Electrical Stimulation for Hemiplegic Shoulder Pain

Post-stroke shoulder pain is a major rehabilitation problem affecting moderate to severely impaired stroke survivors. Surface electrical stimulation (ES) of muscles surrounding the hemiparetic shoulder has been demonstrated to be beneficial, but despite the evidence for therapeutic benefit, the clinical implementation of surface ES for poststroke shoulder pain has been difficult. In order to address the limitations of surface ES, the investigative team pioneered the development of percutaneous intramuscular (IM) ES for the treatment of post-stroke shoulder pain. However, prior to acceptance by the clinical community, additional gaps in the scientific and clinical knowledge need to be addressed. This study begins to do so. The primary objective is to estimate the relative pain reduction associated with IM ES vs. "usual care." We hypothesize that the IM ES group will exhibit a larger effect size with respect to pain reduction compared to "usual care". A secondary objective is to estimate the effect on health related QOL of IM ES vs. "usual care." Demonstration of improvement in QOL will validate the clinical relevance of the intervention. We hypothesize that the IM ES group will exhibit greater improvement in health related QOL compared to "usual care".


Eligibility Criteria:
Inclusion Criteria:

* shoulder pain localized to the glenohumeral joint, subacromial area or deltoid insertion associated with any of the following conditions: a) rest; b) passive abduction or external rotation ROM; c) active abduction or external rotation ROM; or d) manual palpation
* weakness of shoulder abductors (≤4/5 on MRC if isolated movement is present)
* age ≥21-yrs
* time from stroke ≥ 3-mo
* shoulder pain onset after the most recent stroke
* duration of shoulder pain ≥ 3-mo
* severity of shoulder pain on BPI-SF 3 ≥4
* cognitive ability to fulfill study requirements \[a) exhibit 3 object immediate and 30 minute recall; b) ability to use a numeric rating scale (using a 0-10 numeric rating scale) by correctly ranking the tightness they feel on the unaffected arm of 3 low-pressure inflations with a standard sphygmomanometer cuff which follow a predetermined sequence (20, 40 and 0 mm Hg); and c) ability to follow 3-stage commands\]
* availability of a reliable adult who can check the skin and assist the participant with the treatment protocol
* willing and able to report severity of shoulder pain throughout the study period
* willing to make all scheduled study visits post-implantation.

Exclusion Criteria:

* evidence of joint or overlying skin infection
* insensate skin
* \>1 opioid or nonopioid analgesics daily for shoulder pain
* daily intake of pain medications for any other chronic pain
* intra-articular or subacromial steroid injections to the shoulder in the previous 12-wks
* botulinum toxin injection to the trapezius, pectoralis or subscapularis muscle in the previous 12-wks
* receiving physical or occupational therapies for shoulder pain
* physician-diagnosed shoulder pathology symptomatic within the 5 yrs prior to CVA
* bleeding disorder
* INR\>3.0 for those on warfarin \[INR\>3.0\]
* poorly controlled diabetes \[HbA1c\>7.0\]
* medical instability
* pregnancy
* uncontrolled seizures (\>1/mo for 6-mo)
* uncompensated hemi-neglect
* severely impaired communication
* moderate to severe depression
* other confounding conditions such as ipsilateral upper limb lower motorneuron lesion, Parkinson's Disease, spinal cord injury, traumatic brain injury or multiple sclerosis
* other medical issues such as complex regional pain syndrome, bicipital tendonitis, myofacial pain syndrome, etc.
* the following cardiac conditions: a) history of arrhythmia with hemodynamic instability, such as ventricular tachycardia, supraventricular tachycardia and rapid ventricular response atrial fibrillation; b) any implantable stimulator such as demand pacemakers or defibrillators; and c) valvular heart disease including artificial valves (due to risk of infection and endocarditis)
* likely non-compliance factors such as distance from the center, inadequate social support, or psychiatric/psychologic factors