Systematic assessment and characterization of chronic pain in multiple sclerosis patients

Pain is one of the most disabling clinical symptoms in patients with multiple sclerosis (MS). Several studies have already assessed the prevalence of pain in MS patients, reporting variable results, probably due to methodological differences. The aim of this single-centre cross-sectional study was to define the prevalence and characteristics of chronic pain in a population of MS patients using validated tools, and to analyse these data in relation to demographic and clinical features, including disease duration and disability (EDSS and its single functional system scores). Of 397 enrolled patients, 23 were excluded due to a Beck's Depression Inventory Score > 19. In the remaining 374 patients, the overall prevalence of chronic pain was 52.1%, most frequently affecting the lower limbs (36.9%). Neuropathic pain was the most frequent type of chronic pain (89 patients, overall prevalence of 23.7%) and was associated with a sensory functional system involvement. Pain intensity was significantly higher in patients with neuropathic pain as opposed to patients with non-neuropathic pain. Patients with chronic pain and, in particular, patients with neuropathic pain had significantly higher EDSS scores than those without pain. Only 24% of patients with chronic pain and 33% of patients with neuropathic pain were on a specific long-lasting treatment for pain. The present study supports the routine assessment of neuropathic pain in MS patients, especially in those with a sensory functional system involvement, in order to avoid underdiagnosing and undertreating a potentially disabling condition.