Multimodal Treatment for Hemiplegic Shoulder Pain

Hemiplegic shoulder pain (HSP) affects up to 60% of moderate to severely impaired stroke survivors. HSP is associated with poor rehabilitation outcomes, including interference with activities of daily living (ADLs) and poor quality of life (QoL). While many treatments for HSP have been proposed, most do not result in long-term relief of pain.

The investigators developed the use of intramuscular peripheral nerve stimulation (PNS) for the treatment of HSP, which involves the temporary placement of a percutaneous intramuscular electrode to stimulate the axillary nerve motor points to the deltoid muscle. A systematic review of randomized controlled trials (RCT) concluded that intramuscular PNS was the only treatment to provide long-term relief of pain for those with HSP. However, physical therapy (PT), which focuses on correcting biomechanics, is the most commonly prescribed treatment for HSP and is recommended by multiple practice guidelines. Prior to acceptance by the clinical community, the superiority of PNS to a course of PT must be demonstrated. The investigators completed a pilot RCT comparing PNS to PT and 67% vs. 25% of participants experienced successful pain relief (i.e., ≥ 2-pt or 30% reduction) from PNS and PT, respectively. Thus, the primary objective of this 2-site RCT is to confirm the findings of this preliminary pilot RCT. Combining PNS and PT, which may be how PNS is actually implemented in clinical practice, may have a synergistic therapeutic effect. Thus, the second objective of this RCT is to determine if multimodal treatment of HSP with PNS + PT is more efficacious for pain relief than PNS alone or PT alone. Mechanisms also will be explored.

Study Summary: This is a multi-site, placebo controlled, double-blinded RCT to confirm the superiority of PNS over PT in reducing HSP, and to determine if multimodal treatment of HSP with PNS + PT is more efficacious than PNS or PT alone. The standard of care for treating shoulder pain is to try several options, most commonly including medications, injections and therapy. Candidates considering this study likely have tried some treatments but without lasting success. Ninety-six participants will be randomized to receive PNS + PT, PNS + sham-PT, or sham-PNS + PT. The PNS + PT group will receive active PNS therapy for 6 hours per day for 3 weeks along with 8 sessions of PT to improve biomechanics of the affected shoulder. The PNS+ sham-PT group will receive active PNS therapy and sham-PT, consisting of placebo ultrasound, application of inert gel, lower limb strengthening, and walking exercises. The sham-PNS + PT group will receive a percutaneous lead in a similar manner as the active therapy groups, but with sham-stimulation, along with 8 sessions of PT. Measures of pain, pain interference with ADLs, QoL, shoulder biomechanics (shoulder abduction torque, shoulder kinematics, and Fugl-Meyer score), and measures of central sensitization (pain thresholds, secondary hyperalgesia, and temporal summation) will be assessed at baseline and at weeks 4 (end of treatment), 8, 12, 16, 20, 24, and 28.

Eligibility Criteria:
Inclusion Criteria:

* shoulder pain localized to the glenohumeral joint, subacromial area or deltoid insertion associated with: a) rest; b) passive abduction or external rotation range of motion (ROM); c) active abduction ROM; or, d) manual palpation;
* shoulder pain onset or worsening after the most recent stroke;
* weakness of shoulder abductors (≤4/5 on Medical Research Council (MRC) scale if isolated movement is present);
* ≥ 21-yrs old; \< 90-yrs old;
* time of stroke ≥ 3-mo;
* duration of HSP ≥3-mo;
* HSP with moderate to severe pain (BPI SF-3 ≥ 4);
* cognitive and communication ability to fulfill study requirements (cognitive ability based upon a score of ≥24 on the Mini Mental Status Exam (MMSE));
* availability of reliable adult who can assist with study procedures if necessary;
* willing and able to report shoulder pain and other conditions and complete study visits throughout the 4 month study period.

Exclusion Criteria:

* joint or overlying skin infection or history of recurrent skin infections;
* insensate skin;
* need to take \> 1 opioid and \> 1 nonopioid analgesic medication for HSP;
* regular intake of pain medications for another chronic pain;
* botox injection or subacromial steroid injections to the shoulder within the past 12 weeks;
* receiving occupational therapy (OT) or PT for HSP;
* bleeding disorder or international normalized ratio (INR) \> 3.0;
* sensitivity to skin surface electrodes and/or medical-grade adhesives, gels, tapes;
* medical instability;
* pregnancy;
* uncontrolled seizures (\>1/mo for 6-mo);
* history of cardiac arrhythmia with hemodynamic instability;
* history of lidocaine allergy;
* history of Parkinson's disease, spinal cord injury (SCI), traumatic brain injury (TBI), multiple sclerosis (MS), or ipsilateral upper extremity (UE) lower motor neuron lesion;
* history of complex regional pain syndrome, myofacial pain syndrome, other pain conditions (investigator discretion);
* cardiac pacemaker or other implanted electronic device;
* history of valvular heart disease (artificial valves, requiring antibiotics for procedures, etc.);
* severely impaired communication.