An fMRI study on the specific modulation of brain responses to transient pain by anxiety in college students / 中华行为医学与脑科学杂志

ABSTRACT

Objective:To investigate whether anxiety state and anxiety trait modulate specifically pain-induced brain responses by comparing the brain activations induced by painful stimulation and those by tactile stimulation in college students with different levels of anxiety state or anxiety trait.Methods:From April 2017 to September 2017, sixty-two college students were tested in Tianjin Medical University General Hospital.Each subject’s anxiety trait and anxiety state were assessed by the state-trait anxiety inventory (STAI) prior to the fMRI experiment.During the fMRI experiment, each subject received painful and tactile stimuli.Their brain responses to each stimulus were collected by the MRI scanner, and the perceived intensity rating of each stimulus was collected using the visual analogue scale (VAS). The pain and tactile brain activation values of subjects with different state anxiety levels and different trait anxiety levels were compared.The fMRI brain activation was detected using general linear model.For each type of anxiety (state or trait), two-way ANOVA was performed to detect the interaction between anxiety level and stimulus modality on brain responses and two-sample t-tests were performed to analyze the specific form of interaction in each brain region. Results:There were interactions between state anxiety and stimulation modality on the activation intensity of bilateral posterior parietal lobe, dorsolateral prefrontal lobe and other brain regions( P<0.05, cluster-level FWE corrected) .The brain responses to tactile stimuli (5.66±0.65) in these areas were significantly stronger than those to painful stimuli (1.24±0.55) in the group of middle-level anxiety state ( P<0.001), but no significant difference was found in the other two groups (both P>0.05). For anxiety trait, a few brain areas in bilateral occipital cortex showed significant interactions between anxiety level and stimulus modality.The brain responses to tactile stimuli (8.38±1.00) in these areas were significantly stronger than those to painful stimuli (3.19±1.12) in the group of high-level anxiety trait ( P=0.001), but no significant difference was found in the other two groups (both P>0.05). Conclusion:The modulatory effects of anxiety (both state and trait) on brain responses are different between painful and tactile conditions.It provides important evidence for unveiling the brain mechanisms of the specific modulation of anxiety on pain, and suggests that patients' anxiety trait and anxiety state should be considered during clinical treatment of pain.