Neuromyelitis optica spectrum disorder in a tertiary hospital in the Philippines: a case series.

Neuromyelitis optica spectrum disorder (NMOSD) is a rare disease that commonly presents with optic nerve and spinal cord inflammation, and it is associated with the presence of aquaporin-4 immunoglobulin G antibody (AQP4-IgG). Information on the clinical profile and occurrence of NMOSD among Filipino patients, however, is not sufficiently documented. In this series, we presented eighteen (18) patients with NMOSD consecutively seen in the Philippine General Hospital, a major tertiary referral center. Demographic data showed a female-to-male ratio of 2.6:1. Median age of onset of symptoms was 26 years. Eight patients (53.3%) were positive for AQP4-IgG. Most patients initially presented with myelitis (56.6%) and followed by optic neuritis (16.7%) and area postrema syndrome (16.7%). All patients had longitudinally extensive transverse myelitis on magnetic resonance imaging (MRI). Cranial MRI rarely demonstrated lesions in the optic nerves (18.2%). CSF pleocytosis (33%) and increased protein (8.3%) were infrequent. These results demonstrated that the profile of Filipino patients with NMOSD seen in our institution strengthens those described in other populations with this disorder. Large scale cross-sectional studies are necessary to fully define the profile of these patients and to determine with accuracy the prevalence and incidence of this disorder in the Philippines. Further investigation regarding the utility of ancillary tests as diagnostic and prognostic indicators in patients with NMOSD are also suggested by the authors.