear out
and die. If so, these patients could develop degenerative brain diseases
such as Parkinson's disease."
Petty said knowing that veterans could develop such diseases gives
researchers time to pursue effective treatments. Doctors performed magnetic
resonance (MR) spectroscopy imaging on 12 sick
veterans and 15 well veterans to measure the amount of neuron damage in the
basal ganglia. A series of blood tests performed by Petty measured levels of
various breakdown products of dopamine, which showed the dopamine production
problems.
The researchers decided to study basal ganglia neurons and dopamine
production because the symptoms of Gulf War syndrome strongly resemble early
symptoms of well-studied degenerative diseases of the basal ganglia like
Huntington's, Wilson's and Fahr's diseases. Typical symptoms of Gulf War
syndrome include chronic fatigue, dizziness and attacks of vertigo, general
body pain, attention and concentration problems, personality changes,
depression, and tremor.
In 1997 Haley and colleagues defined three Gulf War syndromes in the Journal
of the American Medical Association. Syndrome 1, commonly found in veterans
who wore pesticide-containing flea collars, is characterized by impaired
cognition. Syndrome 2, called confusion-ataxia, the most severe and
debilitating of the syndromes, is found among veterans who said they were
exposed to low-level nerve gas and experienced side effects from anti-nerve
gas, or pyridostigmine bromide (PB), tablets. Syndrome 3, characterized by
central pain, is found in veterans who wore insect repellent with high
concentrations of DEET and experienced side effects from the PB tablets.
Other UT Southwestern authors of the study include Dr. James L.
Fleckenstein, professor of radiology; Dr. W. Wesley Marshall, clinical
instructor of internal medicine; Dr. George G. McDonald, a former assistant
professor of radiology; and Gerald L. Kramer, a research biologist at the
Dallas VA Medical Center.
Reprinted with Permission
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