Brain Responses in CFS and TMD to Autonomic Challenges: An Exploratory fMRI Study.

Area of Science:

• Neuroscience
• Autonomic Nervous System Research
• Medical Imaging

Background:

• Chronic fatigue syndrome (CFS) and temporomandibular disorders (TMDs) share poorly understood pathophysiology and involve autonomic nervous system (ANS) dysfunction.
• Brain regions crucial for pain, fatigue, and autonomic function, such as the insular cortex and basal ganglia, are implicated in both CFS and TMD.

Purpose of the Study:

• To investigate potential common neurophysiologic mechanisms underlying CFS and TMD by examining brain responses to autonomic challenges.
• To determine if patients with CFS exhibit different brain responses to ANS activation depending on the presence or absence of TMD.

Main Methods:

• An exploratory functional imaging study utilizing 3-T magnetic resonance imaging (MRI).
• Participants included patients with CFS who screened positive for TMD (n=26), patients with CFS who screened negative for TMD (n=16), and age-matched controls (n=10).
• The Valsalva maneuver was employed to activate the ANS during MRI scanning.

Main Results:

• All groups showed increased brain activation in regions including the frontal gyri, putamen, thalamus, and insular cortex during the Valsalva maneuver.
• Patients with CFS and TMD exhibited greater left insular cortex activity compared to CFS patients without TMD.
• CFS patients with TMD also showed increased left caudate nucleus activity compared to controls.

Conclusions:

• Heightened brain activity in cortical and subcortical regions during autonomic challenges may be influenced by fatigue and pain.
• ANS dysfunction is suggested as a potential contributing factor to the symptoms and comorbidity of CFS and TMD.
• Further research is needed to elucidate the complex interplay between CFS, TMD, and autonomic functions for potential therapeutic targets.