Plasma exchange in severe spinal attacks associated with neuromyelitis optica spectrum disorder

Abstract

Background Plasma exchange (PE) is increasingly undertaken in diseases involving humoral factors and is proven to be beneficial in acute demyelinating diseases. Spinal attacks in relapsing neuromyelitis optica (NMO) and in extensive transverse myelitis (ETM) – a truncated form of NMO with spinal involvement – are usually devastating. Objective We retrospectively studied the outcome of PE-treated versus steroid-only treated spinal attacks in relapsing NMO and ETM. Methods We included 96 severe spinal attacks in 43 Afro-Caribbean patients. PE was given as an add-on therapy in 29 attacks. Expanded disability status score (EDSS) was obtained before attack, during the acute and residual stage. We defined the ΔEDSS as the rise from basal to residual EDSS. Results The ΔEDSS was found to be lower in the PE-treated group (1.2 ± 1.6 vs 2.6 ± 2.3; P < 0.01). A low basal impairment is associated with a better outcome. Improvement was obtained in both NMO-IgG negative and positive NMO attacks. Minor adverse events manifested in seven PE sessions (24%). Conclusion PE appears to be a safe add-on therapy that may be employed early in severe spinal attacks in the NMO spectrum disorders in order to maximize improvement rate. PE efficiency is independent of NMO-IgG positivity.