Alteration of parahippocampal gyrus functional connectivity in the role of memory disorder after concussion: a fMRI study

Abstract

Objective To investigate the alteration of functional connectivity and its significance in post-concussion syndrome (PCS) patients with memory disorders using resting-state functional magnetic resonance imaging (rs-fMRI). Methods From September 2014 to April 2015, 28 PCS patients with memory disorders admitted to the Department of Neurosurgery, Anhui Provincial Hospital, Anhui Medical University and 28 health controls (HC) recruited in the same period were studied. The RS-fMRI data were collected and processed. The left and right parahippocampal gyri were used as the regions of interest (ROI) to make functional connectivity with the whole brain and were analyzed in order to obtain the altered brain areas of hippocampal gyrus and whole brain functional connectivity in patients with PCS. Results The functional connectivity of the left parahippocampal gyrus and bilateral prefrontal lobe, bilateral temporal lobe, right precuneus, and right precentral gyrus reduced (all P<0.05), and the functional connectivity with the bilateral occipital lobe, bilateral lingual lobe, and left superior parietal lobule enhanced (all P<0.05). The functional connectivity of the right parahippocampal gyrus, right inferior frontal gyrus, bilateral temporal lobe, and bilateral occipital lobe reduced (all P<0.05), and the functional connectivity with the bilateral middle frontal gyrus, left inferior frontal gyrus, right orbital frontal gyrus, left inferior temporal gyrus, left middle occipital lobe, bilateral angular gyrus, right lingual lobe, and left parietal lobule enhanced (all P<0.05). Conclusion In resting state, the abnormality of function connectivity of the parahippocampal gyrus in patients with PCS may be one of the reasons for resulting in memory impairment in patients with PCS. Key words: Post-concussion syndrome; Parahippocampal gyrus; Functional connectivity; Functional magnetic resonance imaging