The Effects of Thalamic Deep Brain Stimulation on Gait in Essential Tremor: a Kinematic Study. (P7-11.001)

Abstract

<h3>Objective:</h3> To determine the effect of ventral intermediate thalamic nucleus (VIM) deep brain stimulation (DBS) on gait parameters in patients with essential tremor (ET). <h3>Background:</h3> DBS is an established treatment for medication-refractory ET. ET can be associated with primary gait impairment; additionally, the effect of VIM-DBS on gait is currently debated, with reports ranging from a more frequently observed worsening to an improvement with therapeutic stimulation. Determining VIM-DBS effects on gait is pivotal to determine patient candidacy for this treatment. <h3>Design/Methods:</h3> Database review from our kinematics laboratory identified 27 patients (women, 15; men, 12) with ET who underwent VIM-DBS (bilateral, 5; unilateral, 22) and pre- and post-DBS quantitative gait kinematics analysis with a 3D commercial motion analysis (MA) system. Post-DBS assessments were performed on stimulation. Changes in gait outcomes from pre- to post- were expressed as effect sizes (Cohen’s d) and categorized as “small,” “medium,” or “large” using established cutoff values. Post-DBS Tremor Research Group Essential Tremor Rating Scale motor scores on and off stimulation were retrospectively reviewed and available for 22 patients; percent change of on versus off stimulation was calculated and scores were compared with paired samples t-tests. <h3>Results:</h3> Patients underwent DBS at a mean age of 69.4±8.5 years. The average percent reduction of the contralateral upper limb tremor scores on versus off stimulation was 80.4±13.4 (p&lt;0.001), 10.3±3.7 months after surgery. Postoperative MA was performed 9.6±5.9 months after surgery. Small worsening effects were observed in gait speed (d=−0.32), cadence (d=−0.39), and step length (d=−0.24), which were not statistically significant. No changes were observed in step width. <h3>Conclusions:</h3> Thalamic DBS improved tremor scores, but we observed a small, non-statistically significant, worsening trend of some gait parameters. Further study is required to clarify the observed effect of VIM-DBS on gait and identify pre-DBS gait features predictive of poor gait outcomes. <b>Disclosure:</b> Dr. Testini has nothing to disclose. Dr. McKay has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Biocircuit Technologies. The institution of Dr. McKay has received research support from NIH. The institution of Dr. McKay has received research support from the McCamish Foundation. Dr. Tripathi has nothing to disclose. Miss Genias has nothing to disclose. Mr. Skelton has received personal compensation for serving as an employee of AthenaHealth. Douglas Bernhard has nothing to disclose. Dr. Miocinovic has nothing to disclose. Dr. Aia has nothing to disclose. The institution of Dr. Buetefisch has received research support from NIH. The institution of Dr. Higginbotham has received research support from NIH/NINDS . The institution of Dr. Higginbotham has received research support from Bright Focus Foundation. The institution of Dr. Higginbotham has received research support from American Academy of Neurology. Dr. Scorr has received research support from Dystonia Medical Research Foundation. Shirley Triche has nothing to disclose. Dr. Factor has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Acorda. Dr. Factor has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Sunovion. Dr. Factor has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Alterity. Dr. Factor has received personal compensation in the range of $10,000-$49,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Lundbeck. Dr. Factor has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Biogen. The institution of Dr. Factor has received research support from Impax. The institution of Dr. Factor has received research support from Biohaven. The institution of Dr. Factor has received research support from Sunovion. The institution of Dr. Factor has received research support from Vaccinex. The institution of Dr. Factor has received research support from Voyager. The institution of Dr. Factor has received research support from Neurocrine. The institution of Dr. Factor has received research support from US World Meds. The institution of Dr. Factor has received research support from Addex. The institution of Dr. Factor has received research support from Prelinia. The institution of Dr. Factor has received research support from Medtronics. The institution of Dr. Factor has received research support from Boston Scientific. Dr. Factor has received publishing royalties from a publication relating to health care. Dr. Factor has received publishing royalties from a publication relating to health care. Dr. Factor has received publishing royalties from a publication relating to health care. Dr. Factor has received publishing royalties from a publication relating to health care. Dr. Esper has received research support from Centers for Disease Control and Prevention. Dr. Esper has received publishing royalties from a publication relating to health care.