Myoclonus dystonia: possible association with obsessive-compulsive disorder and alcohol dependence.

BACKGROUND: Inherited myoclonus-dystonia (M-D) is a disorder that is characterized primarily by myoclonic jerks and is often accompanied by dystonia. In addition to motor features, psychiatric disease is reported in some families. METHODS: To determine whether the same genetic etiology underlies both neurologic and psychiatric signs, the authors studied psychiatric symptoms in nonmanifesting carriers (NMC), noncarriers (NC), and manifesting carriers (MC) in three families demonstrating linkage of M-D to the 7q21 locus. Interviewers administered the computerized version of the Composite International Diagnostic Interview. Algorithms for the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition diagnosis of obsessive-compulsive disorder (OCD), generalized anxiety disorder, major affective disorder, alcohol abuse, alcohol dependence, drug abuse, and drug dependence were used. Rates of disorders among the MC, NMC, and NC were compared. RESULTS: Of 55 participating individuals, 16 were MC, 11 were NMC, and 28 were NC. The rate of OCD was greater in carriers (5/27) compared with NC (0/28) (p = 0.023). It was also greater in the symptomatic gene carriers (4/16) compared with the asymptomatic group (1/11) (p = 0.022). Alcohol dependence was increased in the symptomatic carriers (7/16) (p = 0.027), but not in the carrier group overall (7/27). CONCLUSION: OCD may be associated with the DYT11 M-D gene; however, a larger sample is necessary to confirm this finding. Alcohol dependence is highly associated with expressing symptoms of M-D. This may be explained by self-medication with alcohol to improve motor symptoms of M-D.

Myoclonus-dystonia, obsessive-compulsive disorder, and alcohol dependence in SGCE mutation carriers.

Although myoclonus and dystonia are the hallmarks of myoclonus-dystonia (M-D), psychiatric features, particularly obsessive-compulsive disorder and alcohol dependence, have been reported in three families linked to chromosome 7q21. As the epsilon sarcoglycan (SGCE) gene for M-D was subsequently identified, we evaluated the relationship between psychiatric features and SGCE mutations in these original and two additional families and confirm that OCD and alcohol dependence are associated with manifesting mutated SGCE.

A new screening tool for cervical dystonia.

BACKGROUND: Family studies of dystonia may be limited in part by small family size and incomplete ascertainment of dystonia in geographically dispersed families. Further, prevalence estimates of dystonia are believed to be underestimates, as most studies are clinic-based and many individuals do not present to a physician or are misdiagnosed. As a low-cost highly sensitive screening tool is needed to improve case detection for genetic and epidemiologic studies, the authors developed the Beth Israel Dystonia Screen (BIDS), a computer-assisted telephone interview. OBJECTIVE: To evaluate the validity and utility of a computer-assisted telephone interview in screening for cervical dystonia. METHODS: The BIDS was administered and videotaped neurologic examinations performed on 193 individuals from 16 families with cervical and cranial dystonia. With use of a final rating of definite dystonia, as determined by video review of a systematic neurologic evaluation, as the gold standard, the predictive value of a subset of questions from the BIDS was assessed. RESULTS: A positive response to at least two of five screening questions had a sensitivity for cervical dystonia of 100% and a specificity of 92%. With use of a positive response to three or more questions, definite dystonia was determined with 81% sensitivity and 97% specificity. CONCLUSIONS: The Beth Israel Dystonia Screen (BIDS) identifies cervical dystonia with excellent sensitivity and specificity in a family-based sample. The authors recommend the BIDS for family studies, but cross-validation in a population sample is advisable before applying this method to epidemiologic studies.