Background: Stimulation of a specific site in the dorsolateral subthalamic nucleus (STN) was recently associated with slower motor progression in Parkinson's Disease (PD) [1], based on data from the deep brain stimulation (DBS) in early-stage PD pilot trial [2]. This study's objective was to test whether stimulation of this site is also associated with optimal improvements of long-term motor symptoms in advanced-stage PD.

Sunday, April 18April 13, 2021Free AccessLong-Term Evaluation of Deep Brain Stimulation for Treatment of Parkinson’s Disease Using a Multiple-Source, Constant-Current Rechargeable System: 4-year Follow-Up of a Prospective, Double-Blind RCT (1404)Jerrold Vitek, Roshini Jain, and Lilly Chen INTREPID Clinical Study Group, and Philip StarrAuthors Info & AffiliationsApril 13, 2021 issue96 (15_supplement)https://doi.org/10.1212/WNL.96.15_supplement.1404 Letters to the Editor

Objective: An aging population has led to an increasing prevalence of neurodegenerative diseases, creating a need for additional movement disorders trained neurologists. Focus on Common Movement Disorders (FOCMD), an annual, two-day educational course hosted by Vanderbilt University Medical Center, has trained 639 neurology residents from 107 programs over the past 13 years. The course's goal is to inspire neurology residents to pursue fellowship training in movement disorders.

Introduction: DBS improves motor outcomes and quality of life in patients with movement disorders, including Parkinson's disease, disabling tremor, and dystonia. Several factors may affect DBS outcomes within and across geographies, including the surgical procedure, novel features, and patient management practices. There is increasing interest in tracking long-term outcomes to provide ongoing market surveillance, to establish best practices, and to identify opportunities for therapy unmet needs.

Background: Thalamic ventral intermediate nucleus (VIM) deep brain stimulation (DBS) is an effective therapy for medication-refractory essential tremor (ET). However, 13–40% of patients with an initially robust tremor efficacy lose this benefit over time despite reprogramming attempts. At our institution, a cohort of ET patients with VIM DBS underwent implantation of a second anterior (ventralis oralis anterior; VOA) DBS lead to permit “confined stimulation.” We sought to assess whether confined stimulation conferred additional tremor capture compared to VIM or VOA stimulation alone. Methods: Seven patients participated in a protocol-based programming session during which a video-recorded Fahn-Tolosa-Marin Part A (FTM-A) tremor rating scale was used in the following 4 DBS states: off stimulation, VIM stimulation alone, VOA stimulation alone, and dual lead (confined) stimulation. Results: The average (SD) baseline FTM-A off score was 17.6 (4.0). VIM stimulation alone lowered the average FTM-A total score to 6.9 (4.0). Confined stimulation further attenuated the tremor, reducing the total score to 5.7 (2.8). Conclusions: Confined thalamic DBS can provide additional symptomatic benefits in patients with unsatisfactory tremor control from VIM or VOA stimulation alone.

Frontal-basal ganglia circuitry dysfunction caused by Parkinson's disease impairs important executive cognitive processes, such as the ability to inhibit impulsive action tendencies. Subthalamic Nucleus Deep Brain Stimulation in Parkinson's disease improves the reactive inhibition of impulsive actions that interfere with goal-directed behavior. An unresolved question is whether this effect depends on stimulation of a particular Subthalamic Nucleus subregion. The current study aimed to 1) replicate previous findings and additionally investigate the effect of chronic versus acute Subthalamic Nucleus stimulation on inhibitory control in Parkinson's disease patients off dopaminergic medication 2) test whether stimulating Subthalamic Nucleus subregions differentially modulate proactive response control and the proficiency of reactive inhibitory control. In the first experiment, twelve Parkinson's disease patients completed three sessions of the Simon task, Off Deep brain stimulation and medication, on acute Deep Brain Stimulation and on chronic Deep Brain Stimulation. Experiment 2 consisted of 11 Parkinson's disease patients with Subthalamic Nucleus Deep Brain Stimulation (off medication) who completed two testing sessions involving of a Simon task either with stimulation of the dorsal or the ventral contact in the Subthalamic Nucleus. Our findings show that Deep Brain Stimulation improves reactive inhibitory control, regardless of medication and regardless of whether it concerns chronic or acute Subthalamic Nucleus stimulation. More importantly, selective stimulation of dorsal and ventral subregions of the Subthalamic Nucleus indicates that especially the dorsal Subthalamic Nucleus circuitries are crucial for modulating the reactive inhibitory control of motor actions.

Tremor is the most common movement disorder. Medical management is first-line treatment, but when ineffective patients have limited options other than surgical thalamotomy (ST) or deep brain stimulator placement (DBS). Stereotactic radiation to the ventral intermediate nucleus (VIM) of the thalamus is a standard treatment alternative to surgical option. We hypothesized that Linac-based stereotactic radiosurgery (SRS) would provide effective tremor control and improve quality of life on this prospective, observational study.

Introduction: Post-operative programming of deep brain stimulation for movement disorders can be both time consuming and difficult, which can delay the optimal symptom control for the patient. Probabilistic maps of stimulation response could improve programming efficiency and optimization.Methods: The clinically selected contacts of patients who had undergone ventral intermediate nucleus deep brain stimulation for the treatment of essential tremor at our institution were compared against contacts selected based on a probability map of symptom reduction built by populating data from a number of patients using non-rigid image registration. A subgroup of patients whose clinical contacts did not match the map-based selections prospectively underwent a tremor rating scale evaluation to compare the symptom relief achieved by the two options. Both the patient and video reviewer were blinded to the selection.Results: 54% of the map-based and clinical contacts were an exact match retrospectively and were within one contact 83% of the time. In 5 of the 8 mismatched leads that were evaluated prospectively in a double blind fashion, the map-based contact showed equivalent or better tremor improvement than the clinically active contact.Conclusions: This study suggests that probability maps of stimulation responses can assist in selecting the clinically optimal contact and increase the efficiency of programming. (C) 2014 Elsevier Ltd. All rights reserved.