Altered Functional Connectivity Between the Insula and the Cingulate Cortex in Patients With Temporomandibular Disorder: A Pilot Study

• Published in: Headache Vol. 52; no. 3; pp. 441 - 454
• Main Authors: Ichesco, Eric, Quintero, Andres, Clauw, Daniel J., Peltier, Scott, Sundgren, Pia M., Gerstner, Geoffrey E., Schmidt-Wilcke, Tobias
• Format: Journal Article
• Language: English
• Published: Malden, USA Blackwell Publishing Inc 01.03.2012; Wiley-Blackwell; Wiley Subscription Services, Inc
• Subjects: Adaptations; Adult; Biological and medical sciences; Brain; Brain mapping; Case-Control Studies; Central nervous system; Cerebral Cortex - blood supply; Cerebral Cortex - pathology; chronic pain; cingulate cortex; Clinical Medicine; Cortex (cingulate); Cortex (insular); Cortex (visual); Data processing; Disorders of higher nervous function. Focal brain diseases. Central vestibular syndrome and deafness. Brain stem syndromes; Female; functional connectivity; Functional Laterality; Functional magnetic resonance imaging; Gyrus Cinguli - blood supply; Gyrus Cinguli - pathology; Headache; Humans; Image Processing, Computer-Assisted; insular cortex; Klinisk medicin; Magnetic Resonance Imaging; Male; Medical and Health Sciences; Medical sciences; Medicin och hälsovetenskap; Nervous system (semeiology, syndromes); Neural networks; Neural Pathways - blood supply; Neural Pathways - physiology; Neurology; Oxygen - blood; Pain; Pain Measurement; Pain perception; Physical Stimulation - adverse effects; Pilot Projects; Pressure; Pressure - adverse effects; Radiologi och bildbehandling; Radiology, Nuclear Medicine and Medical Imaging; Rest - physiology; Seeds; Statistics, Nonparametric; Studies; temporomandibular disorder; Temporomandibular Joint Disorders - pathology; Vascular diseases and vascular malformations of the nervous system; Young Adult; Human; Headache; Nervous system diseases; chronic pain; Stomatology; Diseases of the osteoarticular system; Temporomandibular joint dysfunction; Cerebral disorder; Chronic; Pain; functional connectivity; Cingulate cortex; Central nervous system disease; temporomandibular disorder; Arthropathy; Neurological disorder; Insular cortex; Cerebrovascular disease; Maxillary disease
• ISSN: 0017-8748; 1526-4610; 1526-4610
• DOI: 10.1111/j.1526-4610.2011.01998.x

Background.— Among the most common chronic pain conditions, yet poorly understood, are temporomandibular disorders (TMDs), with a prevalence estimate of 3‐15% for Western populations. Although it is increasingly acknowledged that central nervous system mechanisms contribute to pain amplification and chronicity in TMDs, further research is needed to unravel neural correlates that might abet the development of chronic pain. Objective.— The insular cortex (IC) and cingulate cortex (CC) are both critically involved in the experience of pain. The current study sought specifically to investigate IC–CC functional connectivity in TMD patients and healthy controls (HCs), both during resting state and during the application of a painful stimulus. Methods.— Eight patients with TMD, and 8 age‐ and sex‐matched HCs were enrolled in the present study. Functional magnetic resonance imaging data during resting state and during the performance of a pressure pain stimulus to the temple were acquired. Predefined seed regions were placed in the IC (anterior and posterior insular cortices) and the extracted signal was correlated with brain activity throughout the whole brain. Specifically, we were interested whether TMD patients and HCs would show differences in IC–CC connectivity, both during resting state and during the application of a painful stimulus to the face. Results.— As a main finding, functional connectivity analyses revealed an increased functional connectivity between the left anterior IC and pregenual anterior cingulate cortex (ACC) in TMD patients, during both resting state and applied pressure pain. Within the patient group, there was a negative correlation between the anterior IC–ACC connectivity and clinical pain intensity as measured by a visual analog scale. Conclusions.— Since the pregenual region of the ACC is critically involved in antinociception, we hypothesize that an increase in anterior IC–ACC connectivity is indicative of an adaptation of the pain modulatory system early in the chronification process. (Headache 2012;52:441‐454)