ST. PAUL, MN – 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 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," 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.
The American Academy of Neurology, an association of more than 17,500 neurologists and neuroscience professionals, is dedicated to improving patient care through education and research. For more information about the American Academy of Neurology, visit its web site at http://www.aan.com