Effect of smoking cessation on visually evoked cerebral blood flow response in healthy volunteers.
OBJECTIVE
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 nonsmokers. The stimulation protocol consisted of 10 cycles with a resting phase of 20 s (baseline) and a stimulating phase of 40 s for each cycle. Relative changes of flow velocity were expressed in relation to baseline. Breath holding index, visual evoked potential and intima-media thickness were also examined.


RESULTS
Repeated measures ANOVA revealed marked difference in the flow velocity time courses between the 3 groups (p < 0.01). The flow response was significantly worse in former smokers than in nonsmokers (p < 0.002), however, no significant difference was found between former and current smokers (p = 0.0556).


CONCLUSIONS
This is the first transcranial Doppler study demonstrating long-term impairment of visually evoked cerebrovascular response after smoking cessation. These findings indicate that the impairment of neurovascular coupling caused by smoking is due to structural changes of the vessels, rather than acute effect of smoking.
Boms
Neta
N
Department of Neurology, University of Debrecen, Debrecen, Hungary.
Yonai
Yaniv
Y
Molnar
Sandor
S
Rosengarten
Bernhard
B
Bornstein
Natan M
NM
Csiba
Laszlo
L
Olah
Laszlo
L
D000328:Adult; D001783:Blood Flow Velocity; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging; D002560:Cerebrovascular Circulation; D005074:Evoked Potentials, Visual; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D020769:Posterior Cerebral Artery / Q000000981:diagnostic imaging / Q000294:innervation / Q000503:physiopathology*; D020127:Recovery of Function; D015656:Respiratory Mechanics; D012907:Smoking / Q000009:adverse effects*; D016540:Smoking Cessation; D013997:Time Factors; D017585:Ultrasonography, Doppler, Transcranial; D014664:Vasodilation; D014795:Visual Pathways / Q000503:physiopathology*; D055815:Young Adult