Descriptive statistics of serum GFAP measurements (pg/mL) in patients across all categories3 are shown.

The fifth column shows the merged data of all ‘non-NMO spectrum’ patients. Both mean and median values for the serum GFAP level were highest in the NMO spectrum category and lowest in the MS related ON category. The results from patients with ‘atypical’ patterns of optic neuritis (‘RION’ and ‘CRION’ pattern) fell halfway between the two groups. Patients in the NMO spectrum group showed the highest variance. All values are stated to within 2 decimal places.1Std Dev = standard deviation.2C.I. = Confidence Interval.3ON = optic neuritis, AQP4+ON = Aquaporin 4 autoantibody positive ON, ‘CRION’ = ‘chronic relapsing inflammatory optic neuropathy’, ‘RION’ = Recurrent Isolated Optic Neuritis.