Multimodal MRI Study On The Idiopathic Trigeminal Neuralgia

Objective: The present study was to identify the changes of intrinsic brain activity and structural changes in resting-state idiopathic trigeminal neuralgia(ITN)patients by using regional homogeneity(Re Ho),low-frequency fluctuation(ALFF),fractional aptitude of low-frequency fluctuation(f ALFF),voxel-based morphometry(VBM)analysis.Correlations between spontaneous pain intensity and Re Ho,ALFF,f ALFF and VBM were also analyzed.Methods:1.Data acquisition: Functional and structural images were acquired from 23 ITN patients and 23 age,sex-matched healthy volunteers by using resting-state functional magnetic resonance imaging(rs-f MRI).2.To analyze the functional and structural alterations in the brain of ITN patients: the regional homogeneity(Re Ho),low-frequency fluctuation(ALFF)and fraction amplitude of low frequency fluctuation(f ALFF)were compared between two groups to evaluate the differences of functional and structural activity.The discrepancies in volume and density of gray matter between two groups were analyzed and compared applying VBM-DARTEL.Correlation analysis was performed between the corresponding parameters in the regions where notable differences between two groups existed and clinical materials.3.To evaluate the effects of comprehensive treatment on brain function and structure in ITN patients: 9 cases of ITN patients received f MRI scanning again after 6 months comprehensive treatment including medications,physical and neurolytic therapy.The acquired data were used for paired t test to observe the alterations before and after treatment.Resluts:1.As compared with healthy controls,ITN patients showed increased Re Ho values in cerebellum posterior lobe,anterior cingulate cortex,middle temporal gyrus,precuneus,medial frontal gyrus and superior frontal gyrus,decreased Re Ho values were found in the cerebellum and insula.Re Ho values in the cerebellum posterior lobe and middle temporal gyrus were positively correlated with VAS score.Re Ho values in the anterior cingulate cortex,precunneus,medial frontal gyrus,superior frontal gyrus and insula were negatively correlated with VAS score.ITN patients showed increased ALFF values in the brainstem,cerebellum posterior and middle temporal gyrus.Decreased ALFF values were found in the superior frontal gyrus,occipital lobe,caudate,inferior frontal gyrus,posterior cingulate and medial frontal gyrus.ALFF values in the cerebellum posterior lobe,superior frontal gyrus,inferior frontal gyrus and posterior cingulate were positively correlated with VAS score.ALFF values in the occipital lobe,temporal lobe and medial frontal gyrus were negatively correlated with VAS score.ITN patients also showed increased f ALFF values in the left and right side of putamen,occipital lobe and cerebellum.2.In ITN patients,Re Ho,ALFF and f ALFF values in the cerebellum posterior lobe,anterior cingulate cortex,middle temporal gyrus,precuneus,medial frontal gyrus and superior frontal gyrus have undergone varying degrees of change 6 months after comprehensive treatment.Conclusion:1.Functional and anatomical changes are detected in the brain regions related to pain perception and integration in ITN patients,which may play an important role in the pathogenetic and developing process of ITN.2.Comprehension treatment can partly alter the cerebral functional and structural abnormality of ITN patients.Investigation to the level of alteration using MRI may provide reference for evaluation of therapeutic efficiency.