Neural Sensitisation and Neuropsychological Alterations in Painful Chronic Pancreatitis

Chronic pancreatitis (CP) is a progressive inflammatory disorder affecting 50-100 per 100,000 adults globally, with 50-80% of patients experiencing debilitating abdominal pain. Despite advances in understanding pancreatic pathology, pain management remains inadequate, leading to high rates of opioid dependence (40%) and reduced quality of life. Traditional models attribute CP pain to peripheral mechanisms (e.g., ductal hypertension, inflammation), yet many patients report persistent pain even after surgical or endoscopic interventions. This paradox highlights the critical role for central mechanisms, including central sensitization.

Central sensitization refers to increased responsiveness of nociceptive neurons in the central nervous system (CNS) to normal or subthreshold afferent input. In CP, prolonged peripheral inflammation may induce long-lasting changes in the brain's pain processing pathways. Emerging literature in other chronic pain conditions (e.g., fibromyalgia, irritable bowel syndrome) supports the notion that central sensitization is associated with altered brain connectivity and neurochemical imbalances. However, few studies have explored this in CP, and none have integrated central sensitization with neuropsychological dysfunction, which frequently co-occurs in chronic pain states.

Understanding these CNS mechanisms is essential for redefining pain management in CP. By combining clinical phenotyping, advanced neuroimaging (resting-state fMRI and MR spectroscopy), our study aims to offer a comprehensive picture of how altered brain function contributes to the pain experience. Identifying neurobiological markers of pain will also support the development of mechanism-based therapies and allow better stratification of patients who may benefit from central neuromodulatory interventions.

This prospective observational study will enroll 200 participants (120 with painful CP, 30 with painless CP, and 50 healthy controls) over one year. Participants will undergo clinical assessments, pain detection questionnaires (Izbicki, painDetect), and evaluations for quality of life (EORTC QLQ-C30 + PAN28), mental state (HADS), and sleep quality (PSQI). The primary assessments include Pancreatic Quantitative Sensory Testing (P-QST) to evaluate sensitization, resting-state fMRI to assess brain connectivity, and MR Spectroscopy to evaluate brain metabolites. Blood samples will be collected from all participants to quantify blood-based metabolites for exploratory biomarker analysis to identify potential correlates with pain phenotypes in chronic pancreatitis.

Inclusion criteria

• Diagnosed with CP confirmed by CECT, MRCP, or EUS based on Cambridge or Rosemont criteria.
• Age 18-60 years.
• Both genders

Exclusion criteria

• Recent episode of acute pancreatitis or ongoing pain (VAS >5).
• Pancreatic cancer and other significant comorbidities.
• Recent use of antidepressants, anxiolytics, high-potency opioids, or neuromodulators.
• Pregnancy and lactation.
• Inability to give informed consent.