Analysis of Neuromyelitis Optica Spectrum Disorder in an Indian Cohort using International Consensus Diagnostic Criteria

Context: Updates on clinical, investigatory, and therapeutic aspects of neuromyelitis optica (NMO) spectrum disorders are rapidly evolving. Recently published international consensus diagnostic criteria (ICDC) allowed clinicians to rapidly diagnose the expanding spectrum of NMO spectrum disorders more accurately. Aims: The aim of the study was to retrospectively analyze 36 consecutive cases of comprehensively evaluated NMO spectrum disorders using the ICDC. Patients and Methods: We retrospectively collected 36 cases of NMO spectrum disorders who attended our unit between August 2012 andOctober 2016 and fulfilled the ICDC. All patients underwent magnetic resonance imaging (MRI) of the brain and whole spine with contrast, anti-aquaporin 4 antibody, and detailed blood investigations to rule out systemic vasculitis and other alternate diagnoses. Results: Female-to-male ratio was 6.2:1; 50% of the cases were in the 20-40-year age group. Six patients (16.67%) had combined optic neuritis and myelitis.Nine patients (25%) had pure longitudinally extending transverse myelitis LETM with positive anti aquaporin 4 antibody AQ4Ab. Fourteen patients (38.9%) had myelitis and optic neuritis separately. Nine patients (25%) had area postrema syndrome. Two patients (5.6%) had acute brainstem syndrome and one (2.8%) had hypothalamic syndrome. LETM was commonly found in the cervical level (69.4%).Four patients (11.1%) had no spinal cord involvement. Anti-aquaporin 4 antibody was positive only in 23 cases (63.9%). Conclusions: Initial presentation of NMO spectrum disorder is often due to brain lesions. The ICDC criteria have enhanced clinician's ability to diagnose NMO spectrum disorder in the early stages. In our study, ICDC criteria helped us to diagnose 33% additional cases that would have been missed if the old 2006 revised criteria was applied.