Clinical characteristics and evolution of dural enhancement in NMOSD: A retrospective case series

This study aimed to investigate the clinical and neuroimaging characteristics in patients with AQP4-IgG-positive neuromyelitis optica spectrum disorder (AQP4-NMOSD) accompanied by dural enhancement.

A retrospective analysis was conducted on ten AQP4-NMOSD patients with dural enhancement from two medical centers. All patients underwent serial contrast-enhanced MRI during follow-up. Longitudinal clinical and radiological data were collected to evaluate relapse patterns and temporal changes in dural enhancement.

The cohort had a median onset age of 31 years (IQR 24-45) with a male-to-female ratio of 3:7. At enrollment, the median disease duration was 6.2 months (IQR 1.5-35.9), the median attack number was 2 (IQR 1-3), and the median EDSS score was 6.5 (IQR 2.0-8.0). Nine patients were in the acute phase, and one patient was in the remission phase. After enrollment, nine patients received immunosuppressive therapy to prevent relapse, while one patient received prednisone alone. Over a median follow-up period of 39.6 months (IQR 28.2-45.7), five patients treated with biologics remained relapse-free. However, relapses occurred in three patients receiving conventional immunosuppressants, one patient on prednisone, and one patient treated with biologics. At enrollment, except for dural enhancement, nine patients presented with contrast-enhancing lesions in the optic nerve or brain/spinal cord parenchyma, while one patient showed no such lesions. Concurrent leptomeningeal enhancement was observed in seven patients. Dural enhancement persisted or progressed in relapsing patients but reduced in non-relapsing cases during follow-up.

In AQP4-NMOSD, neuroimaging may reveal dural enhancement associated with disease activity.