Lateralized Subthalamic Stimulation for Axial Dysfunction in Parkinson's Disease: A Randomized Trial

Abstract

Background Patients with Parkinson's disease might develop treatment‐resistant axial dysfunction after bilateral subthalamic stimulation. Objectives To study whether lateralized stimulation (unilateral 50% amplitude reduction) for ≥21 days results in ≥0.13 m/s faster gait velocity in the dopaminergic ON state in these patients, and its effects on motor and axial function, quantitative gait and speech measures, quality of life, and selected cognitive tasks. Methods Randomized, double‐blinded, double‐crossover trial. Results In 22 participants (51–79 years old, 15 women), there were no significant changes in gait velocity, quality of life, cognitive, and speech measures. Reducing left‐sided amplitude resulted in a 2.5‐point improvement in axial motor Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS‐UPDRS) (P = 0.005, uncorrected) and a 1.9‐point improvement in the Freezing of Gait Questionnaire (P = 0.024, uncorrected). Conclusions Lateralized subthalamic stimulation does not result in meaningful improvement in gait velocity in patients with Parkinson's disease who develop treatment‐resistant axial dysfunction after bilateral subthalamic stimulation. Left subthalamic overstimulation may contribute to axial deterioration in these patients. © 2022 International Parkinson and Movement Disorder Society

Freezing of gait depends on cortico-subthalamic network recruitment following STN-DBS in PD patients

“…The published data are however contradictory up to now. In a recent randomized cross-over study, reducing left STN-DBS amplitude by 50% was found to decrease axial motor signs and FOG-Q, but no significant change was found when reducing the right STN-DBS amplitude [36]. In another randomized study, reducing stimulation amplitude by 30% contralateral to the least affected side had no positive effect with conversely an aggravation of symptoms, leading to a premature drop-out for 8/12 patients [37].…”

Optimal subthalamic stimulation sites and related networks for freezing of gait in Parkinson’s disease

“… 36 , 37 However, Lizárraga et al . 38 recently proposed that FOG-Q and axial motor signs are greatly associated with the left STN-DBS amplitude other than the right STN-DBS. No difference in post-operative FOG severity after the right and left STN-DBS has also been reported by other studies.…”