[Therapy of dystonia in Japan]

A questionnaire about the treatment of dystonia was sent out to 585 councilors of Societas Neurologica Japonica. One hundred and sixty-eight replies (28.7%) were collected, although some of them were excluded from the analysis because of inappropriateness. 1) The number of patients previously experienced was < 10; 37 respondents (22.7%), 10-50; 83 (50.9%), 50-100; 26 (16.0%), and > 100; 17 (10.4%). 2) Oral medication was most often the first line treatment in either of generalized dystonia, blapharospasm, cervical dystonia, and writer's cramp. Botulinum toxin injection was the first or the second line treatment in 147 (87.5%) and 116 (69.0%) respondents for blepharospasm and cervical dystonia, respectively. In these two conditions, the more experienced doctors tended to prefer botulinum toxin injection to the other treatments as the first choice (Cochran-Armitage analysis; p = 0.003 for blepharospasm and p = 0.002 for cervical dystonia). 3) Among the oral drugs, anticholinergics, especially trihexyphenidyl, were the most frequent choice in generalized dystonia, cervical dystonia, and writer's cramp. For blepharospasm, clonazepam was most favored. Sedatives, especially diazepam, were also often the drug of choice in either of these disorders. The favored drugs were not related to the respondent's experience. 4) The success rate of treatment, designated as the percentage of patients who improved through any treatment so much that the respondent was satisfied with it, was the highest in blepharospasm (65.4 +/- 24.1; mean +/- SD), followed by cervical dystonia (41.2 +/- 23.4), writer's cramp (32.9 +/- 22.5), and generalized dystonia (20.4 +/- 19.8). Only in cervical dystonia, the rate was significantly higher in more experienced respondents (regression analysis; p = 0.008). In blepharospasm (p < 0.001) and cervical dystonia (p = 0.002), regression analysis indicated that the success rate was higher in the group who preferred botulinum toxin injection to oral medication as the first line treatment. These results indicate that in Japan the treatment of choice for dystonia does not always follow the therapeutic guidelines for dystonia proposed in some foreign countries. Adopting more evidence-based rationale of treatment is encouraged, because the recent progress about the treatment of dystonia, e.g. botulinum toxin injection or the stereotaxic surgery, is reshaping dystonia from a devastating to a treatable disorder.