Minimosymptomatic occlusion of the middle cerebral artery

Minimosymptomatic occlusion of the MCA before the origin of the perforating branches is an exceedingly rare occurrence. We report two cases of MCA occlusion at its origin, the second case proven by the CT scan in vivo. Published work rules out the possibility of a functionally effective deep collateral circulation in the distribution of the capsular rami of the MCA. In view of this we argue that there may be cases - admittedly very rare - in which, given the individual variability of the vascular supply, the MCA may be of negligible functional importance to the circulation of the internal capsule. In such cases occlusion of the MCA would be relatively well tolerated.