Research priorities in spasmodic dysphonia

Abstract

Objective: To identify research priorities to increase understanding of the pathogenesis, diagnosis, and improved treatment of spasmodic dysphonia.

Study design and setting: A multidisciplinary working group was formed that included both scientists and clinicians from multiple disciplines (otolaryngology, neurology, speech pathology, genetics, and neuroscience) to review currently available information on spasmodic dysphonia and to identify research priorities.

Results: Operational definitions for spasmodic dysphonia at different levels of certainty were recommended for diagnosis and recommendations made for a multicenter multidisciplinary validation study.

Conclusions: The highest priority is to characterize the disorder and identify risk factors that may contribute to its onset. Future research should compare and contrast spasmodic dysphonia with other forms of focal dystonia. Development of animal models is recommended to explore hypotheses related to pathogenesis. Improved understanding of the pathophysiology of spasmodic dysphonia should provide the basis for developing new treatment options and exploratory clinical trials.

Significance: This document should foster future research to improve the care of patients with this chronic debilitating voice and speech disorder by otolaryngology, neurology, and speech pathology.

Figure 1

Discriminate function analysis results for three patient groups, MTD (muscular tension dysphonia), SD (spasmodic dysphonia) and Tremor.

Figure 2

A. The mammalian vocalization system includes areas not essential for innate vocalizations (hatched). B. Connections to the primary laryngeal motor control region in non-human primates include: the indirect pathway (pink), the cerebello-thalamo-cortical pathway (blue), and the corticobulbar pathway from M1 to the reticular formation in the brainstem (brown).