Middle cerebral artery aneurysm epidemiology

Middle cerebral artery aneurysms, represent almost a third of all the intracranial aneurysms of the anterior circulation aneurysms. 18-40% of all intracranial aneurysms 1).

Among them, those located at M1 segment of the middle cerebral artery (from its origin up to the bifurcation) range between 2% and 7% of all the aneurysms.

Most MCA aneurysms have been found at the division of the M1-M2 junction due to hemodynamic stress or congenital factors 2).

Only in 1.1-1.7% of cases they are located in the distal segment 3) 4) 5).

The majority of distal MCA aneurysms are located at the M2 or M3 segments 6).

References

1) , 5)
Elsharkawy A, Lehečka M, Niemelä M, Billon-Grand R, Lehto H, Kivisaari R, Hernesniemi J. A new, more accurate classification of middle cerebral artery aneurysms: computed tomography angiographic study of 1,009 consecutive cases with 1,309 middle cerebral artery aneurysms. Neurosurgery. 2013 Jul;73(1):94-102; discussion 102. doi: 10.1227/01.neu.0000429842.61213.d5. PubMed PMID: 23615110.
2)
Rinne J, Hernesniemi J, Niskanen M, Vapalahti M. Analysis of 561 patients with 690 middle cerebral artery aneurysms: anatomic and clinical features as correlated to management outcome. Neurosurgery. 1996 Jan;38(1):2-11. PubMed PMID: 8747945.
3)
Ahn JY, Han IB, Joo JY. Aneurysm in the penetrating artery of the distal middle cerebral artery presenting as intracerebral haemorrhage. Acta Neurochir (Wien). 2005 Dec;147(12):1287-90; discussion 1290. Epub 2005 Aug 29. PubMed PMID: 16133768.
4)
Lv N, Zhou Y, Yang P, Li Q, Zhao R, Fang Y, Xu Y, Hong B, Zhao W, Liu J, Huang Q. Endovascular treatment of distal middle cerebral artery aneurysms: Report of eight cases and literature review. Interv Neuroradiol. 2016 Feb;22(1):12-7. doi: 10.1177/1591019915617317. Epub 2015 Dec 3. Review. PubMed PMID: 26637241; PubMed Central PMCID: PMC4757379.
6)
Lee SH, Bang JS. Distal Middle Cerebral Artery M4 Aneurysm Surgery Using Navigation-CT Angiography. J Korean Neurosurg Soc. 2007 Dec;42(6):478-80. doi: 10.3340/jkns.2007.42.6.478. Epub 2007 Dec 20. PubMed PMID: 19096593; PubMed Central PMCID: PMC2588183.