Factors correlated with neuropathic pain in patients with neuromyelitis optica spectrum disorder

Background: Neuropathic pain in neuromyelitis optica spectrum disorder (NMOSD) is common but has always been overlooked. This study was conducted to explore factors correlated with neuropathic pain in NMOSD and to evaluate associations between pain and quality of life.

Methods: In this cross-sectional study, NMOSD patients were interviewed face-to-face. The Brief Pain Inventory, Douleur Neuropathique 4, and Neuropathic Pain Symptom Inventory scales were used to evaluate pain. Patients completed the Beck Depression Inventory-II and Social Functioning-36 tests to evaluate depression and quality of life.

Results: A total of 122 NMOSD patients were enrolled. Eighty-one (66.4%; 95% CI, 39.9% to 92.9%) had current pain, of which 35 (28.7%; 95% CI, 20.7% to 36.7%) had neuropathic pain. Forty-nine (40.2%; 95% CI, 31.5% to 48.9%) patients experienced depression, which was moderate to severe in 22 patients. Multinomial logistic regression showed that significantly more patients with neuropathic pain had depression than those with other pain (OR, 4.15; 95% CI, 1.40 to 12.35; P=0.010) or no pain (OR, 5.65; 95% CI, 1.74 to 18.18; P=0.004). Significantly more patients with neuropathic pain had initial spinal cord involvement than those in the no-pain group (OR, 15.78; 95% CI, 1.37 to 182.15; P=0.027). Quality of life was severely affected in NMOSD patients with neuropathic pain. Only 29.6% were treated with analgesics, and none were prescribed antidepressants.

Conclusion: Depression was correlated with neuropathic pain and was often overlooked. Initial spinal cord involvement might indicate a higher risk for neuropathic pain. Neuropathic pain in NMOSD patients requires scrutiny.