Asymmetries of total arterial supply of cerebral hemispheres do not exist

Abstract

BackgroundTotal blood supply to an organ, or its part, is proportional to its function. The aim of this project was to investigate whether there is a lateralisation of total functions of cerebral hemispheres by determining differences in the arterial blood supply to left and right cerebral hemispheres.MethodsDiameters of right and left anterior, middle and posterior cerebral arteries were measured at specific sites and cross-sectional areas calculated in 203 adult brains (51 donated and dissected brain specimens and 152 cerebral arterial Computed Tomography Angiography and Magnetic Resonance Angiography images).FindingsThe sample size was large enough to provide a power of detecting as significant differences of 4%, but neither of the average cross-sectional areas of right anterior, middle and posterior cerebral arteries were significantly different from those of the anterior, middle and posterior cerebral arteries of the left side. Furthermore, combined areas of the three right cerebral arteries were not significantly different from combined areas of the left three arteries. This clearly indicates that the blood supply into the right cerebral hemisphere is not different from that of the left cerebral hemisphere. Therefore, there is no total functional lateralisation between the two cerebral hemispheres.ConclusionBrain lateralisation, frequently discussed in the literature, does not deferentially influence the total activity levels of cerebral hemispheres.

Blood flow rate and wall shear stress in seven major cephalic arteries of humans

“…Previous studies show that flow rates are nearly identical in the left and right ICAs, but not necessarily in the VAs (Enzmann et al, ; Schöning et al, ; Sato & Sadamoto, ; van Ooij et al, ; Zhao et al, ). This aligns well with measurements of the nearly equal sizes of unpressurised cerebral arteries in the two hemispheres (Burlakoti et al, , ). Importantly, the ICA supplies the ACA and the MCA that service most of the cerebral cortex.…”

Stability of OCT and OCTA in the Intensive Therapy Unit Setting

“…In the posterior cerebral circulation, flow velocity and volume measured by Doppler sonography were greater in the left vertebral artery than the right (p < 0.05 for both) in a study size of 180 healthy volunteers [37]. However, in the anterior circulation, crosssectional blood flow and artery size, assessed by doppler ultrasound, computed tomography and magnetic resonance angiography in a sample size of 152 live adult patient brains, and by digital Vernier calliper measurements in 51 adult donated brains dissected out from human bodies, did not differ between right and left common carotid, anterior, middle, and posterior cerebral arteries [38].…”

Unilateral Relapsing Primary Angiitis of the CNS

“…Also, no significant difference in total arterial supply between the 2 hemispheres exists according to the best available evidence. 4 Granted, no immunologic study of the difference between the 2 cerebral hemispheres in arterial wall antigenic structure has been conducted. We did find that 2 of the 7 cases showed hemisphere asymmetry of arterial caliber size, although in 1 case, the diseased hemisphere showed smaller vessels, whereas the opposite was true in the other.…”

“… 3 Moreover, evidence of asymmetries of total arterial supply between the right and left brain is, similarly, lacking. 4 These data render a readily available explanation for chronic or relapsing asymmetric brain disease difficult to ascertain. In large case series reporting on PACNS, relapsing vasculitis in only 1 hemisphere is not described.…”