Stimulating Muscles May Improve Musician's Dystonia

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Stimulating Muscles May Improve Musician's Dystonia

http://www.medicalnewstoday.com/articles/92702.php

Therapy that stimulates the hand muscles may help treat the

condition called musician's dystonia, a movement disorder that

causes muscles spasms in musicians, according to a study published

in the December 26, 2007, online issue of Neurology®, the medical

journal of the American Academy of Neurology.

Musician's dystonia occurs in musicians who have practiced

particular complicated movements for years. The muscle spasms are

usually painless and generally occur only when playing the

instrument.

For the study, researchers applied low-amplitude vibration to the

hand muscles in 24 people: six who had musician's dystonia, six

professional musicians with no dystonia, six healthy non-musicians,

and six people with writer's cramp, which is another type of

dystonia that occurs in people while they write.

Using transcranial magnetic stimulation, the researchers evaluated

the reaction in the sensorimotor area of the brain back to the

muscle during vibration of a single hand muscle. In healthy people,

the vibration of a muscle increases the amount of brain messages

back to the muscle and at the same time reduces the amount of

messages to muscles that did not receive vibration. In people with

musician's dystonia, vibration in any one hand muscle increases the

amount of messages to all hand muscles. In writer's cramp, vibration

to one muscle has no effect on any muscle.

Now, in an intervention that lasts only 15 minutes, muscle vibration

was applied to a thumb muscle, and the participant's attention was

either directed on that muscle itself or away from it. The reaction

of the brain's sensorimotor areas to the muscles was then tested

again using transcranial magnetic stimulation.

" Our hope is that stimulation can retrain how the brain responds, "

said study author Karin Rosenkranz, MD, with UCL Institute of

Neurology in London, United Kingdom.

The study found that the vibration intervention in which subjects

had to attend to their thumb muscle tended to restore a more normal

pattern in the sensorimotor area of the brain in people with

musician's dystonia. This effect was less pronounced in the people

with writer's cramp.

" More research is needed to see if prolonged use of stimulation can

improve hand motor function, " Rosenkranz said. " These results also

suggest that the underlying mechanism of the disorder may be

different in musician's dystonia and writer's cramp. "