title: Mirror therapy in lower limb amputees--a look beyond primary motor cortex reorganization.
abstract: OBJECTIVE
  Phantom pain in upper limb amputees is associated with the extent of reorganization in the primary sensorimotor cortex. Mirror visual feedback therapy has been shown to improve phantom pain. We investigated the extent of cortical reorganization in lower limb amputees and changes in neural activity induced by mirror therapy.
  
  
  METHODS
  Eight lower limb amputees underwent 12 sessions of MVFT and functional magnetic resonance imaging (fMRI) of the brain before the first and after the last MVFT session. FMRI sessions consisted of two runs in which subjects were instructed to perform repetitive movement of the healthy and phantom ankle.
  
  
  RESULTS
  Before MVFT, the mean phantom pain intensity was 4.6 ± 3.1 on a visual analog scale and decreased to 1.8 ± 1.7 (p = 0.04). We did not observe a consistent pattern of cortical activation in primary sensorimotor areas during phantom limb movements. Following MVFT, increased activity was obtained in the right orbitofrontal cortex during phantom ankle movements. Comparison of cortical activity during movements of the phantom ankle and the intact ankle showed significantly higher activity in the left inferior frontal cortex (pars triangularis).
  
  
  CONCLUSIONS
  These results question the known association between phantom pain and primary sensorimotor reorganization and propose reorganizational changes involving multiple cortical areas in lower limb amputees. Finally, reduction of phantom pain after mirror visual feedback therapy was associated with increased prefrontal cortical activity during phantom ankle movements.
authors.affiliation: Department of Neurology, Medical University of Vienna, Austria. stefan.seidel@meduniwien.ac.at
authors.forename: S
authors.initials: S
authors.lastname: Seidel
authors.forename: G
authors.initials: G
authors.lastname: Kasprian
authors.forename: J
authors.initials: J
authors.lastname: Furtner
authors.forename: V
authors.initials: V
authors.lastname: Schöpf
authors.forename: M
authors.initials: M
authors.lastname: Essmeister
authors.forename: T
authors.initials: T
authors.lastname: Sycha
authors.forename: E
authors.initials: E
authors.lastname: Auff
authors.forename: D
authors.initials: D
authors.lastname: Prayer
mesh_terms: D000328:Adult; D000368:Aged; D000674:Amputees / Q000534:rehabilitation*; D000842:Ankle / Q000294:innervation; D001931:Brain Mapping; D002421:Caudate Nucleus / Q000503:physiopathology; D004292:Dominance, Cerebral / Q000502:physiology; D056228:Feedback, Sensory / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007092:Imagination / Q000502:physiology; D007699:Kinesthesis / Q000502:physiology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D059167:Mirror Neurons / Q000502:physiology*; D009044:Motor Cortex / Q000503:physiopathology*; D009416:Nerve Regeneration / Q000502:physiology*; D009434:Neural Pathways / Q000503:physiopathology; D010147:Pain Measurement; D010591:Phantom Limb / Q000503:physiopathology* / Q000534:rehabilitation*; D026741:Physical Therapy Modalities; D017397:Prefrontal Cortex / Q000503:physiopathology; D016059:Range of Motion, Articular / Q000502:physiology