Altered intrinsic functional connectivity of the salience network in childhood absence epilepsy

Abstract

Intrinsic connectivity analysis provides an original way for evaluating functional impairments in epilepsy. Disturbances in the salience network (SN) have been positing an important interplay in disorders of consciousness and attention. This study aims to assess the intrinsic connectivity of the SN in childhood absence epilepsy (CAE). Resting state fMRI was performed in 21 patients with CAE and 21 healthy controls. The SN was extracted using group independent component analysis with dual-regression. Intrinsic functional integration was evaluated through voxelwise comparisons between patients and controls. Patients showed a decreased functional integration of the SN in the right anterior insula, anterior temporoparietal junction, and bilateral dorsolateral frontal cortex and increased connectivity in the anterior and middle cingulate gyrus and caudate nuclei. A leftward lateralization was observed in the anterior insula and anterior temporoparietal junction in CAE. Moreover, the lateralized index in the anterior insula was significantly correlated with the duration of epilepsy. These results support the disturbance of intrinsic activity in the SN which may be linked to the interruption of salient information processing and associated with the attentional dysfunction in CAE. Our findings demonstrate the potential value of intrinsic activity in the SN for the investigation of attention process and may help to better understand the association between intrinsic activity in the SN and consciousness.

Keywords: Absence seizures; Epilepsy; Functional MRI; Independent component analysis; Intrinsic connectivity network; Salience network.