The Application Of The Resting-state FMRI Technology In Post-concussion Symptoms

Objective To provide theoretical basis for the pathophysiological mechanism research of patients with Post-concussion symptoms (PCS) by using noninvasive testing technology in vivo brain function:(1) To explore the alteration of Regional homogeneity (ReHo) in PCS patients by resting-state functional magnetic resonance imaging (rs-fMRI); (2) To explore whether or not the small world property of brain functional network changes in patients with brain concussion syndrome by the method of resting state functional magnetic resonance imaging technology and graph theory.Methods (1) From August 2013 to May 2015,20 patients with PCS and 20 healthy controls with the age-,sex- and education level matched were recruited in Affiliated Anhui Provincial Hospital, Anhui Medical University. The resting state functional MRI data of PCS group and healthy controls group were acquired; the preprocessing was performed by the SPM8 software package. The ReHo data analyze were performed by rest software package and then carry on the smoothing processing. As relative to healthy controls, the alteration of brain regions in ReHo were found for PCS patients. (2) After the fMRI data was obtained from 24 patients at 3 months after concussion with PCS and 21 age-, gender- and education-matched healthy controls. Applying the SPM8 software package for data preprocessing and then build the functional brain network by the graph theory method. Finally, the property of small world networks (when γ>1,λ≈1, and σ=γ/λ>1, the network has the property of small world) and its parameters--the changes and significance of the clustering coefficient (Cp) and the average shortest path length (Lp) of 2 groups were analyzed through the two-sample t-test.Results (1) Compared with healthy controls, the PCS group showed significantly decreased ReHo in bilateral thalamus, bilateral insula, bilateral lingual and increased ReHo in bilateral posterior cingulate cortex (PCC), bilateral praecuneus, right supramarginal (P<0.05). (2) Compared with the healthy controls based on the graph theory analysis, in the range of sparsity 0.05 to 0.4, both of PCS group and healthy met the property of small world (y value,1.871±0.253 vs 2.178±0.178; λvalue,1.105±0.050 vs 1.08310.015; o value,1.65410.249 vs 1.94210.155), but the property of small world changed in PCS patients compared with the healthy controls, and there were significant difference in y value between the 2 groups (t=3.350, P=0.030). Both the Cp value and Lp value of the PCS group were more than those of the healthy control group (Cp, 0.310±0.022 vs 0.290±0.026; Lp,4.720±3.489 vs 3.7431±1.617), however, there was only significant difference in Cp value (P<0.05).Conclusion (1) we found the ReHo abnormal by the resting state fMRI technology and the ReHo analysis is helpful to explore the mechanism of nerve dysfunction in PCS patients. (2) Based on the resting state fMRI and graph theoretical analysis, our studies found that the PCS patients still met the small world property. Compared with the healthy controls, PCS group showed local brain area dysfunction. These dysfunction brain areas may be form the neural basis of the persistent symptoms. Therefore, rs-fMRI techniques as a non-invasive living brain function detection technology provides a new angle for brain function and the changes of relevant brain regions in PCS patients, which makes it possible to further study the pathophysiological mechanisms of PCS patients.