Differences in Pain, Pain-Related Physical and Emotional Functioning and MS-Related Impairment By the Number of Pain Locations in MS

Background: Between 13 to 80% of patients with Multiple Sclerosis (MS) experience pain that is commonly associated with functional difficulties, emotional distress, and decreased quality of life. MS-related pain is associated with multiple body parts such as back pain, spasticity in the extremities, and facial/head pain associated with optic neuritis and trigeminal neuralgia. 

Objectives: This study examined differences in the experience of pain and its impacts by number of pain sites among persons with MS. It was hypothesized that persons with evidence of widespread pain would report greater pain and pain- and MS-related interference for physical and emotional functioning.   

Methods: Data were collected as part of a randomized clinical trial of cognitive-behavioral therapy for MS-related pain. Twenty-five participants completed the baseline evaluation, including self-reports of severity and location, pain-related physical functioning (West Haven-Yale Multidimensional Pain Inventory), and emotional functioning (Profile of Mood States and Beck Depression Inventory-Second Edition), and measures of MS-related functional status (MS Functional Composite). Participants were categorized into one of two groups by the number of pain locations, which was determined by quartiles. A p value of 0.1 was chosen due to the low sample size.

Results: Participants with five or more pain locations endorsed greater fatigue (p = 0.039) and depressive symptomatology (p = 0.055). They were also engaged in more activities away from home (p = 0.027) than participants with four or less pain locations. There were no significant differences between the two groups in terms of their pain severity (p = 0.626), numbers of years of pain (p = 0.944), disease duration (p = 0.408), age (p = 0.501), or performance on the MS Functional Composite (p = 0.626).

Conclusions: While the sample size was low, our findings suggest that persons with MS who had pain in more locations experience greater fatigue and depression even though they did not report greater pain severity or duration. Their engagement in more outside activities than participants with fewer pain locations suggests that while having pain in more locations may affect energy and mood symptoms, it may not necessarily interfere in their ability to engage in instrumental activities. Future research should more closely examine the relationship between pain and emotional functioning, and the hypothesis that negative mood may mediate the spread of pain to other body sites among persons with MS.