Perioperative Mirror Therapy and Phantom Limb Pain

Overview

Mirror therapy will consist of observing the unaffected limb reflected in a mirror positioned in the midline to block the view of the affected limb. All therapy sessions will be supervised by a physical therapist with the exception of weekends when the patients will continue therapy on an independent basis. In an effort to objectively demonstrate cortical reorganization associated with mirror therapy, patients can elect to participate in a functional MRI (fMRI) portion of the study. The fMRI would be evaluated prior to initiating the experimental or control therapy (Due to the sensitive timeline in this population and its effect on recruitment, we have amended the protocol to allow recruitment and enrollment to take place even if the timeline does not allow for the fMRI to be executed 2 weeks prior to amputation. Though this would be ideal, we will accept subjects that are only available for day before amputation scans), just before the operative procedure, at four weeks post-operation and then again at one year. All subjects will be evaluated at 4 weeks, 8 weeks (functional physical therapy (PT) tests only) 12 weeks, and 12 months postoperatively to determine 1) the incidence, severity and functional impact of phantom limb pain 2)the ability to meet various specialists' endpoints, to include participation in physical therapy, and 3) overall quality of life which the patients can describe subjectively. This therapy could have a dramatic impact on the long term prognosis of amputees whether due to trauma, metabolic conditions, tumor, or peripheral vascular disease. This protocol will include performing fMRIs on a cohort of healthy, active duty, age matched, male personnel to create reference data to compare the fMRI data of study participants.

Subjects scheduled for amputation will be randomized to either receive perioperative plasma ball (sham) or mirror therapy, which involves a daily session of 30 minutes of performing physical therapy exercises using either a mirror or plasma ball under the supervision of a certified physical therapist. Subjects scheduled to undergo limb amputation who opt in for the fMRI portion of the study will undergo a pre-treatment baseline fMRI (2 weeks prior to scheduled amputation, if possible, but as late as 1 day pre-operative), a post-mirror or sham therapy (preoperative-day before) fMRI, post-operative fMRI at 4 weeks and one year. Performing a baseline fMRI prior to any treatment, will provide objective data regarding the location and extent of cortical involvement prior to initiating mirror therapy. Those subjects randomized to the mirror therapy limb will undergo 14 days of daily mirror therapy sessions preoperatively which will consist of observing the unaffected limb reflected for 30 minutes in a mirror positioned in the midline to block the view of the affected limb. Those randomized to standard therapy will participate in an equivalent period of time undergoing a sham therapy with a 22" plasma globe involving contralateral limb interaction with the sphere. All therapy sessions will be supervised by a physical therapist with the exception of weekends when the patients will continue therapy on an independent basis. The subjects will then undergo a repeat fMRI (or first baseline, depending if pre-operative fMRI was possible) after completion of preoperative mirror or sham therapies and prior to surgical amputation to evaluate for changes suggestive of mirror therapy induced normalization in cortical patterns. Control subject group will undergo 3 questionnaires and one functional fMRI exam. Imaging protocol will be identical to preoperative imaging protocol for amputation subjects. This data will aid in establishing baseline fMR activation values for all fMR paradigms tested. The control group will not be randomized to receive either perioperative plasma ball (sham) or mirror therapy. All Subjects scheduled for surgery will then undergo amputation under the anesthetic technique of provider choice. If regional/neuraxial anesthetic techniques are used they will be standardized up to 1 day preoperative and 3 days postoperative. If using dexmedetomidine and/or ketamine infusions, their use will be limit to intraoperative periods at doses of 0.2 mcg/kg/hr and 0.15mg/kg/hr limit respectively. Anesthesiologist/Anesthetist choice will be permitted for all other intraoperative and postoperative meds. Within 1 week of amputation subjects will again repeat 14 days of their respectively assigned therapy limbs as described above in addition to routine post amputation care. All subjects will then be evaluated at four weeks postoperatively with measures delineated in section 5.(Statistics) to determine 1) incidence and severity of phantom limb pain 2) participation in therapy and ability to meet functional endpoints 3) quality of life. These same measures will be assessed at 12 weeks (3 months) and again at one year post procedure. A repeat fMRI will be obtained in those Subjects participating in the fMRI limb in order to evaluate how the postoperative cortical mapping compares to prior preoperative and postoperative studies.