Differences in Rolandic phase-locking between ictal and interictal epochs (i.e. ictal phase synchronization) between children with normal and abnormal motor function across defined frequency bands.

<p>Children with motor deficits had ictal desychronization (relative to interictal period), most significantly in the gamma3 (81–150 Hz) band.</p

Intraoperative photograph showing placement of grid over right hemisphere.

<p>(A) Asterisk indicates motor hand area as determined by cortical stimulation. (B) Three-dimensional reconstruction showing grid (light pink dots), MRI lesion (dark pink area), magnetoencephalographic (MEG) cluster (green dots). Square shows 3×3 montage used for PLV analysis.</p

Linear regression of (A) motor tasks and (B) non-motor tasks with differences in clustering between ictal and interictal epochs.

<p>Extent of Rolandic ictal declustering (relative to interictal epochs) significantly correlated with the degree of motor impairment based on the Finger tap test in the contralateral, but not ipilateral hand and did not show significant correlation with non-motor deficits.</p

Graph theoretical analysis-based topographic mapping of grid showed significant local declustering in the Rolandic cortex during the ictal period relative to interictal epoch (ictal minus interictal) at 80 Hz in children with abnormal motor function.

<p>There was no significant difference between the two groups of children interictally and there was a trend towards more declustering in the ictal period (p = 0.06). There was a significant difference between the extent of ictal declustering (relative to interictal epochs) in children with normal and abnormal motor function.</p

Linear regression of (A) motor tasks and (B) non-motor tasks with differences in phase-locking between ictal and interictal epochs.

<p>Extent of ictal desynchronization (relative to interictal epochs) was significantly correlated with degree of neuropsychological impairment for the grooved pegboard task in the hand contralateral to recording, but not the ipsilateral hand or non-motor tasks.</p