Wan-Yu Hsu1, Shang-Yeong Kwan, Kwong-Kum Liao, Rou-Shayn Chen, Yung-Yang Lin. 1. Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan; Laboratory of Neurophysiology, Taipei Veterans General Hospital, Taipei, Taiwan; Integrated Brain Research Laboratory, Taipei Veterans General Hospital, Taipei, Taiwan.
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.
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.