MULTIPLE SCLEROSIS AND NEUROMYELITIS OPTICA: ANALYSIS OF MULTIFOCAL VISUAL EVOKED POTENTIALS

Abstract

Purpose: To compare the reliability indexes multifocal visual evoked potentials (mfVEP) in patients with multiple sclerosis (MS) and neuromyelitis optica (NMO).

Methods: Patients with multiple sclerosis (9 subjects, 18 eyes, 37 ± 9.7 years old) and NMO (12 subjects, 20 eyes, 36.1 ± 11.8 years old) were studied by biomicroscopy, fundoscopy, visual acuity and visual electrophysiology (mfVEP). mfVEP was recorded using Veris 6010 system with 60 sectors black and white. We estimated the signal-to-noise ratio (SNR) for each form of mfVEP wave. The mfVEP waveforms were reliable when the SNR was greater than 1.395. Moreover , the rates of reliable forms of wave mfVEP was quantified as the ratio between the number of waveforms confidence / total number of sectors of six areas of the same eccentricity (from inside the visual field R1 to R6 in exterior visual field ) and the whole visual field. We used the binomial test, α = 0.05 as analysis.

Results: Optic neuritis (ON) was present in 5/18 eyes of patients with multiple sclerosis and 9/ 20 patients NMO. Confidence indices of mfVEP for the controls were higher than for the MS with or without ON and NMO with ON in R1 - R5. In R6, the control rate was higher than the rate for all other groups of patients. The rate of mfVEP to reliably controls were higher than those obtained for the MS and ON with or without NMO MS (p < 0.01) in R1 - R5. In R6, the control rate was higher than the rate for all other groups of patients. The rate of mfVEP reliable for NMO group was higher than the rate of set of MS, despite the presence of NO. The rate waveform to trust the MS group without ON was higher than for the MS group with ON (p<0.01), and there was no difference between NMO group with and without ON for all analyzed areas.

Conclusions: The rate of reliability mfVEP wave was the lowest among MS patients and the presence of ON significantly decreased the performance of patients with MS and NMO ways to generate reliable mfVEP wave.

Keywords: 507 electrophysiology: clinical • 613 neuro-ophthalmology: optic nerve • 629 optic nerve