Altered inhibitory modulation of somatosensory cortices in paroxysmal kinesigenic dyskinesia

Mov Disord. 2013 Oct;28(12):1728-31. doi: 10.1002/mds.25656. Epub 2013 Sep 20.

Abstract

Background: The objective of this study was to clarify the excitability profiles of the somatosensory cortices in patients with paroxysmal kinesigenic dyskinesia.

Methods: Whole-head magnetoencephalography was used to record the somatosensory evoked fields elicited by paired-pulse electric stimulation of the median nerve in 15 patients with paroxysmal kinesigenic dyskinesia and in a control group of 18 age-matched, healthy volunteers. Twelve of the patients were studied in both the drug-off and drug-on state.

Results: The paired-pulse inhibition ratios of the primary somatosensory cortical P35m responses and the secondary somatosensory cortical responses were significantly greater in drug-off patients with paroxysmal kinesigenic dyskinesia compared with either the drug-on patients or the control group. No significant difference in paired-pulse inhibition ratio was observed between the drug-on patients with paroxysmal kinesigenic dyskinesia and the control group.

Conclusions: In patients with paroxysmal kinesigenic dyskinesia, intracortical inhibition of the primary and secondary somatosensory cortical areas is impaired, and the associated hyperexcitable phenomenon is modulatable by antiepileptic drugs.

Keywords: magnetoencephalography; paired-pulse inhibition; paroxysmal kinesigenic dyskinesia; somatosensory cortical inhibition; somatosensory evoked fields.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Chorea / physiopathology*
  • Dystonia
  • Electric Stimulation
  • Evoked Potentials, Somatosensory / physiology
  • Female
  • Humans
  • Magnetoencephalography
  • Male
  • Median Nerve / physiopathology
  • Neural Inhibition / physiology*
  • Somatosensory Cortex / physiopathology*

Supplementary concepts

  • Familial paroxysmal dystonia