Central sensitization across nociceptive, neuropathic, and mixed chronic pain: a multidimensional longitudinal study protocol integrating neurophysiological, cognitive, and psychological measures

Chronic pain represents a major clinical and public health challenge due to its multidimensional nature and frequent resistance to treatment. Beyond the traditional distinction between nociceptive and neuropathic pain, increasing evidence highlights central sensitization as a key transdiagnostic mechanism underlying pain persistence, symptom severity, and reduced treatment response. However, longitudinal studies integrating neurophysiological, cognitive, psychological, and behavioral dimensions across different chronic pain phenotypes remain limited. This study describes a prospective, longitudinal observational protocol aimed at investigating central sensitization in patients with nociceptive, neuropathic, and mixed chronic pain. Participants will be assessed at baseline and at 12-month follow-up using both psychometric and neurophysiological measures, including the Central Sensitization Inventory and laser-evoked potentials, together with standardized evaluations of pain intensity, cognitive functioning, psychological distress, pain self-efficacy, patient engagement, and medication adherence. By combining subjective and objective measures of central sensitization within a multidimensional framework, this study aims to improve the characterization of chronic pain phenotypes and to support a more precise, mechanism-based, and personalized approach to pain management in clinical practiceClinical trial registration: The http://www.ClinicalTrials.gov identifier is NCT07321080.