| Description |
Spasmodic dysphonia (SD) is a focal laryngeal dystonia that produces involuntary spasms of the vocal folds, resulting in a strained-strangled voice quality. Currently, there is no cure for SD, and little is known regarding possible risk factors, diseases, and/or exposures that contribute to its development. To shed light on the pathogenesis of SD, the present case-control, epidemiological investigation compared questionnaire responses obtained from individuals with SD (n=\46) and a medical treatment-seeking, control group (/i=105) regarding possible risks, diseases, and exposures. Differences between groups were examined using contingency tables, chi square analyses, odds ratios, and stepwise logistic regression. A stepwise logistic regression analysis identified several factors that were more prevalent in the SD group (p <0.15), including: (1) a personal history of mumps and intense occupational voice use; (2) an immediate family history of essential tremor, cancer, meningitis; and (3) an extended family history of multiple sclerosis, hypertension, and voice disorders. Cumulatively, these factors accounted for nearly 30% of the variance in SD group membership. The results of this case-control investigation suggest likely interactions between genetic factors, disease states and exposures, and voice use demands that contribute to the origins of SD. |
