The Impact of Vocal Tremor on Deglutition: A Pilot Study

Objective Vocal tremor (VT) poses treatment challenges due to uncertain pathophysiology. VT is typically classified into two phenotypes: isolated vocal tremor (iVT) and essential tremor‐related voice tremor (ETvt). The impact of phenotypes on upper aerodigestive tract physiology during swallowing remains unclear. Qualitative and quantitative measures were employed to characterize tremor phenotypes and investigate the effects on swallowing physiology. Methods Eleven ETvt participants (1 Male, 10 Female; x̄ age = 74) and 8 iVT participants (1 Male, 7 Female; x̄ age = 71) swallowed 20 mL boluses in cued and uncued conditions under standardized fluoroscopic visualization. Sustained/a/productions were captured to assess the rate and extent of fundamental frequency (F0) modulation. Penetration and Aspiration Scale (PAS) scores were obtained and swallowing biomechanics were captured using Swallowtail™ software. Participants also completed the Swallowing Quality of Life (SWAL‐QOL) questionnaire. Results Hypopharyngeal transit was faster in both VT phenotypes compared with Swallowtail™ normative reference data. Total pharyngeal transit times, however, were only faster in patients with iVT, relative to reference data. No significant differences were observed on the SWAL‐QOL or PAS between tremor phenotypes. SWAL‐QOL scores revealed that these patients rarely reported dysphagia symptoms. Conclusions Subtle differences in swallowing patterns were observed across VT phenotypes, possibly related to adaptive mechanisms resulting in quicker pharyngeal bolus transit. Most patients did not report swallowing issues or dysphagia symptoms. This study is foundational for larger studies on this challenging population. Level of Evidence 4 Laryngoscope, 134:4599–4603, 2024 This study investigates the impact of vocal tremor phenotypes, isolated vocal tremor (iVT), and essential tremor‐related voice tremor (ETvt) on upper aerodigestive tract physiology during swallowing. Distinct biomechanical patterns were observed, suggesting potential adaptive mechanisms contributing to faster pharyngeal bolus transit. Despite these differences, most individuals with vocal tremor did not report dysphagia symptoms, indicating the potential presence of compensatory strategies influencing swallowing patterns without perceived impairment.