Validation of the 2015 diagnostic criteria for neuromyelitis optica spectrum disorders in a cohort of South Indian patients.

Background: Neuromyelitis Optica spectrum disorders (NMOSD) are one of the most common CNS demyelinating disorders as they will present with disabling recurrent demyelinating attacks. Hence, it is of paramount importance to diagnose early, and early diagnoses and intervention will prevent further relapses associated with NMOSD. New international consensus criteria have been proposed and studies validating its application towards diagnoses of NMOSD in south Asian population are meagre. Hence we validated the proposed International Panel for NMO Diagnosis (IPND), 2015 criteria to study the clinical, demographic profile and sero-status of patients who are presenting with core clinical symptoms of NMOSD in South India and compare it with 2006 criteria.

Methods: A retrospective study was conducted in a tertiary hospital for a period of one year. Patients who had at least one core clinical feature of NMOSD were included. Demographics and clinical data were recorded and analysed. Cases were evaluated using 2015 IPND and 2006 criteria for all patients, data was analysed using SPSS.

Results: A total of 110 patients were included and 91(82.72%) patients fulfilled IPND 2015 criteria. Out of 91 patients, 70 patients were AQP4 antibody positive and 21 were negative. Out of 110, only 30 (27.2%) satisfied 2006 criteria (24 or 80% were seropositive). 2015 criteria were more sensitive in identifying 61 new NMOSD cases juxtaposed to 2006 criteria, this difference was statistically significant (P<0.05).

Conclusion: The 2015 IPND criteria were more sensitive and specific than previous 2006 criteria as it covered diverse clinical manifestations of NMOSD. Applying this criteria, NMOSD could be diagnosed among patients with monophasic illness, isolated recurrent optic neuritis, isolated recurrent myelitis, cerebral syndrome, diencephalic syndrome, brainstem syndrome and area postrema syndrome, thus improving the diagnostic yield.