Clinicoradiologic profile of neuromyelitis optica spectrum disorder in a Kashmiri cohort: a prospective observational cohort study.

Purpose: Neuromyelitis optica spectrum disorder (NMOSD) is a rare disease that is often misdiagnosed and that can have ethnic variations. No prior study of this condition in a Kashmiri cohort has been reported, which motivated this study. Methods: This prospective, observational cohort study included 32 patients. NMOSD was diagnosed according to the International Panel for NMO Diagnosis criteria based on serology, magnetic resonance imaging (MRI), cerebrospinal fluid (CSF), and visual evoked potential (VEP) findings. Results: Among central nervous system demyelinating diseases, NMOSD constituted 20.3% of cases, with a frequency second only to multiple sclerosis. Mean age at presentation was 39 years with 78%of patients being females.90.6% were positive for aquaporin 4 (AQP4) autoantibodies. Optic neuritis (ON) was seen in relatively young patients, with a mean age of presentation of 24.7 years. Presenting syndromes included transverse myelitis (TM; 46.9%), ON (21.9%), combined ON + TM (25.0%), and area postrema syndrome (6.3%). MRI scans of the brain were abnormal in 53.1% of the cohort, with abnormalities in VEP and CSF seen in 42.0 % of eyes and 78.1% of patients, respectively. Cervical cords in combination with cervicothoracic cords were the most common sites of cord involvement. Three patients among the TM patients also had spinal movement disorders. All patients received rituximab as a disease-modifying therapy. Two relapses and one mortality were documented in a one-year follow-up. Conclusion: Kashmiri NMOSD patients largely follow global patterns with a female preponderance, high AQP4 positivity, and a predominance of cervical longitudinally extensive TM. Optic Neuritis was seen in relatively younger patients. Our findings also highlight the utility of rituximab in treating NMOSD in resource-poor settings.