Treatment of Shoulder Subluxation in Chronic Stroke Patients
Condition: Shoulder Dislocation
MeSH terms: Shoulder Dislocation
Study type: Interventional
Phase: Phase 1

Summary: 
      The study looks at treatments for reversing chronic shoulder subluxation after a stroke. It
      compares electrical stimulation with surface electrodes (stimulation through the skin) with
      intra-muscular stimulation (from inside the muscle)using an implanted micro-stimulator
      (BION). Subjects are put either in a surface stimulation or a BION® group. In the BION®
      group, two BION®s are implanted in the shoulder, the medial deltoid and supraspinatus
      muscles. Treatment consists of a baseline of 6 weeks, and 6 weeks of therapy, consisting of 2
      sessions per day for 10 to 30 minutes each time. This is followed by 6 weeks without therapy.
      If testing shows that after 6 weeks of therapy there is no reversal of subluxation, more
      intense therapy is carried out for another 6 weeks. Treatment is similar in the surface
      electrode group, but surface electrodes deliver the stimulation instead of BION®s. A total of
      30 subjects is expected to complete the study.
    

Detailed description: 
      The BION™ is a novel implantable neuromuscular stimulator whose intended use in this study is
      to reanimate the shoulder muscles of stroke survivors with shoulder subluxation. Strokes are
      considered to be the most important cause of adult disability in North America, with 500,000
      new cases per year in the U.S. (National Stroke Association) and 45,000 in Canada
      (Langton-Hewer, 1990; Shuaib & Hachinski, 1991). Three-quarters of these patients survive and
      half of the survivors have substantial muscle weakness after 6 months (Gresham et al., 1979)
      with little chance of spontaneous recovery (Anderson, 1990; Bonita & Beaglehole, 1988). The
      most commonly affected region in the early phases of recovery is the shoulder; 80% of
      hemiplegic stroke patients suffer from shoulder subluxation and associated chronic pain
      (Smith et al., 1980). The shoulder muscles that are normally active tonically are flaccidly
      paralyzed; the weight of the pendant arm gradually stretches and damages the atrophic muscles
      and ligaments, allowing the head of the humerus to descend out of the glenoid fossa. This
      results in chronic shoulder pain that is difficult to treat and tends to obstruct physical
      therapy directed toward regaining some use of the paretic arm. Our hypothesis is that
      electrical stimulation delivered by the BIONs should be fundamentally equivalent to muscle
      activation achieved voluntarily or by transcutaneous electrical nerve stimulation (TENS), but
      that the BIONs will prove to be a more clinically acceptable and effective approach. The BION
      system consists of the BION implants themselves, a controller that is operated by the study
      participant, and fitting hardware and software used by the clinician to implant, test, and
      program BION function.

      In this study, the BION will be used to reanimate the shoulder muscles of stroke survivors
      experiencing shoulder subluxation. The objective of this study is to evaluate the safety and
      efficacy of intramuscular stimulation of BIONs to correct established, symptomatic shoulder
      subluxation in chronic stroke survivors. The results of intramuscular stimulation by BIONs
      will be compared with the results of treatment with conventional therapy: surface
      stimulation.

      Degree of shoulder subluxation will be the primary outcome measure for the study. We have
      included other (secondary) outcome measures (i.e., muscle strength, range of motion,
      functional activity, spasticity/tone, subject satisfaction and pain) which may reveal
      secondary benefits of treatment with BIONs. The investigation is expected to last up to 21
      weeks for each study participant. The study will be completed over a 5-year period.
    

Intervention name(s): BION stimulation
Intervention type(s): Device
Intervention description(s): The study will have two phases, each with a six week duration. During phase 1, the BION group will be implanted with BIONs in the middle deltoid and supraspinatus muscles. The muscles will be stimulated electrically by way of the BION and an external controller for one to two hours per day at 5pps in an on-off duty cycle train. The SE group will begin surface stimulation similar to that of BE group.
Subjects in either group whose initial therapy in phase 1 successfully reduces the amount of shoulder subluxation to 5mm or less will go off stimulation for six weeks, and be reassessed whether subluxation is redeveloping.
If a subject in either group does not respond sufficiently to phase 1 therapy, the participant will move to phase 2 where the shoulder will be stimulated at up to 25 pps either with surface stimulation (SE group) or BION stimulation (BE group) for another six weeks. At the end of phase 2, participants will go off stimulation for six weeks and then be reevaluated.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Neuromuscular stimulator; Shoulder subluxation