title: Functional assessment of the visual pathway with multifocal visual evoked potentials, and their relationship with disability in patients with multiple sclerosis.
abstract: OBJECTIVE
  To objectively evaluate the visual function, and the relationship between disability and optic nerve dysfunction, in patients with multiple sclerosis (MS) and optic neuritis (ON), using multifocal visual evoked potentials (mfVEP).
  
  
  METHODS
  This observational, cross-sectional study assessed 28 consecutive patients with clinically definite MS, according to the McDonald criteria, and 19 age-matched healthy subjects. Disability was recorded using the Expanded Disability Status Scale (EDSS) score. The patients' mfVEP were compared to their clinical, psychophysical (Humphrey perimetry) and structural (optic coherence tomography (OCT)) diagnostic test data.
  
  
  RESULTS
  We observed a significant agreement between mfVEP amplitude and Humphrey perimetry/OCT in MS-ON eyes, and between mfVEP amplitude and OCT in MS but non-ON eyes. We found significant differences in EDSS score between patients with abnormal and normal mfVEP amplitudes. Abnormal mfVEP amplitude defects (from interocular and monocular probability analysis) were found in 67.9% and 73.7% of the MS-ON and MS-non-ON group eyes, respectively. Delayed mfVEP latencies (interocular and monocular probability analysis) were seen in 70.3% and 73.7% of the MS-ON and MS-non-ON groups, respectively.
  
  
  CONCLUSIONS
  We found a significant relationship between mfVEP amplitude and disease severity, as measured by EDSS score, that suggested there is a role for mfVEP amplitude as a functional biomarker of axonal loss in MS.
authors.affiliation: University of Alcalá, Madrid, Spain.
authors.forename: Román
authors.initials: R
authors.lastname: Blanco
authors.forename: Consuelo
authors.initials: C
authors.lastname: Pérez-Rico
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Puertas-Muñoz
authors.forename: Lucía
authors.initials: L
authors.lastname: Ayuso-Peralta
authors.forename: Luciano
authors.initials: L
authors.lastname: Boquete
authors.forename: Juan
authors.initials: J
authors.lastname: Arévalo-Serrano
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009103:Multiple Sclerosis / Q000473:pathology* / Q000503:physiopathology*; D014795:Visual Pathways / Q000473:pathology* / Q000503:physiopathology*
keywords: Expanded Disability Status Scale; multifocal visual evoked potentials; multiple sclerosis; optic nerve; optic neuritis; optical coherence tomography; perimetry; visual function