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

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.

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)