Comparison of Neuropathic Pain in Neuromyelitis Optica Spectrum Disorder and Multiple Sclerosis
Neuropathic pain is defined by the International Association for the Study of Pain (IASP) as pain that arises as a direct consequence of a lesion or disease affecting the somatosensory system. Such pain is generally resistant to treatment and profoundly affects the quality of life. Neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS) are inflammatory diseases of the CNS, and conditions involving CNS inflammation such as myelitis are associated with neuropathic pain. NMOSD was previously regarded as a variant of MS, but since the identification of pathogenic anti-aquaporin-4 immunoglobulin G (AQP4-IgG), NMOSD has been considered a distinctive disease entity with a pathogenic mechanism that differs from that of MS. Pain was reported to be more common and severe in NMOSD patients than in MS patients. Because of different pathogeneses, the neuropathic pain would be also different between NMOSD and MS groups. However, previous studies have not differentiated neuropathic pain and non-neuropathic pain, and thorough comparative analyses focused on neuropathic pain and its impact on daily life in NMOSD and MS patients have not been conducted. The aim of the current study was therefore to compare the characteristics of neuropathic pain and its impacts on daily life between NMOSD and MS patients.
Short form of the Brief Pain Inventory
The BPI comprises two main components, pain severity and pain-related interference in daily life.14 The severity component is scored from 0 (no pain) to 10 (the severest pain subjects can imagine), and subjects rate the severity of their pain via individual questions for the present, worst, least, and average pain, with the average of these four scores representing their pain severity index score. The pain-related interference score has the following seven domains: general activity, mood, walking ability, capacity for normal work, relationships with other people, sleep, and enjoyment of life. Respondents rate interference in daily life on a scale from 0 (no interference) to 10 (complete interference), and the scores are added to obtain a total pain-related interference score. The current study also investigated whether the patients were currently taking pain medication and the percentage of pain relief they ascribed to that pain medication within 24 hours.
International Journal of Case Reports