XXXX with preoperative improvement from a posterior communicating artery aneurysm.

@entity1 @entity2895 @entity439 @entity2443 @entity892 @entity10
BACKGROUND: Despite the plenitude of reports concerning @entity2895 , especially as presenting symptoms with posterior communicating artery (PCoA) @entity439 , we present a @entity1 with an unusual variation. CASE DESCRIPTION: A 66-year-old @entity1 presented with progressive right-sided @entity10 and @entity892 and was found to have a partial, @entity2895 . A small right-sided PCoA @entity439 , nearly indistinguishable from an infundibulum, was identified on magnetic resonance angiography and subsequent digital subtraction angiography. The @entity2895 improved before surgical repair of the @entity439 . RESULTS: Microsurgical exploration revealed a small PCoA @entity439 , which was tethered to the third nerve by @entity2443 . Adhesions were lysed and the @entity439 was repaired sparing the PCoA and its branches. The @entity1 's third nerve function recovered completely postoperatively. CONCLUSIONS: Even a very small PCoA @entity439 may present with an improving, pupil-sparing @entity2895 . Selection of @entity1 for imaging studies should take this unusual variant into consideration. We describe the anatomy and potential mechanisms of this @entity2895 .
