Voice Improvement After Essential Tremor Treatment via Focused Ultrasound and Deep Brain Stimulation

Objectives The primary objective of this study was to determine whether two neurosurgical procedures, deep brain stimulation (DBS) and focused ultrasound (FUS), to treat essential tremor (ET) of the upper limb also reduce vocal tremor (VT) in patients with comorbid dysphonia. Methods Twelve patients with ET and concomitant VT scheduled for neurosurgical intervention (FUS or DBS) or returning for follow-up after DBS implantation were assessed. FUS patients were assessed pre- and post-intervention and DBS patients were assessed with the electrodes turned on and off post-implantation. Three voice recordings of a sustained /a/ were obtained for each participant condition. Percent fundamental frequency variability (FFV) was calculated for each recorded sustained vowel. Additionally, blinded expert perceptual VT rating (VTR) was performed to assess subjective changes in tremors. Results Of the 12 patients, seven underwent unilateral FUS, and five underwent bilateral DBS. Mean FFV without neurosurgical intervention was 18.3 SD = 7.8 and with neurosurgical intervention was 6.3 SD = 3.0 (t (70) =8.7, p