Fractional amplitude of low‐frequency fluctuation changes of specific cerebral regions in patients with toothache: A functional magnetic resonance imaging study

BACKGROUND: Previous studies have indicated that pain‐related diseases can result in significant functional alterations in the brain. However, differences in spontaneous brain activity in toothache (TA) patients remain unclear. OBJECTIVE: To investigate altered spontaneous brain activity in patients with TA and its underlying mechanisms using the resting‐state functional magnetic resonance imaging–fractional amplitude of low‐frequency fluctuation (rsfMRI–fALFF) technique. METHODS: Twelve patients with TA and 12 non‐toothache controls (NTCs) (matched for sex, age, and level of education) were enrolled. Spontaneous cerebral activity variations were investigated using the rsfMRI–fALFF technique in all individuals. The mean fALFF values of the TA patients and NTCs were classified using receiver operating characteristic (ROC) curves. The correlations between fALFF signals of distinct brain regions and clinical manifestations of TA patients were evaluated using Pearson's correlation analysis. RESULTS: TA patients showed lower fALFF values in the left superior frontal gyrus, medial; right superior frontal gyrus, dorsolateral; and left median cingulate and paracingulate gyri (LDCG) than the NTCs. Moreover, ROC curve analysis indicated that the area under the curve of each cerebral region studied had high accuracy. Besides, in the TA group, the visual analog scale score was negatively correlated with fALFF signal values of the LDCG (r = .962, p < .001). CONCLUSION: Abnormal spontaneous activity was detected in numerous brain regions in patients with TA, which may be valuable for understanding the brain processing mechanism underlying TA. These regional changes in brain activity may serve as effective clinical indicators of TA.