Abstract Details

We aimed in this study to assess the role of VEP in enhancing the diagnostic accuracy of MS and NMSD, early in the disease course.

We retrospectively reviewed patients with MS and NMDSD seen between 2015 and 2020. We identified patients’ demographics, first presentation, MRI disease activities, serum and CSF immune markers, and VEP data.

We included 232 patients; the mean age was 37 years (range; 15-68 years), and the mean disease duration was 9 years (range; 1-42 years). VEP was abnormal in 159 (69 %), with no patterns distinguishing MS from NMODS, apart from the significantly documented axonal features in NMDS (table 1, figure 1). Transverse myelitis (TM) was 2 times more likely to be the first presentation in NMODS (OR=2.3, p-value =0.01, 95 % CI; 1.2, 4.4). Furthermore, patients presented initially with TM, who had P100 wave latency longer than 116 ms, were 2.5 times more likely to have NMODS (OR= 2.5, p-value <0.01, 95 % CI; 1.2 – 4.9). On the other hand, the odds of NMODS were 3 times in patients presented with TM with a P100 latency difference of 10 ms or more between both responses (OR= 3.2, p-value <0.01, 95 % CI; 1.4 – 7.4). Multivariate regression analysis confirmed these observations (Table 2). P100 wave latency had no added value in early differentiation of MS and NMODS with other clinical presentations early in the disease, including optic neuritis (ON).

P100 wave latency can significantly discriminate NMOSD from MS, and along with TM, it increased the yield to confirm NMOSD early in the disease course. These findings suggest a high diagnostic yield for this non-invasive diagnostic tool.