Interictal Abnormalities of Gamma Band Activity in Visual Evoked Responses in Migraine: An Indication of Thalamocortical Dysrhythmia?

Cephalalgia ◽  
2007 ◽  
Vol 27 (12) ◽  
pp. 1360-1367 ◽  
Author(s):  
G Coppola ◽  
A Ambrosini ◽  
L Di Clemente ◽  
D Magis ◽  
A Fumal ◽  
...  
Keyword(s):  
High Frequency ◽  
Gamma Band ◽  
Pattern Reversal ◽  
Evoked Responses ◽  
Visual Evoked Responses ◽  
High Frequency Oscillations ◽  
Thalamocortical Dysrhythmia ◽  
Gamma Band Activity ◽  
Band Activity ◽  
Visual Evoked

Between attacks, migraineurs lack habituation in standard visual evoked potentials (VEPs). Visual stimuli also evoke high-frequency oscillations in the gamma band range (GBOs, 20–35 Hz) assumed to be generated both at subcortical (early GBOs) and cortical levels (late GBOs). The consecutive peaks of GBOs were analysed regarding amplitude and habituation in six successive blocks of 100 averaged pattern reversal (PR)-VEPs in healthy volunteers and interictally in migraine with (MA) or without aura patients. Amplitude of the two early GBO components in the first PR-VEP block was significantly increased in MA patients. There was a significant habituation deficit of the late GBO peaks in migraineurs. The increased amplitude of early GBOs could be related to the increased interictal visual discomfort reported by patients. We hypothesize that the hypo-functioning serotonergic pathways may cause, in line with the thalamocortical dysrhythmia theory, a functional disconnection of the thalamus leading to decreased intracortical lateral inhibition, which can induce dishabituation.

scholarly journals Stimulus-induced Gamma Power Predicts the Amplitude of the Subsequent Visual Evoked Response

2018 ◽  
Author(s):  
Mats W.J. van Es ◽  
Jan-Mathijs Schoffelen
Keyword(s):  
Gamma Band ◽  
Evoked Response ◽  
Pattern Reversal ◽  
Visual Evoked Response ◽  
Cortical Areas ◽  
Gamma Power ◽  
Visual Cortical ◽  
Gamma Band Activity ◽  
Band Activity ◽  
Visual Evoked

AbstractThe efficiency of neuronal information transfer in activated brain networks may affect behavioral performance. Gamma-band synchronization has been proposed to be a mechanism that facilitates neuronal processing of behaviorally relevant stimuli. In line with this, it has been shown that strong gamma-band activity in visual cortical areas leads to faster responses to a visual go cue. We investigated whether there are directly observable consequences of trial-by-trial fluctuations in non-invasively observed gamma-band activity on the neuronal response. Specifically, we hypothesizedthat the amplitude of the visual evoked response to a go cue can be predicted by gamma power in the visual system, in the window preceding the evoked response. Thirty-three human subjects (22 female) performed a visual speeded response task while their magnetoencephalogram (MEG) was recorded. The participants had to respond to a pattern reversal of a concentric moving grating. We estimated single trial stimulus-induced visual cortical gamma power, and correlated this with the estimated single trial amplitude of the most prominent event-related field (ERF) peak within the first 100 ms after the pattern reversal. In parieto-occipital cortical areas, the amplitude of the ERF correlated positively with gamma power, and correlated negatively with reaction times. No effects were observed for the alpha and beta frequency bands, despite clear stimulus onset induced modulation at those frequencies. These results support a mechanistic model, in which gamma-band synchronization enhances the neuronal gain to relevant visual input, thus leading to more efficient downstream processing and to faster responses.Significance statementGamma-band activity has been associated with many cognitive functions and improved behavioral performance. For example, high amplitude gamma-band activity in visual cortical areas before a go cue leads to faster reaction times. However, it remains unclear through which neural mechanism(s) gamma-band activity eventually affects behavior. We tested whether the strength of induced gamma-band activity affects evoked activity elicited by a subsequent visual stimulus. We found enhanced amplitudes of early visual evoked activity, and faster responses with higher gamma power. This suggests that gamma-band activity affects the neuronal gain to new sensory input, and thus these results bridge the gap between gamma power and behavior, and support the putative role of gamma-band activity in the efficiency of cortical processing.

scholarly journals Flash and Pattern Reversal Visual Evoked Responses in Normal and Demented Elderly

Cortex ◽  
1992 ◽  
Vol 28 (2) ◽  
pp. 289-293 ◽  
Author(s):  
Eric E. Brodie ◽  
Donald Allan ◽  
David N. Brooks ◽  
James McCulloch ◽  
Wallace S. Foulds
Keyword(s):  
Pattern Reversal ◽  
Evoked Responses ◽  
Visual Evoked Responses ◽  
Visual Evoked

>Checkerboard Visual Evoked Response in Evaluation and Management of Pituitary Tumors

Neurosurgery ◽  
1979 ◽  
Vol 5 (5) ◽  
pp. 553-558 ◽  
Author(s):  
Peggy S. Gott ◽  
Martin H. Weiss ◽  
Michael Apuzzo ◽  
Joseph P. Van Der Meulen
Keyword(s):  
Visual System ◽  
Pituitary Tumor ◽  
Visual Fields ◽  
Pattern Reversal ◽  
Checkerboard Pattern ◽  
Evoked Responses ◽  
Visual Evoked Response ◽  
Visual Evoked Responses ◽  
Suprasellar Extension ◽  
Visual Evoked

Abstract As a routine part of the evaluation of patients with pituitary tumor, visual evoked responses (VERs) to checkerboard pattern reversal were recorded from 83 patients with tomographically documented pituitary tumor. VER tests were correlated with examinations of visual acuity, color perception, and visual fields and with computerized tomographic scan evidence of suprasellar extension of the tumor. The purpose of the VER recording was to determine the presence of visual system compression by the tumor and thus contribute to the decision of whether surgery was necessary. Each of the patients who had suprasellar extension of the tumor sufficient to produce a visual field abnormality also had an abnormal VER. In addition, some patients with suprasellar extension had normal visual fields but abnormal visual evoked responses. Thus, the VER provided earlier evidence of suprasellar extension causing visual system compromise than did conventional visual tests.

Sign in / Sign up

Export Citation Format

Share Document