Frequency of new asymptomatic MRI lesions during attacks and follow-up of patients with NMOSD in a real-world setting

Abstract

Background: We aimed to assess the frequency of new asymptomatic lesions on brain and spinal imaging (magnetic resonance imaging (MRI)) and their association with subsequent relapses in a large cohort of neuromyelitis optica spectrum disorder (NMOSD) patients in Argentina. Methods: We retrospectively reviewed 675 MRI (225 performed during an attack and 450 during the relapse-free period (performed at least 3 months from the last attack)) of NMOSD patients who had at least 2 years of clinical and MRI follow-up since disease onset. Kaplan–Meier (KM) curves were used for depicting time from remission MRI to subsequent relapse. Results: We included 135 NMOSD patients (64.4% were aquaporin-4-immunoglobulin G (AQP4-IgG)-positive). We found that 26 (19.26%) and 66 (48.88%) of patients experienced at least one new asymptomatic MRI lesion during both the relapse-free period and attacks, respectively. The most frequent asymptomatic MRI lesions were optic nerves followed by short-segment myelitis during the relapse-free period and attacks. KM curves did not show differences in the time taken to develop a new relapse. Conclusion: Our findings showed that new asymptomatic lesions are relatively frequent. However, the presence of new asymptomatic MRI lesions during the relapse-free period and at relapses was not associated with a shorter time to developing subsequent relapses.

Asymptomatic spinal lesions in patients with AQP4‐IgG‐positive NMOSD: A real‐world cohort study

“…Another study also showed that the presence of new asymptomatic MRI lesions during the relapse‐free period was not associated with a shorter time to develop subsequent relapses. 10 We speculated that this might be related to treatments and immunosuppressant switches after ASL detection. Furthermore, previous investigations have indicated that a higher frequency of prior relapses is linked to an elevated risk of subsequent relapses.…”

“… 3 In contrast, disability accumulation in NMOSD seems closely linked to attacks, with asymptomatic lesions indicating ongoing disease activity found in only a small fraction of NMOSD patients. 4 , 5 , 6 , 7 , 8 , 9 , 10 These asymptomatic lesions can emerge during attacks or remission, suggesting MRI's heightened sensitivity compared to clinical symptoms. Performing a one‐off MRI scan following an acute episode seems reasonable, allowing a reestablishment of the imaging baseline and enabling comparisons with future relapses.…”