Interictal abnormalities of gamma band activity in visual evoked responses in migraine: an indication of thalamocortical dysrhythmia?

Full Abstract

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 hypofunctioning 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.

Author information

Author/s: Coppola, G (G); Ambrosini, A (A); Di Clemente, L (L); Magis, D (D); Fumal, A (A); Gérard, P (P); Pierelli, F (F); Schoenen, J (J);

Affiliation: G.B. Bietti Eye Foundation-IRCCS, Department of Neurophysiology of Vision and Neurophthalmology, Rome, Italy. gianluca.coppola(-atsign-)gmail.com

Journal and publication information

Publication Type: Journal Article; Research Support, Non-U.S. Gov't

Journal: Cephalalgia : an international journal of headache (Cephalalgia), published in England. (Language: eng)

Reference: 2007-Dec; vol 27 (issue 12) : pp 1360-7

Dates: Created 2007/11/23; Completed 2008/01/23; Revised 2008/02/11;

PMID: 17986271, status: MEDLINE (last retrieval date: 2/18/2009, IMS Date: )

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