Cortical Thickness Alterations in Chronic Pain Disorder: An Exploratory MRI Study

Area of Science:

• Neuroscience
• Radiology
• Psychiatry

Background:

• Chronic pain disorder (CPD) is frequently comorbid with psychiatric conditions like depression and anxiety.
• Brain changes, particularly in limbic circuits, have been associated with CPD.
• Understanding the neurobiological underpinnings of CPD is crucial for effective treatment.

Purpose of the Study:

• To investigate differences in brain cortical thickness (CTh) between patients with CPD and healthy controls.
• To explore the influence of concurrent psychiatric symptoms (depression, anxiety) on CTh in CPD.
• To examine the relationship between CTh and alexithymia in patients with CPD.

Main Methods:

• Utilized high-resolution 3D T1-weighted MRI scans from 23 CPD patients and 23 healthy controls.
• Estimated cortical thickness using Freesurfer software on a 3T scanner.
• Employed ANCOVA, controlling for age, sex, depression, and anxiety scores; corrected for multiple comparisons using FDR (q < .05).

Main Results:

• CPD patients exhibited significantly thinner cortex in the left precentral gyrus, left postcentral gyrus, and left inferior temporal sulcus compared to controls, after accounting for depression.
• A trend towards significance for thinner cortex in CPD was observed in the left precentral gyrus, right middle frontal gyrus, right inferior parietal gyrus, and right anterior temporal pole when accounting for anxiety.
• Cortical thickness in specific regions showed a relationship with alexithymia scores in CPD patients.

Conclusions:

• Brain morphological differences in CPD patients are localized to cortical regions involved in both sensory and affective aspects of pain processing.
• These findings suggest that structural brain changes in CPD extend beyond sensory pathways to include areas related to emotional regulation.
• The study underscores the complex interplay between chronic pain, brain structure, and psychological comorbidities.