Brain Resting State-functional Magnetic Resonance Study In Postherpetic Neuralgia

Objective Postherpetic neuralgia is a kind of chronic intractable neuropathic pain.However,the underlying mechanism is still poorly understood.To observe the changes of regional brain activity in resting-state PHN by using fractional amplitude of low frequency fluctuation(fALFF)and regional homogeneity(ReHo)method,and To investigate the correlation between abnormal brain area in fALFF and ReHo and the pain intensity and duration in PHN patients.Methods 15 cases of postherpetic neuralgia patients(PHN group)and 15 health controls(HC group)who were matched in age,gender and education level.The patient group were diagnosed by neurological expert according to the diagnostic criteria of the domestic experts..Using the Holland PHILIPS Achieva 3.0T TX superconducting MRI scanner and 8 channel phase front head circle for regular whole brain scan,three-dimensional brain structure scans and resting-state functional magnetic resonance imaging(RS-fMRI)scan.Pre-processing the RS-fMRI data and analysis data by fALFF,ReHo methods in DPARSF4.3 software.Independent sample T-test between the general data of two groups were performed by SPSS 17.0.Two sample T-test between RS-fMRI(fALFF,ReHo)data of two groups,and correlation analysis between different brain regions in RS-fMRI results of PHN patients with the pain intensity and duration were performed by REST software(age,gender and education level as the convariant).Results1 fALFF analysis:Compared with normal controls,PHN group showed significantly increased fALFF in left anterior lobe of cerebellum/posterior lobe and cerebellar vermis,midbrain,pons,left brainstem,left superior frontal gyrus,left inferior frontal gyrus,left precentral gyrus,left superior temporal gyrus,left middle temporal gyrus,left inferior temporal gyrus,left fusiform gyrus,left supramarginal gyrus,Left inferior parietal lobule,left postcentral gyrus,left paracentral lobule,Left middle occipital gyrus,Left inferior occipital gyrus,left thalamus,left limbic lobe,left insula,left hippocampus,left parahippocampal gyrus,left caudate nucleus,left putamen,left pallidum,left amygdala.Decreased fALFF in Left superior frontal gyrus,right superior frontal gyrus,left middle frontal gyrus,right middle frontal gyrus,left anterior cingulate gyrus,right anterior cingulate gyrus,left rectus gyrus,right rectus gyrus,right precentral gyrus.The fALFF value dfferences of the two groups was showed in the statistical parametric mapping by AlphaSim correction(the threshold was set at p<0.001,cluster size≥54).2 ReHo analysis:Compared with normal controls,PHN group showed significantly increased ReHo in left brainstem,midbrain,left cerebellum,left superior frontal gyrus,left middle frontal gyrus,left precentral gyrus,left supplementary motor area,left paracentral lobule,left superior temporal gyrus,left middle temporal gyrus,left inferior temporal gyrus,left heschl gyrus,left postcentral gyrus,left supramarginal gyrus,left middle occipital gyrus,the left fusiform gyrus,left insula,left cingulate gyrus,left parahippocampal gyrus,left hippocampus,left thalamus,left caudate nucleus,left putamen.Decreased ReHo in left superior frontal gyrus,right superior frontal gyrus,left middle frontal gyrus,right middle frontal gyrus,left anterior cingulate gyrus,right anterior cingulate gyrus,right precentral gyrus.The ReHo value dfferences of the two groups was showed in the statistical parametric mapping by AlphaSim correction(the threshold was set at p<0.001,cluster size≥54).3 No correlations between these abnormal fALFF,ReHo and pain intensity in the PHN group.4 No correlations between these abnormal fALFF,ReHo and duration in the PHN group.Conclusion PHN patients with multiple fALFF,ReHo abnormal changes in the brain area,suggesting that the corresponding brain area of neuronal activity intensity,homogeneity has changed,indicating that PHN can lead to abnormal brain function in the corresponding area,and PHN patients with local brain activity abnormalities Not limited to the pain matrix,in addition to the area associated with pain perception,but also related to cognitive,exercise,emotional activity area,further indicating that PHN patients with brain function changes in plasticity.Combined use of RS-fMRI two methods(fALFF,ReHo)can effectively evaluate the resting state of brain function changes,more conducive to explore the PHN neurological damage,for a better understanding of PHN central mechanism to provide Some reference information.