title: Age-related changes in the relationship between visual evoked potentials and visually evoked cerebral blood flow velocity response.
abstract: We evaluated neurovascular coupling during normal aging using visual evoked potentials (VEPs) and visually evoked cerebral blood flow velocity responses (VEFRs). The recordings were made from a group of healthy younger and older subjects. The stimulus was a black and white checkerboard with visual contrasts of 1%, 10% and 100%. The VEFRs were measured in the posterior cerebral artery using transcranial Doppler simultaneously with VEPs from occipital leads. A significant increase in the VEFRs and VEPs in response to graded visual contrasts (p<0.01) was found in both groups. Linear regression analysis showed a significant positive association between the VEPs and the VEFRs in the younger (r=0.66, p<0.01) and older subjects (r=0.74, p<0.01). We also found significant differences in neurovascular coupling index (VEFR/VEP) between both groups at each visual contrast (p<0.01). We conclude that simultaneous recording of VEFRs and VEPs at graded visual contrasts indicated attenuated neurovascular coupling in older subjects.
authors.affiliation: Department of Neurology, Ljublijana University Medical Centre, Slovenia. marjan.zaletel@kclj.si
authors.forename: Marjan
authors.initials: M
authors.lastname: Zaletel
authors.forename: Martin
authors.initials: M
authors.lastname: Strucl
authors.forename: Janja
authors.initials: J
authors.lastname: Pretnar-Oblak
authors.forename: Bojana
authors.initials: B
authors.lastname: Zvan
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D002540:Cerebral Cortex / Q000098:blood supply* / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D015350:Contrast Sensitivity / Q000502:physiology*; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values