Randomized, double-blind, crossover design, interventional study to assess the differences between mixed cathodic/anodic, pure cathodic, and pure anodic stimulation with respect to efficacy, side effect thresholds, symptom control, and quality of life in Parkinson's Disease patients implanted with Boston Scientific Cartesia directional DBS leads in the bilateral STN.
Prior studies and literature have suggested that directional leads might enable the use of complex bipolar configurations to activate neurons within a target and avoid side effects based on knowledge of local fiber tracts. The Boston Scientific Vercise system offers a unique opportunity to test this hypothesis. The Cartesia lead is a directional lead with 4 levels of contact, the middle 2 which are segmented, while the Vercise Genus generators utilize multiple independent current sources connected to each contact. This combination enables complex, highly customizable stimulation configurations, which can be incrementally adjusted in real time, without recourse to shutting the device off between parameter changes. This study proposes to utilize this technology to compare pure cathodic, pure anodic, and mixed cathodic/anodic stimulation in patients with Parkinson's Disease implanted with STN-DBS leads. The primary objective is to assess the differences between mixed cathodic/anodic, pure cathodic, and pure anodic stimulation with respect to efficacy, side effect thresholds, minimum current amplitude that activates side effects inducing the pyramidal tract, symptom control, and quality of life in Parkinson's Disease (PD) patients implanted with Boston Scientific Cartesia directional DBS leads in the bilateral STN.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
SUPPORTIVE_CARE
Masking
DOUBLE
Enrollment
20
Mixed cathodic/anodic stimulation setting on the Boston Scientific Vercise DBS system.
Pure cathodic stimulation setting on the Boston Scientific Vercise DBS system.
Pure anodic stimulation setting on the Boston Scientific Vercise DBS system.
USF Health STC Department of Neurosurgery and Tampa General Hospital
Tampa, Florida, United States
Parkinson's Disease Questionnaire-39 (PDQ-39)
Patient's preferred stimulation parameter setting (with or without anodic stimulation) determined by their responses to the questionnaire and patient's stated preference. The score ranges from 0-100, with lower scores reflecting better quality of life of patients.
Time frame: At the end of patient's participation in the study, 3 months.
Unified Parkinson's Disease Rating Scale (UPDRS) Part III Motor Scores
Change in UPDRS part III motor scores obtained ON stimulation/OFF medications at 4 weeks on each parameter setting relative to UPDRS part III motor scores obtained OFF stimulation/OFF medications at baseline. Scores range from 0-132. 0 indicates no motor impairment, 32 or below is considered mild impairment, and a score of 59 and above indicates severe impairment.
Time frame: Baseline and 4 weeks after each parameter setting.
Unified Parkinson's Disease Rating Scale (UPDRS) Part III Motor Sub-scores
Change in UPDRS part III motor sub-scores (tremor, rigidity, bradykinesia, postural stability/gait) obtained ON stimulation/OFF medications at 4 weeks on each parameter setting relative to UPDRS part III motor scores obtained OFF stimulation/OFF medications at baseline. 8 sub-scores for each section of the scale. Each sub-section is scored from 0-4, or a score of 8 if "untestable". A score of 0 in each sub-section or a lower score normal or absence of symptom.
Time frame: Baseline and 4 weeks after each parameter setting.
Clinical Global Impression- Positive Symptoms (CGI-P) Scores Mixed Cathodic/Anodic
CGI-P at 4 weeks following mixed cathodic/anodic stimulation. The scale uses a 7-point severity scale with 1 indicating normal or no positive symptoms and 7 indicating most severely ill patients with positive symptoms. Each item is rated independently on the 7-point scale.
Time frame: 4 weeks following mixed cathodic/anodic stimulation.
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Clinical Global Impression- Positive Symptoms (CGI-P) Scores Pure Cathodic
CGI-P scores at 4 weeks following pure cathodic stimulation. The scale uses a 7-point severity scale with 1 indicating normal or no positive symptoms and 7 indicating most severely ill patients with positive symptoms. Each item is rated independently on the 7-point scale.
Time frame: 4 weeks following pure cathodic stimulation.
Clinical Global Impression- Positive Symptoms (CGI-P) Scores Pure Anodic
CGI-P scores at 4 weeks following pure anodic stimulation. The scale uses a 7-point severity scale with 1 indicating normal or no positive symptoms and 7 indicating most severely ill patients with positive symptoms. Each item is rated independently on the 7-point scale.
Time frame: 4 weeks following pure anodic stimulation.
Patient Global Impression of Change (PGI-C) Scores Mixed Cathodic/Anodic
PGI-C scores at 4 weeks following mixed cathodic/anodic stimulation. The scale uses a 7-point Likert scale for scoring. Scores of 1 and 2 indicate significant improvement, score of 4 indicates no change in patient's status, and scores of 5 or higher indicate worsening or deteriorating changes in patient.
Time frame: 4 weeks following mixed cathodic/anodic stimulation.
Patient Global Impression of Change (PGI-C) Scores Pure Cathodic
PGI-C scores at 4 weeks following pure cathodic stimulation. The scale uses a 7-point Likert scale for scoring. Scores of 1 and 2 indicate significant improvement, score of 4 indicates no change in patient's status, and scores of 5 or higher indicate worsening or deteriorating changes in patient.
Time frame: 4 weeks following pure cathodic stimulation.
Patient Global Impression of Change (PGI-C) Scores Pure Anodic
PGI-C scores at 4 weeks following pure anodic stimulation. The scale uses a 7-point Likert scale for scoring. Scores of 1 and 2 indicate significant improvement, score of 4 indicates no change in patient's status, and scores of 5 or higher indicate worsening or deteriorating changes in patient.
Time frame: 4 weeks following pure anodic stimulation.
Threshold for Clinical Benefit During Deep Brain Stimulation Programming
Minimum stimulation amplitude required to achieve a predefined clinical benefit at each stimulation parameter setting, including mixed cathodic/anodic stimulation, pure cathodic stimulation, and pure anodic stimulation. Clinical benefit will be determined based on investigator assessment of motor symptom improvement during stimulation programming. The unit of measure is "Stimulation amplitude (mA)".
Time frame: Throughout the patient's participation in the study, 3 months.
Threshold for Stimulation-Related Adverse Effects During Deep Brain Stimulation Programming
Minimum stimulation amplitude at which a stimulation-related adverse effect is first observed or reported during programming at each stimulation parameter setting, including mixed cathodic/anodic stimulation, pure cathodic stimulation, and pure anodic stimulation. Adverse effects will be identified through participant report and investigator assessment during systematic amplitude titration. Unit of Measure: "Stimulation amplitude (mA)".
Time frame: Throughout the patient's participation in the study, 3 months.
Model of the Volume of Tissue Activated (VTA)
Model of the VTA resulting from each stimulation parameter setting compared with respect to the regional anatomy as derived from patient-specific segmentation of pre-operative MRI and post-operative/post-enrollment CT studies. Relative location, extent, and spread out of the boundaries of the Subthalamic Nucleus (STN) of VTAs obtained with all stimulation parameter settings.
Time frame: Baseline and 4 weeks after each parameter setting.