ST. PAUL, MN -- September 11, 2001 --
Wearing a cooling vest can help multiple sclerosis (MS) patients with muscle
strength, fatigue and balance, according to a study published in the September
11 issue of Neurology, the scientific journal of the American Academy of
Neurology.
"This is exciting, because it's a
relatively easy treatment that brings an immediate benefit," said study author
and neurologist Jacques De Keyser, MD, PhD, of the University Hospital in
Groningen, Netherlands.
A majority of MS patients report that
their symptoms get worse in high temperatures, and that cooler temperatures
help, at least temporarily. Researchers have developed vest and head-vest
garments that attach to a box that pumps coolant fluid through tubes in the vest
and cap. But few studies have been done to determine how effective the vests are
and how the cooling works within the body to reduce symptoms.
For the study, 10 patients whose symptoms
respond to temperature changes wore the vests for an hour. Half of the patients
experienced active cooling, with the coolant set at 45 degrees. As a control
group, the other half experienced "sham" cooling, with the coolant set at 79
degrees, so the patients would feel a cool contact and would not know whether
they were receiving the treatment or not. A week later, the patients received
the other treatment.
Tests of the patients' fatigue level,
balance and muscle strength were performed before the cooling and again three
hours after the session. The patients' temperatures were taken every 15
minutes.
Researchers also tested the blood of
patients for white cell production of nitric oxide, a naturally occurring
molecule, before and three hours after the cooling session. The white cell
nitric oxide production of 12 healthy volunteers was also tested as a
comparison. Compared to the healthy volunteers, white cells in MS patients
produced more nitric oxide.
Researchers believe that nitric oxide
plays a role in reducing the activity of damaged, or demyelinated, neurons in
MS, and thus contributes to the development of symptoms.
Balance improved by an average of 20
percent for patients receiving active cooling, compared to those who received
the sham cooling. Muscle strength improved by an average of 10 percent. The
level of fatigue also improved significantly, according to Dr. De Keyser.
The level of nitric oxide decreased by 41
percent in patients receiving the active cooling. After the sham cooling,
patients' level of nitric oxide did not change. The patients' temperatures did
not drop during the cooling.
"Contrary to popular belief, the
beneficial effects of the cooling garment can't be explained simply by a direct
cooling of the central nervous system," Dr. De Keyser said. "These results raise
the intriguing possibility that lowering of nitric oxide production may play an
important role in this.
"Now more research is needed on the role
nitric oxide plays in the symptoms of MS. This could lead to efforts to mimic
the effects of cooling through drugs or other means." This study was supported
by a grant from Multiple Sclerosis International, Amsterdam.
SOURCE: American Academy of
Neurology
