Visual cortex excitability and plasticity associated with remission from chronic to episodic migraine

Cephalalgia, 04/27/2012

The pattern of P100m responses to consecutive stimulation changes with the transition from chronic migraine (CM) to episodic migraine (EM). Visual cortex plasticity might be a potential biomarker reflecting clinical remission of CM.

Methods

  • At baseline, 25 patients with CM were studied interictally.
  • For each patient, 30 sequential blocks of 50 P100m responses were obtained by MEG.
  • Sub–averaged amplitudes at blocks 2, 9, 16, 23 and 30 were further compared with that at block 1 to assess response habituation or potentiation (i.e. significant decrease or increase at either block vs block 1).
  • The same study was repeated in those patients who remitted from CM to EM after topiramate treatment.

Results

  • In total, 10 CM patients remitted to EM after treatment.
  • In the follow–up study of these patients during the interictal stage, the P100m at block 1 decreased in amplitude from 53.6±6.6nAm before remission to 43.0±5.1nAm (p=0.028), and the responses at subsequent blocks switched from habituation (amplitude block 30block 1, p=0.028).

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