Neuromyelitis Optica Spectrum Disorders - Retrospective Analysis of Clinical and Paraclinical Findings

Aim: The aim of this study was to describe the clinical picture of patients with NMO spectrum disorders (NMO SD) in the Czech Republic, including comparison of patients with disease onset before and after 50 years of age in the context of longitudinally extensive transverse myelitis (LETM) and optic nerve involvement. Another objective was to evaluate cerebrospinal fluid samples and aquaporin-4 antibody (AQP4-IgG) seropositivity. Methods: A systematic retrospective analysis of clinical and paraclinical findings in 32 patients with NMO SD was performed. The retinal nerve fiber layer (RNFL) thickness in each eye was measured with optical coherence tomography. Severity of neurological deficit was expressed by the EDSS score. Results: NMO SD are more frequent in women (8: 1). Median age of disease onset was 36 years. Median disease duration was 10.5 years. Median EDSS score was 4.5 (range 1.0-8.5) and median disease duration 10.5 years (range 0.5-24). AQP4-IgG were found in the serum of 31 out of the 32 patients and their titer positively correlated with the EDSS score. The RNFL thickness of the right eye (median 63 pm) and the left eye (median 58 pm) was below the lower limit of normal (97 pm) in 57% and 64% of patients, respectively. The RNFL thickness correlated with the disease duration. Myelitis as the first manifestation of the disease was more frequent in patients older than 50 years (p < 0.05). Compared to remission, patients with a relapse had increased protein levels and element count in the cerebrospinal fluid (p < 0.001 for both parameters). Conclusion: LETM is typically the first clinical manifestation of NMO patients older than 50 years and is associated with severe neurological deficit at the early stages of the disease.