Neuromyelitis optica in Brazil: a study on clinical and prognostic factors

To describe the clinical characteristics of patients with relapsing neuromyelitis optica (NMO) from a tertiary care center in Brazil and compare the groups with normal and abnormal brain magnetic resonance imaging (MRI).

Retrospective review of 41 patients followed at the Neuroimmunology Clinic of the Federal University of São Paulo, Brazil, from 1994 to 2007.

All patients had relapsing-remitting optic-spinal disease, long extending spinal cord lesions, and brain MRI not meeting Barkhof criteria for multiple sclerosis (MS), thus fulfilling the 1999 and 2006 Wingerchuck criteria for NMO. Mean follow-up time was 52 months; mean age of onset was 32.6 years. The mean relapse rate (RR) and progression index (PI) were 1.0 and 0.9, respectively. Twenty-four patients had brain lesions not compatible with MS on MRI, and there were no statistical differences on PI and RR between patients who had brain lesions and patients who did not. Incomplete recovery, but not the type of first relapse, correlated with a worse prognosis. Seventeen patients were tested for NMO-IgG (anti-aquaporin-4 antibody) with 41% positivity.

In this series, we did not find a statistical difference of disease progression between patients with and without brain lesions, suggesting that the presence of brain abnormalities is not a marker of disease severity.