A new method for quantifying mfVEP signal intensity in multiple sclerosis

Abstract

Abstract The multifocal visual evoked potential (mfVEP) test measures the potentials obtained by simultaneous stimulation of multiple areas of the visual field. The principal mfVEP signal characteristics analysed are intensity and latency. A new parameter named Percentage of Energy (PoE) based on energy distribution along the recording is defined to evaluate (mfVEP) response intensity. mfVEP signals from controls and subjects classified according to the risk of developed Multiple Scleroris (MS) are used: 24 control, 15 Radiologically Isolated Syndrome (RIS), 28 Clinically Isolated Syndrome (CIS) and 28 MS diagnosed. Eyes from CIS and MS groups have been classified in neuritis optic eyes (NO) and no affected by neuritis optics eyes (nON). mfVEP signals intensity are analysed using the classic signal-to-noise (SNR) ratio and the PoE parameter. Index on discrimination between controls and different groups of diagnosed patients based on area under the curve are calculated using SNR and PoE. Lastly reproducibility test of SNR and PoE are analysed. The mean values of coefficient of variability ( C v ) for all the subjects are C VSRN = 0.34 and C VPOE = 0.17 ( p SNR = 0.79 to AUC POE = 0.83 ( p In conclusion, the PoE parameter presents advantages over the SNR parameter when characterizing mfVEP signal amplitude.