Emotional burden among MS patients: associations between specific chronic pain diagnoses and psychological features

Central neuropathic pain (CNP) and musculoskeletal pain (MSP) are often comorbid with multiple sclerosis (MS), yet data on the emotional burden entailed by this comorbidity are very limited. We studied whether MS patients with CNP exhibited greater emotional burden and pain severity than those with MSP and whether this emotional burden was attributed to the MS, the chronic pain, or both. Participants were 125 MS patients (55 with CNP; 30 with MSP; 40 MS pain-free) and 30 healthy controls (HCs). Participants completed questionnaires assessing pain interference, pain catastrophizing, depression, anxiety, stress, hypervigilance, and chronic pain. Group comparisons and a two-step cluster analysis were performed, and the association between cluster membership and clinical group membership was evaluated. Chronic pain was stronger and more widespread in the CNP group than in the MSP group. Both pain groups had higher pain interference, pain catastrophizing, and stress compared to MS pain-free and HC groups. All MS groups had greater depression levels compared to HCs, and the CNP group had the highest anxiety level. The "high psychological distress" cluster comprised mainly participants with CNP (57%), and the "minimal psychological distress" cluster comprised mainly the MS pain-free and HC groups. In conclusion, CNP seems to induce greater emotional burden and pain severity than does MSP. Whereas depression may be attributed to MS, and anxiety to CNP, enhanced pain interference, catastrophizing, and stress may be attributed to the comorbidity of MS and chronic pain. Identifying these traits among MS patients and targeting them in management programs may contribute to more effective, individually based care.