Presentation
Transient weakness of left lower leg.
Patient Data
Age: 50 years
Gender: Female
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M2 segment of left middle cerebral artery divides into three branches instead of two.
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3D VRT of cerebral MR angiography shows trifurcated M2 segment left middle cerebral artery.
Case Discussion
The commonest pattern (around 80%) of branching of the MCA is by bifurcation of the M2 segment into superior and inferior divisions. About 10% make trifurcations and another 10% split into more than three branches 1. One implication of such branching patterns is that the point of division is prone to aneurysms and pseudoaneurysms.