Focal Hand Dystonia: A Functional Imaging Study

Writer's cramp is a focal task-specific dystonia that specifically affects the act of handwriting. Although it has been generally thought that sensation is normal, there is consistent evidence for defective perception (i.e., kinaesthesia, temporal and spatial discrimination) and abnormal sensory processing in focal hand dystonia. For instance, Tempel and Perlmutter demonstrated bilateral diminished regional blood flow response in the sensorimotor cortex in patients with unilateral dystonia after vibrotactile stimulation (Tempel and Perlmutter, Brain 1990; 113: 691–707). Here we used functional magnetic resonance…