Functional connectivity of amygdala in refractory epilepsy:a resting-state functional study of magnetic resonance imaging

Abstract

To explore the functions of amygdala functional connectivity in the pathogenesis of refractory epilepsy with resting-state functional magnetic resonance imaging (RS-fMRI). A total of 19 patients with refractory epilepsy were recruited from August 2013 to June 2014. And 19 healthy persons were selected as the controls.No obvious epileptogenic lesions of intracranial structures were found on multi-modal neuroimaging.Ictal and interictal epileptic activities on long-term video electroencephalogram (EEG) showed spine spread spike and wave in bilateral cerebral hemispheres. All fMRI data were preprocessed after RS-fMRI scanning. Then left and right amygdalas were selected as regions of interest (ROIs) for calculating the linear correlation between amygdala and whole brain. As relative to the control group, the changes of brain areas in functional connectivity were examined for the intractable epilepsy group. Compared with the controls, left amygdala in refractory epilepsy group showed increased functional connectivity with bilateral fusiform gyrus, bilateral calcarine gyrus and right lingual, on the contrary decreased functional connectivity with bilateral cuneus, bilateral precuneus, bilateral caudatas and left thalamus.However, right amygdala demonstrated increased functional connectivity with bilateral calcarine gyrus and bilateral linguals, but decreased functional connectivity with bilateral caudatas and left putamen (P < 0.05). Altered functional connectivity of amygdala reflects its dysfunction in refractory epilepsy patients. It suggested that amygdala is an important component of "epileptic network" participating in the occurrence and development of refractory epilepsy.