Directional PSA Versus STN DBS for TD-PD

Directional Deep Brain Stimulation of the Posterior Subthalamic Area (PSA) Versus Subthalamic Nucleus (STN) for Tremor-dominant Parkinson's Disease: a Prospective, Randomized, Double-blinded, Cross-over Trial

The aim of this study is to compare the effectiveness of the deep brain stimulation in the posterior subthalamic area (PSA) versus the subthalamic nucleus (STN) using directional lead for the treatment of tremor-dominant Parkinson's disease (PD) in a randomized, double-blinded, cross-over manner.

Study Overview

• Status: Recruiting
• Conditions: Parkinsons Disease (PD)
• Intervention / Treatment: Device: directional Deep brain stimulation

Detailed Description

This single-center trial utilizes directional deep brain stimulation (DBS) current-steering technology to compare the clinical efficacy and tolerability of the posterior subthalamic area (PSA) versus the subthalamic nucleus (STN) for the treatment of tremor-dominant Parkinson's disease (TD-PD) within the same subject. The study is optimized into a two-phase framework to maximize patient safety and protocol compliance:

Phase 1: Two-month post-implantation, acute mapping is conducted to define the therapeutic window for PSA and STN configurations in a blinded randomized order. If a configuration induces immediate, unmanageable adverse events before reaching efficacy, it is classified as "intolerant" and excluded from that participant's subsequent chronic phase.

Phase 2 (Chronic Crossover): Participants with tolerated configurations are entered into a chronic randomized phase with a blinded sequence of 2-month PSA or STN chronic stimulation. Following the core two-arm crossover, all eligible patients transition into an open-label, exploratory sequential add-on phase of 2-month with combined PSA+STN stimulation to evaluate potential synergistic benefits.

All participants will then be followed-up up to 12 months after surgery.

• Study Type: Interventional
• Enrollment (Estimated): 32
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Dianyou Li, MD, PhD; Phone Number: +0086-021-64370045; Email: ldy11483@rjh.com.cn

Study Locations

• China
  • Shanghai, China, 200025
    • Recruiting
    • Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine
    • Contact: Dianyou Li, MD, PhD; Phone Number: +0086-021-64370045; Email: ldy11483@rjh.com.cn

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• diagnosis of idiopathic Parkinson's disease
• tremor-dominant subtype in the off-medication condition
• modified Hoehn-Yahr scale of 2 to 4 in the off-medication condition
• receiving regular anti-parkinsonian drugs for more than 6 weeks
• good compliance and written informed consent provided

Exclusion Criteria:

• Atypical parkinsonism
• History of stroke, encephalitis, neuroleptic uses, MRI scan with evidence of significant brain atrophy, lacunar infracts, or other conditions that might interfere with the intracranial surgery
• Presence of cognitive, or psychiatric or other co-morbidities (e.g., dementia, epilepsy, cranial traumatism, brain tumor, schizophrenia, severe depression or bipolar disorder, personality disorder, etc.) that might interfere with the patient's ability to complete the evaluations or to provide informed consent
• Presence of anatomical abnormalities in the target region
• Clinically significant medical history that would increase pre-/post-operative complications
• Other conditions considered by the investigators that might interfere with the surgery procedure, the follow-ups, and the interpretation of the data

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: directional PSA-STN; Participants randomized in this arm will receive the bilateral directional PSA stimulation and then will be crossovered to the bilateral directional STN stimulation in the acute mapping phase (phase I). After that, participants will receive the bilateral directional PSA stimulation in the first two months in the chronic randomized phase (phase II) and then will be crossovered to the bilateral directional STN stimulation for another two months.	Device: directional Deep brain stimulation; active directional DBS with optimal stimulating parameters
Experimental: directional STN-PSA; Participants randomized in this arm will receive the bilateral directional STN stimulation and then will be crossovered to the bilateral directional PSA stimulation in the acute mapping phase (phase I). After that, participants will receive the bilateral directional STN stimulation in the first two months in the chronic randomized phase (phase II) and then will be crossovered to the bilateral directional PSA stimulation for another two months.	Device: directional Deep brain stimulation; active directional DBS with optimal stimulating parameters

