Recently research offers new insights into the pathogenesis, pathophysiology, and socioemotional implications of spasmodic dysphonia (SD). Among these advances are epidemiologic studies clarifying (1) SD onset and course, (2) SD risk factors, and (3) the relationships among SD course, treatment, and psychosocial impact. In this paper, I will provide a summary of recent epidemiologic and socioemotional research advances involving the onset, course, risk factors, and psychosocial impact of SD.

Objectives: This epidemiology study examined risk factors uniquely associated with spasmodic dysphonia (SD). Study Design: Case-control. Methods: A questionnaire was administered to 150 patients with SD (with and without coexisting vocal tremor) and 136 patients with other structural, neurological, and functional voice disorders (excluding SD and vocal tremor). Questions included personal and family medical histories, environmental exposures, trauma, illnesses, voice use habits and the Short Form 36. Results: Several factors were uniquely associated with SD (α=0.05), including: (1) a personal history of cervical dystonia, sinus and throat illnesses, mumps, rubella, dust exposure and frequent volunteer voice use, (2) a family history of voice disorders, (3) an immediate family history of vocal tremor and meningitis, and (4) an extended family history of head and neck tremor, ocular disease, and meningitis. Vocal tremor coexisted with SD in 29% of cases. Measles and mumps vaccines were protective for SD. Conclusions: SD is likely multi-factorial, associated with several endogenous and exogenous factors. Certain viral exposures, voice use patterns, and familial neurological conditions may contribute to the onset of SD later in life.

Objectives: This study examined voice, speech and laryngeal characteristics in Primary Sjögren’s Syndrome (pSS). Methods: Eleven patients (10 female, 1 male; mean age, 57 years; standard deviation, 14 years) from The University of Utah Division of Rheumatology provided connected speech and sustained vowel samples. Analyses included the Multi-Dimensional Voice Profile,™ the Analysis of Dysphonia in Speech and Voice,™ and dysphonia severity, speech clarity, and videolaryngostroboscopy ratings. Results: Shimmer, amplitude perturbation quotient, and average fundamental frequency differed significantly from normative values (p<.01). Cepstral Spectral Index of Dysphonia values indicated mild-to-moderate dysphonia in connected speech (mean, 20.26; standard deviation, 8.36) and sustained vowels (mean, 16.91; standard deviation, 11.08). Ratings of dysphonia severity and speech clarity using 10 cm visual analog scales suggested mild-to-moderate dysphonia in connected speech (mean, 2.11; standard deviation, 1.72) and sustained vowels (mean, 3.13; standard deviation, 2.20) and mildly reduced speech clarity (mean, 1.46; standard deviation, 1.36). Videolaryngostroboscopic ratings indicated mild-to-moderate dryness and mild reductions in overall laryngeal function. Voice Handicap Index scores indicated mild-to-moderate voice symptoms (mean, 43; standard deviation, 23). Conclusions: Individuals with pSS may experience dysphonia and articulatory imprecision, typically in the mild-to-moderate range. These findings have implications for diagnostic and referral practices in pSS.

Objective: This study examined the effects of a laryngeal desiccation challenge and two nebulized hydration treatments on phonation threshold pressure (PTP), vocal effort, and throat dryness in patients with chronic airway dryness. Study Design: Double-blind, within-subjects crossover design. Methods: Eleven individuals with Primary Sjögren’s Syndrome received a 15-minute laryngeal desiccation challenge (breathing dry air –<1% relative humidity–transorally), followed by nebulized isotonic saline or nebulized water treatments (3mL) on two consecutive weeks. PTP, as well as self-perceived vocal effort, mouth, and throat dryness were assessed before and after the desiccation challenge, and at 5, 35, and 65 minutes after the nebulized treatment. Results: The laryngeal desiccation challenge produced statistically significant increases in PTP, vocal effort, and mouth and throat dryness (p<0.05). Nebulized saline produced greater—but not statistically significant—treatment effects than water. PTP was more correlated with throat dryness than vocal effort. Conclusion: Patients with chronic airway dryness experienced phonatory changes following dry air exposure. Nebulized isotonic saline may offset this effect. Future research should explore dose-response relationships among dry air exposure, nebulized treatments, voice change and self-perceived throat dryness.