Dystonia in corticobasal degeneration.

Although a referral bias may have resulted in a higher proportion of atypical cases and consequently an overestimation of dystonia, asymmetric limb dystonia particularly affecting one arm initially was observed in 92% of all our CBD cases. Predominant leg dystonia is uncommon, and head, neck, or axial dystonia is rare. Dystonia is often associated with myoclonus, rigidity, apraxia, alien hand phenomenon, and sensory cortical signs in the affected limb, and there are no significant differences between the occurrence of these or other features, between patients with or without dystonia. There is no effective treatment for this relentless disorder except for temporary relief of dystonia and pain with local botulinum toxin injections. Further clinicopathologic studies are needed to elucidate the anatomical and physiologic substrates of dystonia in this disorder.