Sestre Milosrdnice University hospital and Institute of Clinical Medical Research
Abstract
Changes of mean blood flow velocities (MBFV) in the posterior cerebral arteries (PCA) during visual stimulation were recorded in a group of 51 healthy, right-handed volunteers. There were 27 (52.9%) males and 24 (47.1%) females aged from 20 to 59 (mean age 36.98) years. Measurements were performed with a hand-held 2 MHz transcranial Doppler (.I.CD) probe through temporal window, while the subjects had their eyes open, closed, and when looking at white light. In half of the subjects, the right PCA was insonated first and then the left PCA, while in the other half a reverse procedure was used. Statistical analysis was performed using Wilcoxon.s matched-pair signed-rank test. In the left PCA, MBFV was 41.2±8.6 cm/s (mean ± SD) with eyes open, 27.8±8.5 cm/s with eyes closed, and 42.3±9.1 cm/s while looking at white light. In the right PCA, MBFV was 41.7±8.9 cm/s with eyes open, 28.2±9.1 cm/s with eyes closed, and 42.4±8.8 cm/s while looking at white light. In the left PCA, differences between eyes open and closed, and between eyes open and while looking at white light were statistically significant (p<0.001, z=-6.2146, and p<0.001, z=-3.4836, respectively). In the right PCA, a statistically significant difference was found between eyes open and closed (p<0.001, z=-6.2146 and p<0.001, z=-3.6928), but not between eyes open and looking at white light (p=0.03, z=-2.1693). Study results demonstrated that straightforward visual stimulation had an effect on blood flow velocities in PCA and that it could be measured with TCD.Promjene srednjih brzina krvnog protoka (MBFV) u stražnjim moždanim arterijama (PCA) bilježene su tijekom vidne stimulacije u skupini od 51 zdravog desnorukog dobrovoljca. Skupina se sastojala od 27 (52,9%) muških i 24 (47,1%) ženskih ispitanika u dobi od 20 do 59 (srednja dob 36,98) godina. Mjerenja su se izvodila pomoću ručne sonde od 2 MHz za transkranijski Doppler (TCD) kroz temporalni prozor, dok su ispitanici oči držali otvorenima, zatvorenima i dok su gledali u bijelo svjetlo. U polovice ispitanika najprije je ispitana desna PCA, a potom lijeva PCA, a u druge polovice primijenjen je obrnuti postupak. Statistička analiza je provedena pomoću Wilcoxonova parnog rank testa. U lijevoj PCA je MBFV bila 41,2±8,6 cm/s (srednja vrijednost ± SD) uz otvorene oči, 27,8±8,5 cm/s uza zatvorene oči i 42,3±9,1 cm/s dok su gledali u bijelo svjetlo. U desnoj PCA je MBFV bila 41,7±8,9 cm/s uz otvorene oči, 28,2±9,1 cm/s uza zatvorene oči i 42,4±8,8 cm/s dok su gledali u bijelo svjetlo. Razlike u MBFV između zatvorenih i otvorenih očiju, te između otvorenih očiju i gledanja u bijelo svjetlo bile su statistički značajne za lijevu PCA (p<0,001, z=-6,2146, odnosno p<0,001, z=-3,4836). U desnoj PCA je razlika u MBFV bila statistički značajna između otvorenih i zatvorenih očiju (p<0,001, z=-6,2146, odnosno p<0,001, z=-3,6928), ali ne između otvorenih očiju i gledanja u bijelo svjetlo (p=0,03, z=-2,1693). Rezultati su pokazali da izravna vidna stimulacija utječe na brzinu krvnog protoka u PCA te da se to može mjeriti pomoću TCD
