A kinesthetic motor imagery study in patients with writer' cramp.

The aim was to determine if patients with writer' cramp (WC) have abnormalities in kinesthetic motor imagery of hand movements. We timed the execution and simulation of a 'finger tap task' and a 'writing task' in 9 patients with simple WC and 9 matched healthy controls. In the 'finger tap task, patients tended to be slower than controls to execute without vision (p=0.190) and to simulate the movements (p=0.094). In the 'writing task', patients were slower than controls to execute writing with vision (p=0.0001) and without vision of the movements (p=0.0001) and to mentally simulate it (p=0.04). Patients were slower to execute writing than to simulate it (p=0.021) In general, there were not significant correlations between times of execution and simulation of both tasks. In conclusion, patients with WC seem to have slowing in the processes of mental simulation of hand movements that is not specific for writing.