Age and Stimulus Dependency of Visually Evoked Cerebral Blood Flow Responses

Age and stimulus dependency of visually evoked cerebral blood flow responses.

BACKGROUND AND PURPOSE During visual stimulation, the increased metabolic demand is coupled with an increase of cerebral blood flow velocity (pCBFV) in the posterior cerebral artery (PCA). Investigation of the visually evoked flow responses (VEFR, expressed as percentage of increase from baseline pCBFV values) was suggested for different conditions of vasoneuronal disorders in the absence of an...

Age-related changes in the relationship between visual evoked potentials and visually evoked cerebral blood flow velocity response.

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 tran...

Effect of smoking cessation on visually evoked cerebral blood flow response in healthy volunteers.

BACKGROUND/AIMS In our previous study, impaired visually evoked flow velocity response was demonstrated in young chronic smokers. Our aim was to study whether impaired cerebrovascular reactivity is reversible 6-18 months after smoking cessation. METHODS Flow velocity changes, evoked by visual stimulus, were recorded in the posterior cerebral arteries in 15 smokers, 15 former smokers and 15 no...

Visually evoked dynamic blood flow response of the human cerebral circulation.

The dynamics of the metabolic mechanism that regulates cerebral blood flow was studied in 10 normal human subjects using a noninvasive transcranial ultrasonic Doppler method. Flow volume in the posterior cerebral artery, supplying the visual cortex, increased 20.2% in response to light stimulation of the retina, while flow velocity in the same artery increased 16.4%. The regulation of blood flo...

Visually evoked responses in amblyopia.