Mirror Therapy for Phantom Limb Pain
Condition: Amputation
MeSH terms: Phantom Limb
Study type: Observational

Summary: 
      This study, conducted at the National Institutes of Health (NIH) and at Walter Reed Army
      Medical Center (WRAMC), will explore the phenomenon of phantom limb pain (a continued feeling
      of pain in an amputated limb) and will use functional magnetic resonance imaging (fMRI) to
      investigate the effect of mirror therapy on phantom limb pain.

      Right-handed people between 18 and 75 years of age who are in the WRAMC Military Amputee
      Research Program and healthy control subjects may be eligible for this study. Participants
      undergo the following procedures:

      Amputees

        -  Questionnaires to assess strength of handedness and footedness and pain perception.

        -  Mirror therapy for phantom limb pain five times a week for 4 weeks in 15-minute
           sessions.

        -  MRI and fMRI scans before starting mirror therapy, after 2 weeks of therapy and after 4
           weeks of therapy. MRI uses a magnetic field and radio waves to image brain tissue. The
           subject lies on a table that can slide in and out of the scanner (a metal cylinder). The
           structural MRI scan lasts about 30 minutes. For fMRI, the subject performs tasks while
           in the scanner in order to show changes in brain activity involved in performing those
           tasks. Subjects are shown pictures of feet and other body parts, are asked to move their
           feet, and receive tactile (touch) stimulation of the foot or other body parts.

      Control Subjects

      One group of control subjects undergoes a single fMRI procedure. A second group of control
      subjects undergoes the same sequence of three fMRIs over the same time period as the amputee
      subjects. None of the control subjects undergo mirror therapy.

      ...
    

Detailed description: 
      Objective: The aim of this study is to investigate phantom limb pain (PLP), cortical
      reorganization and the modulation of PLP by visual input. Mirror therapy (viewing the intact
      limb in a mirror so that it appears to be the missing limb) has been shown to reduce PLP.
      This reduction demonstrates that vision can play a key role in modulating PLP. The study
      proposed here will identify brain regions critical for the success of this therapy using
      functional magnetic resonance imaging (fMRI).

      Study population: Individuals with unilateral amputation of individual limbs and at least
      three episodes of PLP a week. Additionally, we will study amputees without PLP and healthy
      control volunteer subjects with no limb amputations.

      Design: Amputee subjects with PLP will be scanned using fMRI while they undergo mirror
      therapy for PLP. During fMRI scans subjects will see images of hands or feet, move their
      limbs or experience tactile stimulation. Mirror therapy requires four weeks to be effective.
      Amputee subjects will be scanned prior to starting therapy, two weeks after starting mirror
      therapy and again after four weeks of mirror therapy. Mirror therapy sessions will be
      conducted daily and subjects will also complete daily questionnaires (Visual Analogue Scale,
      or VAS, and Short-Form McGill Pain Questionnaire or SF-MPQ) assessing their level of pain and
      number of PLP episodes. Amputees without PLP and one group of healthy control subjects will
      go through the same series of functional imaging scans over the same time period as the
      amputee subjects, allowing us to identify brain changes that may be associated with repeated
      scanning (e.g. due to practice of tasks) rather than resulting from the mirror therapy.
      Another group of control subjects will be scanned once to identify particular brain regions
      that might be involved in the integration of visual, motor and somatosensory information for
      use in the analysis of the amputee subject data.

      Outcome measures: Changes in fMRI activation during the course of mirror therapy will be
      compared with data on the number of episodes of PLP, the average length of episodes, and the
      average intensity of pain assessed using the VAS and SF-MPQ. Analyses will focus on cortical
      regions known to be involved in visual, tactile and motor representations (including primary
      motor cortex, primary and secondary somatosensory cortex and regions of visual cortex
      selectively responsive during the viewing of body parts). Additional brain regions that might
      be involved in integrating visual, motor and somatosensory information will be identified in
      control subjects. Direct comparisons will be made between cortical regions (e.g.
      somatosensory regions) involved in the representation of the amputated limb compared with the
      intact limb and between amputee subject data and control subject data.
    

Time perspective: Prospective
Keywords: Mirror Therapy; Phantom Limb Pain; Amputee; Healthy Volunteer; HV