Cortical reorganization in patients with facial palsy

Ann Neurol. 1997 May;41(5):621-30. doi: 10.1002/ana.410410511.


Possible changes in the organization of the cortex in patients with facial palsy, serving as a model of peripheral motor deefferentation, were investigated by using transcranial magnetic stimulation (TMS) and positron emission tomography (PET). With TMS, the size of the area producing muscle-evoked potentials (MEPs) of the abductor pollicis brevis muscle, the sum of MEP amplitudes within this area, and the volume over the mapping area were compared between both hemispheres in 8 patients. With PET, increases in regional cerebral blood flow, measured with the standard H2(15)O2 bolus injection technique, were compared between 6 patients and 6 healthy volunteers during sequential finger opposition. Patients moved the hand ipsilateral to the facial palsy, the control subjects the right hand. Of 9 patients in total, 5 participated in both experiments. With both methods, an enlargement of the hand field contralateral to the facial palsy was found, extending in a lateral direction, into the site of the presumed face area. The PET data showed that the enlargement of the hand field in the somatosensory cortex (SMC) is part of a widespread cortical reorganization, including the ipsilateral SMC and bilateral secondary motor and sensory areas. We report for the first time, using two different noninvasive methods, that peripheral, mere motor deefferentation is a sufficient stimulus for reorganizational changes in the healthy adult human cortex.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological
  • Adult
  • Aged
  • Brain Mapping
  • Cerebral Cortex / blood supply
  • Cerebral Cortex / diagnostic imaging*
  • Cerebral Cortex / pathology*
  • Cerebrovascular Circulation
  • Evoked Potentials
  • Facial Paralysis / diagnostic imaging*
  • Facial Paralysis / pathology*
  • Facial Paralysis / physiopathology
  • Female
  • Fingers / physiology
  • Functional Laterality
  • Humans
  • Magnetic Resonance Imaging
  • Magnetics
  • Male
  • Middle Aged
  • Movement / physiology
  • Physical Stimulation
  • Somatosensory Cortex / diagnostic imaging
  • Somatosensory Cortex / pathology
  • Tomography, Emission-Computed