Writer's Cramp May Be Tied to Brain Abnormalities

ByABC News
March 24, 2008, 12:42 AM

Mar. 23 -- TUESDAY, July 24 (HealthDay News) -- Could writer's cramp be all in your mind?

New research suggests just that, with French scientists saying they've identified structural abnormalities in the brains of people prone to the painful condition. The abnormalities consist of less brain tissue in areas that govern motor skills, movement and sensory functioning.

"It's always nice to know as much as you can about something before you devise a treatment," said Dr. Tom Swift, past president of the American Academy of Neurology and professor emeritus and former chairman of the department of neurology at the Medical College of Georgia. "With a lot of dystonias, for a long time it was thought there weren't any anatomical abnormalities, even for severe dystonias. Using newer [imaging] techniques with higher resolutions, there are some areas that show abnormalities, but they're very subtle."

Writer's cramp is a dystonia, or a movement disorder that causes involuntary contractions of the muscles. The condition refers to involuntary muscle contractions of the fingers, hand or arm while writing or performing other manual tasks. It often occurs in people who have used the same muscles repeatedly for years. As a result, writing can become a painful activity, and written work can become far less legible, according to the Dystonia Society.

In one quarter of cases, the condition affects both hands. Overall, writer's cramp affects three to seven of every 100,000 people, a relatively small proportion, but it can negatively affect work, self-esteem and social life, the study authors said.

"In fully developed writer's cramp, the fingers grip the pen very tightly, and the arm drags down to the right lower corner of the page. It's pretty serious," Swift said. "Even typing can produce a similar kind of thing."

The disorder is complicated and not well understood, Swift said. "There are so many inputs that go into producing a smooth movement, it becomes one of the most complicated things in neurophysiology to figure out how the system works," he explained.