Equiluminant red-green and blue-yellow VEPs in multiple sclerosis

F. Sartucci, L. Murri, C. Orsini, V. Porciatti

Research output: Contribution to journalArticlepeer-review

26 Scopus citations


The primate visual system is composed by two color-opponent pathways-red-green (R-G) and blue-yellow (B-Y)-subserved by the so-called parvo- and koniocellular streams respectively. The authors' aim was to compare the relative involvement of chromatic visual subsystems in multiple sclerosis (MS). In 30 MS patients with different forms of MS they recorded visual evoked potentials (VEPs) to onset (300 msec) and offset (700 msec) of equiluminant R-G and B-Y sinusoidal gratings of different contrast (90% and 25%). Equiluminance was established psychophysically by establishing the R-G and the B-Y color ratio at which chromatic gratings alternating at 15 and 10 Hz respectively had minimum visibility. The negative wave at stimulus onset with a peak latency of 120 to 160 msec was evaluated. Ordinary VEPs to luminance (LUM) contrast (black-white reversing checkerboards of 15' check size and 50% contrast) were also recorded for comparison. Latencies of R-G VEPs were abnormal in 53.3% and 58.3% of patients at 90% and 25% contrast respectively, whereas abnormal B-Y VEPs were 56.6% and 48.3%. Latencies of LUM VEPs were abnormal in 45% of patients. Interocular latency asymmetries were abnormal in 59.2% and 33.3% of patients for R-G, and 51.8% and 62.9% for B-Y, Latency asymmetries for LUM VEP were abnormal in 46.4% of patients. The higher rate of VEP abnormalities found with equiluminant chromatic stimuli compared with achromatic stimuli confirms the general vulnerability of color-opponent visual pathways in MS, even if the number of patients with abnormal findings was not significantly different when both test conditions were compared. VEPs to R-G and B-Y equiluminant stimuli appear to be involved approximately to the same extent.

Original languageEnglish (US)
Pages (from-to)583-591
Number of pages9
JournalJournal of Clinical Neurophysiology
Issue number6
StatePublished - Jan 1 2001
Externally publishedYes


  • Chromatic contrast
  • Koniocellular system
  • Magnocellular system
  • Multiple sclerosis
  • Parvocellular system
  • VEPs

ASJC Scopus subject areas

  • Clinical Neurology
  • Physiology
  • Neuroscience(all)


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