Patients with neuromyelitis optica spectrum disorder (NMOSD) can experience repeated relapses and increased neurologic disability, such as pain. However, little is known about the impact of relapses on pain and subsequent pain medication use in patients with NMOSD.
A retrospective, observational, cohort analysis was conducted to examine pain medication use in patients with NMOSD.
Patients with anti-aquaporin-4 immunoglobulin G-positive (AQP4+) NMOSD in the University of Utah Health Care System were identified. Electronic data, including patient-level treatments/therapies, medications, health status, and physician notes, were extracted from the Enterprise Data Warehouse and confirmed via chart review by Neurology and Pharmacotherapy faculty members.
Forty-seven patients with AQP4+ NMOSD were included in the analysis. The average age at diagnosis was 46 years; 75% were female, and 70% were white. At the initial presentation of disease, 25 (53%) patients had optic neuritis, 15 (32%) had transverse myelitis, and 7 (15%) had a mixed or unknown presentation. The mean follow-up time was 4 years (standard deviation 3.64 years). During the follow-up period, 14 of 47 patients experienced 26 provider-documented relapses.
Overall, pain medication was used by 45 (95.7%) of 47 patients with AQP4+ NMOSD. A higher proportion of relapsing patients used pain medication than nonrelapsing patients: opioid analgesics (79% vs 58%), non-narcotic analgesics (93% vs 43%), anticonvulsants (86% vs 46%), and musculoskeletal therapy agents (71% vs 46%). Furthermore, among the relapsing patients with AQP4+ NMOSD, pain medication use increased within 90 days of the relapse when compared with the prerelapse use of pain medications: opioids analgesics (27% vs 12%), non-narcotic analgesics (39% vs 12%), anticonvulsants (35% vs 27%), and musculoskeletal therapy agents (39% vs 23%).
In this study, more patients with AQP4+ NMOSD who experienced relapses used pain medication than nonrelapsing patients. In addition, the increase in pain medication use within 90 days following a relapse suggests that pain is associated with relapse activity in patients with NMOSD. Treatment strategies that reduce relapses should be considered for all patients with NMOSD, not only to reduce traditional measures of neurological disability, but also to reduce the burden of pain and accompanying use of relapse-related pain medication.