Swayamprabha Nair1, Richard P Morse1, Stephen H Mott2, Scott A Burroughs1, Gregory L Holmes3. 1. Department of Neurology, Geisel School of Medicine at Dartmouth, Dartmouth-Hitchcock Medical Center, Hanover, NH, United States. 2. Department of Neurological Sciences, University of Vermont College of Medicine, Burlington, VT, United States. 3. Department of Neurology, Geisel School of Medicine at Dartmouth, Dartmouth-Hitchcock Medical Center, Hanover, NH, United States; Department of Neurological Sciences, University of Vermont College of Medicine, Burlington, VT, United States. Electronic address: Gregory.Holmes@uvm.edu.
Abstract
BACKGROUND: Spikes and spike-and-wave discharges on the EEG of children are a strong biomarker of epilepsy. There is increasing evidence that these EEG abnormalities also impair brain function and result in transitory cognitive impairment. Studies in animal models have shown that EEG spikes alters single cell firing and that such impairment in firing may extend beyond the duration of the spike-and-wave discharge. Whether interictal epileptiform discharges have lasting effects on EEG activity in humans is not known. METHODS AND RESULTS: The EEGs of 60 consecutive children with focal or interictal spike-and-wave discharges were evaluated using power spectral analysis to determine if there were any changes in power spectra from before to after the interictal abnormalities. Neither focal spike-and-wave nor generalized spike-and-wave discharges had any effect on the EEG frequency or spectral power following the discharge. CONCLUSION: While interictal EEG discharges temporarily alter neural activity during the duration of the spike-and-wave discharge, there is no evidence that alterations of spectral power continue beyond the duration of the interictal discharge. The effects of interictal activity on EEG rhythms therefore appear to be quite transient and confined to the duration of the interictal discharge.
BACKGROUND: Spikes and spike-and-wave discharges on the EEG of children are a strong biomarker of epilepsy. There is increasing evidence that these EEG abnormalities also impair brain function and result in transitory cognitive impairment. Studies in animal models have shown that EEG spikes alters single cell firing and that such impairment in firing may extend beyond the duration of the spike-and-wave discharge. Whether interictal epileptiform discharges have lasting effects on EEG activity in humans is not known. METHODS AND RESULTS: The EEGs of 60 consecutive children with focal or interictal spike-and-wave discharges were evaluated using power spectral analysis to determine if there were any changes in power spectra from before to after the interictal abnormalities. Neither focal spike-and-wave nor generalized spike-and-wave discharges had any effect on the EEG frequency or spectral power following the discharge. CONCLUSION: While interictal EEG discharges temporarily alter neural activity during the duration of the spike-and-wave discharge, there is no evidence that alterations of spectral power continue beyond the duration of the interictal discharge. The effects of interictal activity on EEG rhythms therefore appear to be quite transient and confined to the duration of the interictal discharge.
Authors: Jonathan K Kleen; Rod C Scott; Gregory L Holmes; David W Roberts; Melissa M Rundle; Markus Testorf; Pierre-Pascal Lenck-Santini; Barbara C Jobst Journal: Neurology Date: 2013-05-17 Impact factor: 9.910