The Clinical Journal of Pain Summary
Highlight from The Clinical Journal of Pain (Volume 34, Issue 7, July 2018)
Altered Spontaneous Brain Activity in Patients With Idiopathic Trigeminal Neuralgia: A Resting-State Functional MRI Study
Jie Yuan, Song Cao, Yue Huang, Yi Zhang, Peng Xie, Yu Zhang, Bao Fu, Tijiang Zhang, Ganjun Song, Tian Yu, and Mazhong Zhang
- Department of Anesthesiology, Shanghai Children's Medical Center, Shanghai Jiaotong University School of Medicine, Shanghai.
- Departments of Anesthesiology.
- Guizhou Key Laboratory of Anesthesia and Organ Protection, Zunyi Medical College, Zunyi, Guizhou, China.
- Radiology, Affiliated Hospital of Zunyi Medical College.
Idiopathic trigeminal neuralgia (ITN), the most prevalent disease resulting in facial pain, is characterized by paroxysmal, electric, lancinating pain sensations and a variety of sensory experiences. It usually is evoked by innocuous sensory stimuli but often occurs spontaneously. According to current opinion, ITN may be caused by an ectatic blood vessel (either an artery or vein) affecting the trigeminal nerve at the root entry zone of the brain stem and secondary demyelination, likely mediated by microvascular ischemic damages.
This study was designed to detect alterations in intrinsic brain activity in people with ITN and to use these data to identify specific brain areas that may be associated with the development and persistence of this debilitating facial pain. Regional homogeneity (ReHo) and low-frequency fluctuation (fALFF) were analyzed in 23 patients with ITN and 23 age- and sex-matched pain-free controls to detect functional abnormality in the brains of patients with ITNs. Correlations between ReHo and fALFF were analyzed. ITN pain intensity also was assessed in the ITN group.
Compared with pain-free controls, patients with ITN demonstrated abnormal local coherence (ReHo) and intrinsic brain activity (fALFF) in many brain regions. The patterns of ReHo and fALFF alterations in patients with ITN were comparable with patterns previously described in other chronic pain conditions and seem to reflect the cortical adaptation to long-term, highly frequent pain perceptions. Abnormal local coherence and spontaneous brain activity occurred in regions of the brain that are associated with pain perception and modulation. Compared with pain-free controls, patients with ITN had widely distributed ReHo alterations such as decreased ReHo in the right cerebellum and left insula and increased ReHo in the posterior lobe of the right cerebellum and the right anterior cingulate cortex, left middle temporal gyrus, right precuneus, left medial frontal gyrus, and left superior frontal gyrus. The abnormal ReHo values of several regions were associated with self-reported pain intensity. Compared with pain-free controls, patients with ITN had fALFF increases in the left and right putamen.
Results showed that patients with ITN had substantial abnormalities of brain activity in the cerebellum, cingulate cortex, temporal lobe, putamen, occipital lobe, limbic lobe, precuneus, medial and superior frontal gyrus, and insula compared with healthy controls. These brain regions mainly are involved in pain modulation and perception. Investigators also documented that self-reported pain intensity was associated with alternative ReHo in the cerebellum, cingulate cortex, precuneus, insula, and medial and superior frontal gyrus. These results add important information to the limited studies on brain functional alterations in patients with ITN.