An Implantable Microneuromodulator for the Treatment of Chronic Shoulder Pain in Chronic Post-Stroke Subjects

Phase 2

Completed

Brief Summary: The goal of this research study is to investigate safety and gather initial effectiveness data for a new implanted device designed to treat chronic shoulder pain in chronic post-stroke subjects. The BBPM weighs less than 0.03 ounces and measures 1" x 0.1". It is implanted into the shoulder to stimulate the axillary nerve. Stimulation of this nerve may reduce shoulder pain, reduce shoulder subluxation, improve motion, improve function, and possibly decrease use of pain medication. CAUTION--Investigational device. Limited by Federal law to investigational use.

Detailed Description: This is a prospective, multi-center, randomized, controlled, double-blinded parallel study designed to evaluate feasibility and safety. The primary purpose of this study is to demonstrate the clinical feasibility of implanting the BBPM near a peripheral nerve for the treatment of chronic, intractable, pain in this case represented by chronic regional shoulder pain in hemiplegic stroke patients. This is a 48-week efficacy study with safety data collection throughout the study period and up to 2 years for all available subjects. Each study arm will receive therapeutic level stimulation for a total of 12 consecutive weeks (Weeks 1-12 for Active treatment group and Weeks 24-36 for the sham group) during the 48 weeks.

Recruitment & Eligibility

Inclusion Criteria

18 years of age or older
Chronic post-stroke duration greater than or equal to 6 months
Unilateral hemiplegic shoulder pain persisting for ≥6 months
Hemiparesis (shoulder abduction graded <5/5 on Manual Muscle Testing ipsilateral to the shoulder in which the subject has chronic pain
Shoulder pain ≥ 6/10 (on 0-10 numeric rating scale (NRS) for worst pain in last week (BPI #12))
Ability to give informed consent and understand study requirements
Ability to quantify pain using a 0-10 numeric rating scale. (A screening tool will be used to ensure that participants can rate 3 common pain scenarios (mosquito bite, stubbed toe and broken bone) on a 0-10 NRS relative to each other.)
Willing and able to understand and comply with all study-related procedures during the course of the study
Motivated to maintain an accurate diary for the study duration

Exclusion Criteria

Hemineglect (i.e., extinguish to double simultaneous stimulation)
Shoulder trauma or diagnosed shoulder pathology prior to stroke; history of any shoulder surgery, regardless of whether procedure preceded for followed stroke.
Need to take >1 pain medication (opioid or non-opioid) for shoulder pain
Regular use of pain medication for chronic pain other than shoulder pain
Anticoagulated (taking warfarin or heparin, including fractionated heparin) or has a bleeding disorder
Unable, per their prescribing physician, to stop antiplatelet medications (e.g., aspirin, ticlopidine (Ticlid), clopidogrel (Plavix), tirofiban (Aggrastat), and eptifibatide (Integrilin)) for at least 7 days prior to device implantation.
Cardiac pacemaker
Implanted neurostimulator (e.g., spinal cord, deep brain, vagus nerve) or implanted pump or infusion device
Prosthetic heart valve or valvular heart disease requiring antibiotic prophylaxis
History of cardiac arrhythmia with hemodynamic instability
Uncontrolled seizures (> 1 seizure per month)
Pregnant or plan on becoming pregnant during the study period
Medical instability
Currently require, or likely to require, diathermy
Currently require, or anticipated to require, MRI within 8 weeks of projected device implantation date
History of adverse reactions to local anesthetic (e.g., lidocaine)

Arm && Interventions

Group	Intervention	Description
Active BBPM stimulation	Battery Powered Microneuromodulator (BBPM)	Therapeutic Stimulation is applied via the Battery Powered Microneuromodulator (BBPM) which is programmed to deliver set stimulation parameters with approximate frequency of 30 Hz, current 5mA for 200 microseconds for the first 12 weeks of the study. The BBPM is implanted near the axillary nerve within the quadrilateral space.
Sham BBPM stimulation	Battery Powered Microneuromodulator (BBPM)	The Battery Powered Microneuromodulator is implanted near the axillary nerve within the quadrilateral space. The BBPM is programmed for the first 12 weeks of the study to deliver short bursts of extremely low amplitude electrical stimulation at very wide time intervals to give appearance, impression, and sensation of therapeutic treatment. After 24 weeks, the device will be reprogrammed to deliver therapeutic stimulation over a 12 week period.

Primary Outcome Measures

Name	Time	Method
Relief of Chronic Shoulder Pain	From baseline to 48 week follow up	Brief Pain Inventory (BPI) Question # 12 (rating pain at its worst in week prior to visit) was used to measure number of participants in whom BBPM provided any relief from chronic shoulder pain after implantation, as evidence by appropriate muscular contraction and/or paresthesia. BPI scale range is from 1 to 10, where 0 = 'no pain' and 10 = 'pain as bad as one can imagine'.

Secondary Outcome Measures

Name	Time	Method

Locations (3): Rancho Los Amigos National Rehabilitation Center
🇺🇸
Downey, California, United States
Virginia Mason Medical Center
🇺🇸
Seattle, Washington, United States
The Center for Pain Relief
🇺🇸
Charleston, West Virginia, United States