Brain abnormalities as an initial manifestation of neuromyelitis optica spectrum disorder

Although brain abnormalities are being recognized more frequently in patients with neuromyelitis optica spectrum disorder (NMOSD), most brain lesions in previous reports have accompanied pre-existing NMOSD. Here, we describe clinical and imaging characteristics of patients with NMOSD who presented with brain symptoms as their first manifestation of the condition.

Anti-aquaporin-4 antibody was measured using cell-based assays and/or enzyme-linked immunosorbent assay in the sera of 257 patients with inflammatory diseases of the central nervous system who attended the multiple sclerosis clinic of the National Cancer Center, Korea, between May 2005 and December 2009. Eighty-three were seropositive, and 15 of these who presented with brain symptoms were included in this study. We retrospectively reviewed these individuals' clinical and radiological findings.

Patients with NMOSD were followed for a mean of 90 months. Median age at onset was 24 years (6-54 years) and there was a female preponderance (94%). The initial manifestation was classified into two groups according to clinical characteristics: encephalopathy mimicking acute disseminated encephalomyelitis or posterior reversible encephalopathy syndrome and characteristic brainstem symptoms such as intractable hiccup and vomiting. The majority of brain symptoms and lesions resolved. Intriguingly, eight patients (53%) experienced brain relapses that followed a similar pattern during the course of their disease.

It is important to recognize that NMO or NMOSD can initially present with brain symptoms.