A Study Of Variations In The Origin Of Superior Cerebellar Artery And The Dimensions Of Its Proximal Segment

ABSTRACT

Background: Since many clinical conditions affecting the brain stem are the results of vascular lesions, profoundknowledge of vertebrobasilar circulation is of utmost clinical importance.Variations in the origin of superiorcerebellar artery(SCA) are frequently observed and these may play an important role in neurovascular compressionsyndrome, as III,IV and V cranial nerves are closely related to SCA. Being one of the frequent locations foraneurysms of posterior circulation,variations of SCA should be considered prior to any diagnostic or therapeuticprocedures in basilar tip region.Materials and Methods: The current study was conducted on 80 human cadaveric brain specimens to study thevariant origin of superior cerebellar artery, its anomalies, and to measure the dimensions of proximal segmentof SCA. The study was undertaken during routine dissection for the undergraduate students over a period of 5years.Results: 80 specimens, (i.e. 160 SCAs) were analysed. SCA arose from the basilar artery in 152 cases. In 3 casesSCA originated from posterior cerebral artery(PCA). SCA and PCA arose as common trunk in 5 cases.Out of 160SCAs, it arose as a single vessel in 129 cases. Duplication was seen in 28 cases. Triplication was found in 3 cases.Outer diameter of SCA at its origin was 1.8 ±0.5mm on the right side. On the left side it was 1.6 ±0.4mm.The lengthof the proximal segment of the SCA ranged from 9 to 24mm. The distance between SCA and PCA ranged from 0.6mmto 3.2mm.Conclusion: Our study identified significant variations in the origin of SCA as well as the dimensions of itsproximal segment. It would be useful for neuroradiologists in investigative procedures like CT, MRI and cerebralangiography. Neurosurgeons performing endovascular procedures for aneurysms and surgery for posteriorfossa tumors will also benefit from this study.