Multimodal MRI Study On The Herpes Zoster Pain And Postherpetic Neuralgia

Objective: To detect a)the functional and structural abnormalities of brains between herpes zoster(HZ),postherpetic neuralgia(PHN)patients and healthy controls;b)the differences between HZ patients and PHN patients transitioned from HZ with self-control method by employing the brain multimodal MRI technologies.Methods: 1.Images collection: 32 HZ patients,18 PHN patients and 20 healthy controls were enrolled in the first study.The other study enrolled 12 PHN patients that transited from HZ.The resting-state magnetic imaging resonance(rsf MRI)methods and voxel based morphometry(VBM)technology were used to calculate the functional and structural bain parameters.2.Regional homogeneity(ReHo)and fractional amplitude of low frequency fluctuation(fALFF)values were calculated to estimate the brain activity differences between HZ,PHN and control group.VBM method was used to calculate the grey matter volume(GMV).Correlations between the brain parameters(i.e.,ReHo,fALFF,VBM)and pain intensity or pain duration were analysed.3.ReHo,fALFF and VBM were jointly used to assess the influence of HZ and PHN on brain activity and brain GMV.The correlations between changes in the brain(i.e.,brain activity and GMV)and pain intensity or pain duration were analysed too.Results: 1.HZ brain showed intenser ReHo and fALFF values in bilateral thalamus,pariental lobe and cingulated gyrus relative to that of healthy controls,while the temporal lobe,the cerebellum and the occipital lobe etc.showed weaker ReHo and fALFF intensities.The ReHo and fALFF values in the cerebellum posterial lobe etc.were positively correlated with pain intensity while the right cingulated gyrus showed negative correlation.2.PHN brain showed intenser ReHo and fALFF values in bilateral cerebellum,the thalamus and the right cingulate gyrus relative to that of healthy control,while the temporal lobe,the parietal lobe and the occipital lobe etc.showed weaker ReHo and fALFF intensities.The ReHo and fALFF values of the cerebellum posterial lobe,the thalamus,the parietal lobe etc.showed positive correlation with pain intensity and pain duration while the temporal lobe etc.showed negative correlation.3.PHN brain showed greater ReHo and fALFF values in bilateral cerebellum etc.,while the temporal lobe,the parietal lobe,the occipital lobe and cingulated gyrus etc.showed weaker ReHo and fALFF intensities relative to HZ brain.In addition,PHN brain showed smaller GMV at the occipital lobe,and occipital lobe and greater GMV in cerebellum and pons etc.as evidenced by the VBM results.4.When the 12 HZ patients developed to PHN,the PHN brain exhibited: a)greater ReHo and fALFF values in bilateral cerebellum and frontal lobe etc.,while the occipital lobe and the limbic lobe etc.showed weaker ReHo and fALFF intensities relative to HZ group.The ?ReHo and ?fALFF values(PHN-HZ)in the cerebellum posterial lobe and the left cuneus showed positive correlation with pain duration(the time gap between two MRI scans)while the left middle cingulated gyrus showed negative correlation with pain duration.b)PHN brain showed smaller GMV at the thalamus,the frontal lobe and the parietal lobe,and greater GMV in the cerebellum posterial lobe and the parietal lobe.In addition,the GMV reduction(HZ-PHN)of thalamus was positively correlated with pain duration,while the GMV increase in the middle temporal gyrus was positively correlated with pain duration.Conclusions: 1.HZ and PHN induced brain activity changes in several pain related brain areas although they influenced different brain regions.2.Several areas showed brain activity and GMV changes when HZ patients developed to PHN.3.The cerebellum and the occipital lobe etc.may play crucial roles in the transiton from HZ to PHN and they could be potential targets to prenvent and cure the chronic pain of PHN.