Resting State Functional Magnetic Resonance Imaging For Lumbar Disc Herniation

Objective: To investigate alteration in cerebral functional areas and default mode network, the correlation between the intensity of spontaneous neural activity and pain intensity or disease duration in lumbar disc herniation(LDH) patient at rest in order to provide further insight about brain mechanisms during pain.Methods: 13 cases of generalized lumbar disc herniation patients and 13 healthy controls(HC) were recruited for this study. A 3.0T scanner was used to generate images of brain which were dealed with SPM8 statistical package based on MATLAB 2010.(1)Amplitude of low frequency fluctuations( ALFF) were obtained to compare the difference in brain regions between the LDH and HC group.(2) Region of interest(ROI) based on Posterior cingulate cortex(PCC) were drawn to calculate the time domain correlation of ROI with whole brain voxels, construct the Default mode network(DMN) of LDH, and analyze the difference of DMN between LDH patients and HC.(3) In LDH group, the correlation between the average value of ALFF in ROIs and visual analog scale(VAS) of pain or disease duration was analyzed.Results:(1)Compared to in HC group, Higher ALFF value in LDH goup was noted in areas of Primary sensory/motor cortex(S1/M1), inferior frontal, superior temporal and inferior temporal/fusiform gyri of the right side, and superior temporal/fusiform and parahippocampal gyri of the left side whereas lower ALFF value in LDH goup was noted in PCC, left insula and bilateral basal ganglia, bilateral medial prefrontal cortex, right supramarginal/middle temporal gyri and left cerebellar lobe, P<0.05,K>40.(2) Positive correlation between DMN and PCC were noted at anterior cingulate cortex, PCC, precuneus, bilateral angular gyrus,inferior temporal gyri, bilateral medial prefrontal cortex, superior frontal gyrus, brain stem and cerebellum; whereas negative correlalation were mainly located in middle cingulate gyrus, bilateral dorsolateral prefrontal cortex, supplementary motor area, bilateral middle frontal, temporal and occipital lobes. In the LDH group, the reduced functional connectivity between brain regions and PCC are bilateral m PFC, PCC, right superior/inferior temporal gyrus; Increased functional connectivity brain region is present at the left inferior parietal lobule.(3) Positive correlation between the average ALFF and VAS were noted at right frontal gyri, PCC, left insula, bilateral basal ganglia, right inferior temporal/fusiform gyri, the correlation coefficients R are 0.612、0.621、0.662、0.468、0.677、0.580, P<0.05.(4) Negative correlation between the average ALFF and disease duration were noted at right inferior temporal / fusiform gyri, The correlation coefficient R is-0.569, P<0.05.Conclusions:(1) ALFF abnormalities caused by pain in LDH involve in a wide range of brain functional areas of pain perception, movement, emotion and memory, cognitive.(2) The rested state DMN of LDH patients is disturbed, which indicate that LDH patients exist cognitive and behavioral disorders.(3) Positive correlation between the average ALFF at right S1/M1, PCC, left insula, bilateral basal ganglia, right inferior temporal/fusiform gyri and VAS in LDH, suggest that ALFF perhaps can be used as a parameter of pain intensity, objectively.(4) Although Negative correlation between the intensity of spontaneous neural activity at right inferior temporal/fusiform gyri, the right inferior temporal gyrus and disease duration of LDH were noted, whether ALFF in these area can be use a parameter to assess the change of disease duration in LDH still needs further study.