Altered Brainstem Pain Modulating Circuitry Functional Connectivity in Chronic Painful Temporomandibular Disorder.

Area of Science:

• Neuroscience
• Pain Research
• Medical Imaging

Background:

• Altered brainstem pain-modulation circuit function is implicated in chronic pain.
• Preclinical models show changes in these circuits, but human data is limited.
• Painful temporomandibular disorders (TMD) are a form of chronic non-neuropathic pain.

Purpose of the Study:

• To investigate alterations in brainstem pain-modulating circuits in individuals with painful TMD.
• To compare static and dynamic functional connectivity (FC) in TMD patients versus controls.

Main Methods:

• Resting-state functional magnetic resonance imaging (fMRI) was used.
• Static FC (whole scan correlation) and dynamic FC (short window correlation) were analyzed.
• 16 TMD subjects and 45 control subjects participated.

Main Results:

• TMD subjects exhibited greater static FC between the rostral ventromedial medulla and the subnucleus reticularis dorsalis and spinal trigeminal nucleus compared to controls.
• Increased variability in dynamic FC was observed between the rostral ventromedial medulla and these same brainstem regions in TMD subjects.
• No significant differences were found in the midbrain periaqueductal gray matter or locus coeruleus.

Conclusions:

• Individuals with painful TMD display altered static and dynamic functional connectivity within the brainstem pain-modulation network.
• These alterations may facilitate descending pain signals, contributing to chronic pain perception.
• Targeting these brainstem circuits could offer a therapeutic approach for chronic pain management.