Medical treatment of dystonia usually results in an incomplete response and is frequently unsuccessful. Peripheral surgical therapy is available for some focal dystonias, but may only offer temporary relief and may have unacceptable complications. We have used local injections of botulinum toxin into the appropriate muscles for treatment of disabling focal or segmental dystonia in 93 patients with torticollis, blepharospasm, oromandibular dystonia (OMD), limb dystonia, lingual dystonia, and dystonia adductor dysphonia, in addition to four patients with hemifacial spasm. Significant relief of motor symptoms was seen in 69% of the patients with blepharospasm and 64% of patients with torticollis; 74% of the latter group with pain experience relief. Relief of symptoms was noted in most patients with OMD and limb dystonia, and all with lingual dystonia, dystonic adductor spastic dysphonia, and those with hemifacial spasm. Benefit averaged 2 1/2-3 months initially; however some patients experienced longer relief with subsequent injections. Adverse effects were transient, although 2 patients developed antibodies against the toxin, and we documented evidence for distant effects in others. This approach of chemically weakening contracting muscles in focal dystonia offers many advantages over pharmacotherapy and surgical therapy. Additional experience is needed to explore the proper doses, and potential for long term adverse effects.

Although dyskinesia is a frequent and important problem in Parkinson's disease (PD), a reliable assessment measure has not been thoroughly developed and tested. We modified the Obeso dyskinesia scale to create an objective rating scale for dyskinesia assessment during activities of daily living. Thirteen physicians and 15 study coordinators involved in a clinical trial independently reviewed videotape segments of PD patients performing three tasks: walking, putting on a coat, and lifting a cup to the lips for drinking. Raters evaluated the severity of worst dyskinesia seen, the types of all dyskinesias seen, and the type of dyskinesia most associated with motoric disability. For all assessments, the total group showed statistically significant inter- and intrarater reliability. Physicians had a higher consistency than did coordinators, but for most measures the difference was not statistically significant. Physicians and coordinators found the scale easy to use and especially practical for rating dyskinesia severity and for identifying the most disabling dyskinesia. Dyskinesias can be assessed in clinical trials and warrant regular documentation.

We studied families to clarify the mode of inheritance of idiopathic torsion dystonia among the Ashkenazim. Probands had symptoms before 28 years of age, had at least one Ashkenazi grandparent, and were ascertained independently of family history and not referred by another relative. All available first- and second-degree relatives were examined, and videotapes were made. Examination notes and blinded review of videotapes led to rating of dystonia as definite, probable, possible, or absent. We determined rates of illness for first- and second-degree relatives and calculated age-adjusted lifetime risks. The methods of maximum likelihood and likelihood ratio goodness-of-fit tests were used to estimate parameters and to test dominant and recessive models of inheritance. We studied 43 probands, 146 (90.1%) of 162 living first-degree relatives, and 96 (40.2%) of 239 living second-degree relatives. Nineteen relatives had definite dystonia, and 2 had probable dystonia. Using definite cases only, the age-adjusted risk for all first-degree relatives was 15.5% and for all second-degree relatives 6.5%, with no significant sex differences; parent, offspring, and sibling risks did not differ significantly. The risks were consistent with autosomal dominant inheritance with a penetrance estimated at 29.4% using definite cases only or 32.2% using definite and probable cases. Assuming a disease frequency of 1/15,000, the gene frequency was estimated to be 1/9000.

We reviewed the records of 358 patients with various forms of focal, segmental, and generalized dystonia who had received pharmacotherapy in a systematic order, beginning with anticholinergics. If no benefit was encountered, we then tested clonazepam, baclofen, and other agents sequentially. In each situation the dosage was gradually increased until benefit or troublesome adverse effects were encountered. In this manner we obtained data on the percentage of patients who showed moderate to marked benefit. Anticholinergics were the most beneficial agent, confirming previous reports. Statistical analysis of this response revealed that benefit from anticholinergics was most likely if treatment was begun within 5 years after the onset of dystonia. From this analysis, it appears that delaying treatment beyond 5 years is likely to result in an unsatisfactory response.