Purpose
A lot of patients after cerebral MR-angiography, get a conclusion about one or even several circle of Willis (COW) anatomical variants. Can this diagnosis explain their disorder? Do they need to observed by a neurologist further? And are COW variant abnormalities and can they lead to changes in the brain?
There is no unified concept about the normal COW. Radiological reportscontain such ambiguous terms as: "open COW" or "fetal COW". In our study and a small literary review, we tried to clarify the issues of...
Methods and materials
71 patients 03.02.19-25.09.19 examined by brain MRI+angiography according to protocol [1]:
Neuro MR-protocol:
• axial T2 spin-echo
• axial T2 fluid-attenuated inversion recovery (FLAIR)
• sagittal T2 fast-spin-echo (FSE)
• coronal T1 FLAIR
• 3D time-of-flight (TOF) gradient-echo (GRE)
Liquor spaces, reflecting the degree of atrophic changes were measured in each patient (fig 1).
Cerebral measurements parameters:
• Cerebral atrophy: maximal width of convex sulcus on Ax T2 + parietal space on Sag T2 (mm).
• Cerebellar atrophy: maximal width of cerebellar sulcus + сerebellopontine...
Results
Review
There are many scientific concepts of normal COW [2]. Lack of posterior communication arteries (Pcomm) visualization on MR-angiography in some publications considered as aplasia. Others believe that their diameter so small that blood flow is not visible [3, 4].
Studies relating to the posterior COW (Pcomm and firstposterior cerebral arteries segment P1) actively discuss periods of their formation [5]. Embryological studies generally distinguish three types of embryo circulation:
Fetal - in which posterior cerebral artery (PCA) mostly derives from Internal Carotid Artery (ICA)
Transitional...
Conclusion
Cerebral arteries anatomical variants cannot lead to cerebral atrophy, focal vascular brain changes.
The lack of visualization of the Pcomm arteries is a normal version of the COW structure and cannot be attributed to open COW variant that can only be first segments of ACA and PCA aplasia.
Anterior or posterior COW and VA variants can be combined and complement each other.
Having one or more anatomical variants of cerebral blood supply can increase headache the number of neurological complaints and generally affect the overall...
Personal information and conflict of interest
J. Sidorova; Moscow/RU - nothing to disclose A. Gromov; Moscow/RU - nothing to disclose A. Kudryavtseva; Moscow/RU - nothing to disclose M. Starodubtseva; Moscow/RU - nothing to disclose
References
Mikulis DJ. Roberts TP. Neuro MR: Protocols. Journal of magnetic resonance imaging 2007;26:838–847.
Reddy Ravikanth. Babu Philip. Magnetic resonance angiography determined variations in the circle of Willis: Analysis of a large series from a single center. Tzu Chi Medical Journal 2019;31(1): 52–59. DOI: 10.4103/tcmj.tcmj_167_17.
Gunnal SA, Farooqui MS, Wabale RN. Anatomical variability of the posterior communicating artery. Asian J Neurosurg. 2018;13:363-9. http://www.asianjns.org IP: 185.190.122.77
Krishnaswamy A, Klein JP, Kapadia SR. Clinical cerebrovascular anatomy. Catheter Cardiovasc Interv. 2010 Mar 01;75(4):530-9. PubMed: 20049963
Khaled Menshawi, Jay P...