Reduced corticostriatal functional connectivity in temporomandibular disorders

Abstract

Although temporomandibular disorders (TMD) have been associated with abnormal gray matter volumes in cortical areas and in the striatum, the corticostriatal functional connectivity (FC) of patients with TMD has not been studied. Here, we studied 30 patients with TMD and 20 healthy controls that underwent clinical evaluations, including Helkimo indices, pain assessments, and resting-state functional magnetic resonance imaging scans. The FCs of the striatal regions with the other brain areas were examined with a seed-based approach. As seeds, we used the dorsal caudate, ventral caudate/nucleus accumbens, dorsal caudal putamen, and ventral rostral putamen regions. Voxel-wise comparisons with controls revealed that the patients with TMD exhibited reduced FCs in the ventral corticostriatal circuitry, between the ventral striatum and ventral frontal cortices, including the anterior cingulate cortex and anterior insula; in the dorsal corticostriatal circuitry, between the dorsal striatum and the dorsal cortices, including the precentral gyrus and supramarginal gyrus; and also within the striatum. Additionally, we explored correlations between the reduced corticostriatal FCs and clinical measurements. These results directly supported the hypothesis that TMD is associated with reduced FCs in brain corticostriatal networks and that these reduced FCs may underlie the deficits in motor control, pain processing, and cognition in TMD. Our findings may contribute to the understanding of the etiologies and pathologies of TMD.

Neural Pathways of Craniofacial Muscle Pain: Implications for Novel Treatments

“…A recent study indicated a role of striatum. Patients with TMD show decreased corticostriatal functional connectivity, for example, between ventral striatum and ventral frontal cortices (ACC or anterior insula), which might underpin altered motor control, pain processing, and cognition (He et al 2018). A meta-analysis study suggested that these altered brain networks in patients with TMD are largely in common with those in patients with trigeminal neuropathy (e.g., changes in ACC, insular cortex, prefrontal cortex, and basal ganglia) with some distinct components (e.g., involvement of distinct regions of insular cortex and less involvement of thalamocortical connectivity in TMD; Lin 2014).…”

Disrupted Spontaneous Neural Activity and Its Interaction With Pain and Emotion in Temporomandibular Disorders

“…The neurophysiological basis of emotion generation and perception involves a wide range of cortical and subcortical regions (e.g., striatum, hippocampal complex, amygdala, thalamus), which is also known as the fronto-striatal-limbic mood regulation circuit (MRC) ( Anand et al, 2005 ). Neuroimaging studies have found that most brain regions with abnormal neural activity in TMD patients are located in or related to MRC ( Moayedi et al, 2011 , 2012 ; Gerstner et al, 2012 ; Ichesco et al, 2012 ; He et al, 2018 ; Lim et al, 2021 ). However, their relationship with emotional symptoms and the role between pain and emotion remains unclear.…”

Altered Brain Responses to Noxious Dentoalveolar Stimuli in High-Impact Temporomandibular Disorder Pain Patients

“…Neuroimaging studies have further implicated CNS dysregulation in chronic TMD pain, showing that patients exhibit structural [18][19][20][21], functional [22][23][24][25][26][27][28][29], and neurochemical [28,30,31] alterations involving brain regions associated with pain processing [12,32]. Stimulusevoked functional magnetic resonance imaging (sfMRI) is commonly used to investigate CNS mechanisms underlying pain processing in humans [32].…”