Poster No:
2517
Submission Type:
Abstract Submission
Authors:
Patcharaporn Srisaikaew1, Timur Latypov2, Alborz Noorani2, Mojgan Hodaie2,1
Institutions:
1University Health Network, Toronto, Canada, 2University of Toronto, Toronto, Canada
First Author:
Co-Author(s):
Mojgan Hodaie, Prof.
University of Toronto|University Health Network
Toronto, Canada|Toronto, Canada
Introduction:
Trigeminal neuralgia (TN) is a severe chronic neuropathic pain disorder characterized by intense shock-like pain in distributions of the trigeminal nerve branches. A distinctive feature of TN is the fear of recurring attacks, and the thought of recurrence of pain uniformly results in pain-related anxiety and stress. Previous structural brain imaging studies provide evidence of the association between chronic pain, pain-related stress and emotion, and the loss of gray matter (GM) volume. The prefrontal, anterior cingulate, and insular cortices are well-documented brain regions involved in pain mechanisms and are affected by stress and negative affect, and could be associated with the development of emotion disorders after experienced chronic pain (Obermann et al., 2013; Fritz et al., 2016; Hayes et al., 2017; Yuan et al., 2017). However, whether these altered cortical regions alter following surgical intervention for pain remain unclear. In this study, we aim to investigate the alterations of cortical thickness involved in pain mechanism and associated emotion-affective circuit in chronic pain patients. We used TN as a model to study pain and its potential resolution after surgery.
Methods:
3T anatomical T1-weighted images from 119 TN patients including pre-surgery (pre-sx) and 6 months after Gamma Knife radiosurgery (GKRS; post-sx) timepoints, and age-/sex-matched healthy controls (HC) were collected and analyzed. Freesurfer was used to perform the volumetric segmentation (cortical thickness, mm3) of the ventromedial prefrontal cortex (vmPFC), dorsolateral prefrontal cortex (dlPFC), anterior cingulate cortex (ACC), and insula cortex in both hemispheres. The estimated total intracranial volume in each hemisphere of each participant was calculated to account for the head size difference within the study cohorts. The significant statistical level was set at p<.05. All reported p-values were corrected for the multiple comparisons with the false discovery rate procedure (q<.05).
Results:
The results showed the thickness (volume) of vmPFC, dlPFC, ACC, and insula cortices were significantly reduced in TN with persistent pain symptoms when compared to the controls (q<0.01). Comparing between pre- and post-surgical timepoints, these brain regions were significantly normalized (increased in volume) in TN only after successful pain relief (q<0.001). However, this effect was found only in patients who reported at least 75% pain relief after successful GKRS (q<0.01).
Conclusions:
Our findings indicate the brain morphological changes observed in patients with TN are affected by chronic pain and may be linked to negative affect following pain experienced. Of importance, pain relief by surgical intervention normalizes these cortical alterations in the chronic pain cohort. The observed normalization pattern suggests dynamic cortical thickness alterations in chronic pain regarding neuronal plasticity. This also suggested that the investigation of the related mechanism (e.g., processing emotion and behaviour regulation) whereby these dynamic alterations take place should be considered in future studies. Recovery of pain-associated symptoms including negative affect is an important component in the management of chronic pain patients.
Modeling and Analysis Methods:
Image Registration and Computational Anatomy
Segmentation and Parcellation
Neuroanatomy, Physiology, Metabolism and Neurotransmission:
Cortical Anatomy and Brain Mapping 2
Novel Imaging Acquisition Methods:
Anatomical MRI
Perception, Attention and Motor Behavior:
Perception: Pain and Visceral 1
Keywords:
Affective Disorders
Computational Neuroscience
Emotions
Pain
STRUCTURAL MRI
Sub-Cortical
1|2Indicates the priority used for review
Provide references using author date format
Fritz, H.C. et al. (2016) “Chronic Back Pain Is Associated With Decreased Prefrontal and Anterior Insular Gray Matter: Results From a Population-Based Cohort Study,” The journal of pain: official journal of the American Pain Society, 17(1), pp. 111–118.
Hayes, D. J. et al. (2017) “Affective Circuitry Alterations in Patients with Trigeminal Neuralgia,” Frontiers in neuroanatomy, 11, p. 73.
Obermann, M. et al. (2013) “Gray matter volume reduction reflects chronic pain in trigeminal neuralgia,” NeuroImage, 74, pp. 352–358.
Yuan, C. et al. (2017) “Gray Matter Abnormalities Associated With Chronic Back Pain: A Meta-Analysis of Voxel-based Morphometric Studies,” The Clinical journal of pain, 33(11), pp. 983–990.