Identifying neuropathic pain in patients with multiple sclerosis: a cross-sectional multicenter study using highly specific criteria

BACKGROUND: Pain is a common and heterogeneous complication of multiple sclerosis (MS). In this multicenter, cross sectional study, we aimed at investigating the prevalence of pain in MS using highly specific criteria for distinguishing the different types of pain. MATERIALS AND METHODS: After a structured interview, in patients with pain, clinical examination and DN4 questionnaire were used for distinguishing neuropathic and nociceptive pain. In subjects with neuropathic pain, the Neuropathic Pain Symptom Inventory was used for differentiating neuropathic pain symptoms. RESULTS: We enrolled 1249 participants (832 F, 417 M, mean age 33.9 years, mean disease duration 8 years, mean EDSS 3.2); based on clinical evaluation and DN4 score 429 patients (34.34%) were classified with pain (470 pain syndromes): 286 nociceptive pain syndromes and 184 neuropathic pain syndromes. Multivariate analysis showed that pain was associated with age, gender and disease severity and that neuropathic pain was distinctly associated with EDSS. CONCLUSIONS: Our study, providing definite information on the prevalence, characteristics and variables associated with neuropathic pain due to MS, shows that a more severe disease course is associated with a higher risk of neuropathic pain. Our findings might, therefore, provide a basis for improving the clinical management of this common MS complication.