Phase II Subthalamic Nucleus (STN) vs. Globus Pallidus (GPi) Trial

US Department of Veterans Affairs299 enrolled

Overview

The goal of the second phase of the study is to determine if simultaneous bilateral subthalamic nucleus stimulation or simultaneous bilateral globus pallidus stimulation is more effective in reducing symptoms of Parkinson's Disease.

Deep Brain Stimulation (DBS) is a promising therapy for Parkinson's disease (PD) Whether DBS is superior to comprehensive best medical therapy or whether some patients or symptoms respond better to DBS in one area of the brain or the other is currently not known. The goals of this project are to compare the effectiveness of DBS and comprehensive medical therapy as treatments for PD (Phase I) and to compare bilateral DBS at 2 areas of the brain-the subthalamic nucleus (STN) and the globus pallidus (GPi) -to determine the most effective brain site for surgical intervention (Phase II) In this prospective, randomized, multi-center trial, 316 patients will be enrolled at 13 centers over four and a half years. Patients will initially be randomized to immediate surgery (DBS) or to 6 months of "best medical therapy". BMT arm patients will then be randomized to proceed into the DBS surgical phase of the trial. The DBS site (STN pr GPi) will be assigned on a random basis at the time the patient enters the surgical phase of the trial. Patients will be followed for two years post surgery (24 months for DBS only patients and 30 months for BMT-DBS patients) Effective 8/5/05 randomization to the BMT arm has been discontinued since the study has sufficient information to compare the outcomes of DBS and BMT patients at 6 months. The findings will be critically important in establishing the optimal surgical treatment of the disabling symptoms of PD.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Enrollment

299

Conditions

Parkinson's Disease

Interventions

Bilateral Deep Brain StimulationDEVICE

The DBS site (STN or GPi) was assigned on a random basis at the time the patient enters the surgical phase of the trial.

Eligibility

Sex: ALLMin age: 22 Years

Medical Language ↔ Plain English

Inclusion Criteria: * idiopathic Parkinson's Disease * Hoehn and Yahr stage 2 or worse when off medications * L-dopa responsive with clearly defined "on" periods (i.e. symptoms improve at least partially with L-dopa administration, a characteristic that helps distinguish idiopathic PD from "Parkinson's Plus" and atypical Parkinson's syndromes-see below) * persistent disabling symptoms (e.g. on troubling dyskinesias, or disabling "off" periods at least 3 hours/day) despite medication therapy. Patients will have been treated with variable doses of levodopa and dopamine agonists (at a minimum) and will have had an adequate trial of other adjunctive medications) * stable on medical therapy for at least one month prior to study enrollment * age \>21 * available and willing to be followed-up according to study protocol Exclusion Criteria: * "Parkinson's plus" syndromes, secondary, or atypical Parkinson's syndromes (e.g. progressive supranuclear palsy, striato-nigral degeneration, multiple system atrophy, post-stroke, post-traumatic, or post-encephalitic Parkinson's. These patients have cardinal symptoms characteristic of PD but with additional symptoms indicating other organic brain dysfunction, such as gaze palsies, autonomic dysfunction, lack of response to L-dopa, these individuals tend not to improve with standard treatments for PD) * previous Parkinson's Disease surgery * medical contraindications to surgery or stimulation (e.g. uncontrolled hypertension, advanced coronary artery disease, other implanted stimulation or electronically-controlled devices including cardiac demand pacemaker, aneurysm clips, cochlear implants, or a spinal cord stimulator) (Note: for the subject who receives either a pacemaker and/or defibrillator after this study enrollment, he/she will be allowed to continue the study if the neurostimulator system can be adequately programmed to permit system compatibility) * contraindication to magnetic resonance imaging (e.g. indwelling metal fragments or implants that might be affected by MRI) * active alcohol or drug abuse * score on Mini-Mental Status examination of 24 or lower, or other neuropsychological dysfunction 9e.g. dementia) that would contraindicate surgery * intracranial abnormalities that would contraindicate surgery (e.g. stroke, tumor, vascular abnormality affecting the target area) * pregnancy * concurrent participation in another research protocol

Locations (14)

University of California at Los Angeles

Los Angeles, California, United States

University of California at San Francisco

San Francisco, California, United States

Outcomes

Primary Outcomes

The Change From Baseline in the UPDRS-III Score at 24 Months With Deep-brain Stimulation and Without Medication.

The primary outcome measure for the comparison of GPi deep brain stimulation (DBS) to STN DBS is the motor function score of the Unified Parkinson's Disease Rating Scale (UPDRS Part III) measured while the patient is off medications and on stimulation at follow-up visits post surgery. UPDRS Part III has 14 items assessing motor skills including facial expression and speech, tremors, rigidity, posture, gait, and bradykinesia. Left and right sides (arms, legs, and hands) are assessed separately for seven of the functions. The motor function (UPDRS part III) assessments are done by turning on the stimulation with and without taking PD medications (on/off) at each in-person visit. A summary score ranging from 0 to 108 is generated by adding the 14 specific motor function responses. The higher score indicates the worse motor function.

Time frame: Baseline and 24 months

Secondary Outcomes

The Change From Baseline in the UPDRS Scores Part I (Mentation) at 24 Months.

The UPDRS has four parts (Parts I-IV) in which a total of 42 disease characteristics are assessed. Most characteristics are assessed according to their severity on a 0-4 scale (0 = normal, 4 = most substantial impairment), and some are assessed only for absence (score = 0) or presence (score = 1). Part I has four items assessing intellectual impairment, thought disorder, depression and motivation. A summary score ranging from 0 to16 is generated by adding the four items. The higher score indicates worse condition.

Time frame: Baseline and 24 months

The Change From Baseline in the UPDRS Scores Part II (Activity of Daily Living) at 24 Months.

The UPDRS has four parts (Parts I-IV) in which a total of 42 disease characteristics are assessed. Most characteristics are assessed according to their severity on a 0-4 scale (0 = normal, 4 = most substantial impairment), and some are assessed only for absence (score = 0) or presence (score = 1). Part II has 13 items focusing on activities of daily living including walking, writing, dressing and speech. A summary score ranging from 0 to 52 is generated by adding the 13 items. The higher score indicates worse condition.

Data from ClinicalTrials.gov

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