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from Baseline in Movement Disorder Society-sponsord Unified Parkinson's Disease Rating Scale Part III tremor subscore Between PSA and STN Stimulation in the chronic randomized phase	The tremor subscore is derived from the sum of items 3.15 to 3.18 of the MDS-UPDRS-III. This measure directly compares the within-subject efficacy of directional PSA stimulation versus directional STN stimulation in the chronic cross-over phase. Lower scores indicate greater tremor suppression.	Baseline (pre-operation, OFF-medication) and the end of each 2-month stimulation period (Month 4 and Month 6)

Secondary Outcome Measures

Outcome Measure	Time Frame
Change from Baseline in Fahn-Tolosa-Marin Clinical Rating Scale Between PSA and STN Stimulation in the chronic randomized phase	Baseline (pre-operation, OFF-medication) and the end of each 2-month stimulation period (Month 4 and Month 6)
Change from Baseline in Movement Disorder Society-sponsord Unified Parkinson's Disease Rating Scale Part III total score Between PSA and STN Stimulation in the chronic randomized phase	Baseline (pre-operation, OFF-medication) and the end of each 2-month stimulation period (Month 4 and Month 6)
Change from Baseline in Berg Balance Scale score Between PSA and STN Stimulation in the chronic randomized phase	Baseline (pre-operation, OFF-medication) and the end of each 2-month stimulation period (Month 4 and Month 6)
Change from Baseline in 39-item Parkinsons disease questionnaire Between PSA and STN Stimulation in the chronic randomized phase	Baseline (pre-operation) and the end of each 2-month stimulation period (Month 4 and Month 6)
Proportion of Participants with Acute Phase Intolerance to Single-Target Stimulation	Up to 2 months after sugery
Adverse events	Up to 12 months after surgery

Other Outcome Measures

Outcome Measure	Time Frame
Change from Baseline in Beck Depression Inventory-II Between PSA and STN Stimulation in the chronic randomized phase	Baseline (pre-operation, OFF-medication) and the end of each 2-month stimulation period (Month 4 and Month 6)
Change from Baseline in Beck Anxiety Inventory Between PSA and STN Stimulation in the chronic randomized phase	Baseline (pre-operation, OFF-medication) and the end of each 2-month stimulation period (Month 4 and Month 6)
Change from Baseline in nonmotor symptoms scale for Parkinson's disease (NMSS) Between PSA and STN Stimulation in the chronic randomized phase	Baseline (pre-operation, OFF-medication) and the end of each 2-month stimulation period (Month 4 and Month 6)
Change from Baseline in Mini-Mental State Examination Between PSA and STN Stimulation in the chronic randomized phase	Baseline (pre-operation, OFF-medication) and the end of each 2-month stimulation period (Month 4 and Month 6)
Change from Baseline in levodopa equivalent daily dose Between PSA and STN Stimulation in the chronic randomized phase	Baseline (pre-operation, OFF-medication) and the end of each 2-month stimulation period (Month 4 and Month 6)
Change from Baseline in total electrical energy delivered Between PSA and STN Stimulation in the chronic randomized phase	Baseline (pre-operation, OFF-medication) and the end of each 2-month stimulation period (Month 4 and Month 6)

Collaborators and Investigators

• Sponsor: Ruijin Hospital

Study record dates

Study Major Dates

• Study Start (Actual): July 1, 2026
• Primary Completion (Estimated): December 1, 2028
• Study Completion (Estimated): June 1, 2029

Study Registration Dates

• First Submitted: July 7, 2026
• First Submitted That Met QC Criteria: July 7, 2026
• First Posted (Actual): July 14, 2026

Study Record Updates

• Last Update Posted (Actual): July 14, 2026
• Last Update Submitted That Met QC Criteria: July 7, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: subthalamic nucleus; tremor-dominant Parkinson's disease; posterior subthalamic area; directional deep brain stimulation
• Additional Relevant MeSH Terms: Synucleinopathies; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Neurodegenerative Diseases; Movement Disorders; Parkinsonian Disorders; Basal Ganglia Diseases; Parkinson Disease
• Other Study ID Numbers: dPSA-STNforTD-PD

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: Yes