Dystonia in corticobasal degeneration.
OBJECTIVE: To characterize the clinical features, particularly dystonia, in patients with clinically diagnosed or pathologically proven corticobasal degeneration (CBD). BACKGROUND: Although dystonia has been reported in many neurodegenerative disorders, it has not been studied in CBD. Dystonia, often accompanied by painful rigidity and fixed contractures, is one of the most disabling features of CBD. METHODS: The medical records, imaging studies, and videotapes of 66 patients who satisfied the clinical criteria of CBD, evaluated between 1988 and 1998, were reviewed. The occurrence, nature, and distribution of dystonic features were analyzed and correlated with other features of CBD. RESULTS: Of the 66 patients with CBD, 39 (59.0%) had dystonia. The mean age at onset of initial symptoms was 63.9 years (range 44--75). In 20 (51.0%) patients, dystonic symptoms began in one arm, while 13 (33.0%) patients had initial leg involvement. At least one arm was affected in 36 (92.0%) dystonic patients. Although 11 (28.0%) patients had leg dystonia, the leg was the predominant site of involvement in only 1 patient. Only 12 (31.0%) patients had dystonia involving the head, neck, or trunk in the course of the disease. The diagnosis of CBD was confirmed in all 4 patients who had autopsies. CONCLUSION: In this large series of CBD patients we found that asymmetric limb dystonia, particularly affecting one arm, is a common manifestation of CBD; dystonia may be the initial manifestation of this neurodegenerative disorder. Axial or leg dystonia, without significant involvement of an arm, is rare. There is no effective treatment for this relentless disorder, except for temporary relief of dystonia and pain, with local botulinum toxin injections.