Long-standing gadolinium enhancement in a patient with aquaporin-4-positive myelitis.

We report the case of a very long-standing spinal cord gadolinium enhancement in a patient with AQP4-positive myelitis, presenting with two clinical relapses while on rituximab. Additional tests conducted to investigate potential differential diagnoses returned negative and the therapy was switched to satralizumab. Follow-up revealed a resolution of symptoms and lesion enhancement. The total duration of lesion enhancement was 14 months. Recognizing the possibility of long-lasting enhancement in AQP4-positive myelitis is crucial for diagnostic accuracy. Moreover, it may indicate subclinical disease activity, and might suggest the need for close magnetic resonance imaging (MRI) monitoring and an adjustment in therapeutic strategy.