24 July 2007
Writer's Cramp A Sign Of Brain Abnormalities
by Kate Melville
Compared to healthy individuals, people with serious cases of writer's cramp have less brain tissue in areas of the brain that connect with the affected hand, say French researchers in the latest issue of Neurology.
Writer's cramp - a form of dystonia - is an involuntary, sustained muscle contraction that sometimes occurs in people who have used the same muscles repeatedly for years. The new study involved people who had writer's cramp for an average of seven years with no other forms of dystonia. Using brain imaging, the researchers compared the brains of those with writer's cramp to a healthy control group.
They found that those with writer's cramp had less grey matter in three areas of the brain: the cerebellum, the thalamus, and the sensorimotor cortex. "It's not clear whether these abnormalities are a cause or a result of the disease," said study author Stéphane Lehéricy, of Salp�tri�re Hospital in Paris. "The fact that the brain abnormalities are in the areas that control the affected hand suggests that these differences are specific to this problem."
But another theory is that the brain structure changed and adapted as a result of the sustained repetitive movement. "Studies have shown that people with no dystonia can experience brain changes due to learning new information, which supports this theory," noted Lehéricy.
Source: American Academy of Neurology