Reduced cortical thickness of brain areas involved in pain processing in patients with chronic pancreatitis

Abstract

Background & aims: Patients with painful chronic pancreatitis (CP) might have abnormal brain function. We assessed cortical thickness in brain areas involved in visceral pain processing.

Methods: We analyzed brain morphologies of 19 patients with painful CP and compared them with 15 healthy individuals (controls) by using a 3T magnetic resonance scanner. By using an automated method with surface-based cortical segmentation, we assessed cortical thickness of the primary (SI) and secondary (SII) somatosensory cortex; prefrontal cortex (PFC); frontal cortex (FC); anterior (ACC), mid (MCC), and posterior (PCC) cingulate cortex; and insula. The occipital middle sulcus was used as a control area. The pain score was determined on the basis of the average daily amount of pain during 1 week.

Results: Compared with controls, patients with CP had reduced overall cortical thickness (P = .0012), without effects of modification for diabetes, alcoholic etiologies, or opioid treatment (all P values >.05). In patients with CP, the cortical thickness was decreased in SII (P = .002, compared with controls), PFC (P = .046), FC (P = .0003), MCC (P = .001), and insula (P = .002). There were no differences in cortical thickness between CP patients and controls in the control area (P = .20), SI (P = .06), ACC (P = .95), or PCC (P = .42). Cortical thickness in the affected areas correlated with pain score (r = 0.47, P = .003).

Conclusions: In patients with CP, brain areas involved in pain processing have reduced cortical thickness. As a result of long-term, ongoing pain input to the neuromatrix, cortical thickness might serve as a measure for overall pain system dysfunction, as observed in other diseases characterized by chronic pain.