Do Patients with Neuromyelitis Optica Spectrum Disorder Experience Prodromal Neurologic Symptoms Preceding Their First Attack?

Researchers found that approximately 1 in 7 patients with aquaporin-4 antibody positive (AQP4-IgG+) neuromyelitis optica spectrum disorder (NMOSD) experienced neurologic symptoms before their first attack.

While a few cases report the presence of AQP4 antibodies up to 16 years before a first NMOSD attack, it is unclear whether patients commonly experience a prodrome. Understanding a potential neurologic prodrome could improve early diagnosis and management of NMOSD.

In this study, the researchers reviewed medical records of participants from four demyelinating disease centers as part of the Canadian NMOSD cohort study, CANOPTICS. Patients included in the study met the 2015 diagnostic criteria for AQP4-IgG+ NMOSD. Neurologic symptoms occurring at least 30 days prior to the first attack were identified and recorded.

Of the 116 participants, 17 (14.7%) experienced prodromal neurologic symptoms. These included numbness or tingling (n = 9), neuropathic pain (n = 5), visual disturbance (n = 4), tonic spasms (n = 2), Lhermitte sign (n = 2), severe headache (n = 2), incoordination (n = 2), weakness (n = 1), psychosis (n = 1), and seizure (n = 1). In total, eight participants underwent brain, orbit, or spinal cord MRIs, with five showing T2 lesions. The time between the onset of prodromal symptoms and the first NMOSD attack ranged from 1.5 to 245 months, with a median duration of 14 months.

The limitations of this study include its small sample size and its retrospective design, which led to variability in clinical documentation and neuroimaging. Prodromal symptoms may have been underreported since participants were not always asked about prior neurologic issues. Selection bias may have occurred, as only individuals enrolled in CANOPTICS were included. Limited neuroimaging and ophthalmologic data also restricted the findings. The exclusion of symptoms occurring within 30 days of the first attack may have underestimated the prevalence of prodromal symptoms, and some early symptoms may represent missed or early stages of an attack.

The authors concluded, "1 in 7 people with NMOSD experienced neurologic symptoms before their first attack. Further investigation of a possible NMOSD prodrome is warranted.”
 

Reference

Lee S, Marrie RA, Fadda G, et al. Is there a prodrome to NMOSD? An investigation of neurologic symptoms preceding the first NMOSD attack. Mult Scler. Published online Sep 11, 2024. doi:10.1177/13524585241275491