Abstract Details

Title Effect of Unilateral & Bilateral Ventral Intermediate Nucleus Deep Brain Stimulation on Vocal Tremor and Voice in Patients with Essential Tremor and Vocal Tremor. A Case Series.

Topic Movement Disorders

Presentation(s) S32 - Movement Disorders: Dystonia and Tremor Disorders (4:06 PM-4:18 PM)

Poster/Presentation
Number 004

Background

VIM DBS is a well established treatment for medically refractory ET. Although this procedure can improve VT in ET patients, VIM DBS, especially bilateral procedures, can lead to deleterious effects on other measures of vocal function.

Objective

To investigate the effect of unilateral and bilateral Ventral Intermediate Nucleus (VIM) Deep Brain Stimulation (DBS) on vocal tremor and vocal measures in patients with essential tremor (ET) and vocal tremor (VT).

Design/Methods This study was approved by the Institutional Review Board of our institution. All patients undergoing DBS surgery at our institution undergo voice and speech evaluation before surgery and six months postoperatively as standard of care. Inclusion criteria required patients to 1) have ET with VT and 2) have had VIM DBS. Vocal and motor measures were taken before and six months after surgery. Vocal tremor was measured with objective scales including Amplitude Tremor Intensity Index (ATRI) and Fundamental Frequency-Tremor Intensity Index (FTRI). Subjective vocal outcome was measured using the Voice Handicap Index -10 (VHI-10), which is a patient reported scale.

Results

Five patients met the inclusion criteria (Age 72.8±2.6 years, 4 female, 1 male, mean disease duration 29±26.2 years). Two subjects had bilateral procedure, and three had unilateral. Bilateral DBS resulted in reduction of VT by 64.2% (ATRI), 61.1% (FTRI) while unilateral DBS resulted in reduction of VT by 31.3% (ATRI), and 56.2% (FTRI) six months following surgery. Patient reported improvement in voice was 98.5% (VHI-10) for bilateral and 51.6% (VHI-10) for unilateral procedures, six months post operatively.

Conclusions

In this case series of ET patients with VT, both unilateral and bilateral VIM DBS resulted in improvement of VT and patient-reported voice measures, with more improvement seen with bilateral procedures compared to unilateral procedures. If our findings are confirmed in a larger study, VIM DBS can be a potential treatment for VT.

Authors/Disclosures
Caroline Wilson, MD (Caroline Wilson) PRESENTER	Ms. Wilson has nothing to disclose.
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Jessica Tate, MD (Atrium Health Wake Forest Baptist)	The institution of Dr. Tate has received research support from Ipsen. The institution of Dr. Tate has received research support from Boston Scientific. The institution of Dr. Tate has received research support from Revance Therapeutics. The institution of Dr. Tate has received research support from CHDI Foundation. The institution of Dr. Tate has received research support from NINDS. The institution of Dr. Tate has received research support from Michael J. Fox Foundation.
Mustafa S. Siddiqui, MD, FAAN	Dr. Siddiqui has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Boston Scientific Neuromodulation. Dr. Siddiqui has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Abbvie. Dr. Siddiqui has received personal compensation in the range of $500-$4,999 for serving as an Expert Witness for United States Department of Justice. The institution of Dr. Siddiqui has received research support from Boston Scientific Neuromodulation. The institution of Dr. Siddiqui has received research support from Abbvie. Dr. Siddiqui has received research support from Michael J. Fox Foundation. The institution of Dr. Siddiqui has received research support from National Institute of Health .