Pain Mapping and Neuropathic Features of Common Shoulder Pathologies

Abstract

Introduction: Pain maps can help quantify the distribution of pain but are not commonly used in shoulder pathology. This prospective study aims to quantify severity, type and distribution of pain associated with common shoulder pathologies using patient derived pain maps. Material and Methods: 219 patients with 5 common shoulder pathologies were prospectively recruited with diagnosis confirmed definitively at time of procedure. Patients completed maps for nociceptive pain and abnormal sensation. Visual Analogue Score and a validated neuropathic pain questionnaire (painDetect) were completed. Maps were generated with images stacked and overlaid using an FFT based image algorithm to generate pathology specific heat maps. Results: Neuropathic pain was likely in 20% of all patients based on painDetectscores. Abnormal sensation was present overall in 49.3%. 16.1% experienced symptoms below the elbow and 11.6% in the hand. Frozen shoulder appears to have the highest frequency of distal limb symptoms. Conclusion: This study provides a clear guide to the distribution and nature of pain arising from procedure confirmed common shoulder conditions. We have demonstrated that neuropathic pain is prevalent in common shoulder pathologies and may spread as far as the hand. Therefore, pain in this distribution should not be dismissed as cervical as this will lead to a delay in the treatment of the shoulder pathology.