Internal Carotid Artery / Posterior Communicating Artery Aneurysm with Third Nerve Palsy Shown on CT Angiogram

Internal Carotid Artery / Posterior Communicating Artery Aneurysm with Third Nerve Palsy Shown on CT Angiogram ; anatomic description of vascular and bony findings on the CTA. - Figure 1 : 51 year-old man complaining of painful binocular diplopia. Orange arrows indicate the direction of gaze. In primary position, he has a left ptosis and a left exotropia. Ocular motor examination shows left adduction, elevation, and depression deficits. He has a left mydriasis. Abduction and intorsion of the left eye are normal. Examination is consistent with an isolated complete left third nerve palsy with pupillary involvement. - Figure 2 : 3D post-processing CTA - Endocranial view of the Willis circle - Figure 3 : 3D post-processing CTA - Endocranial view of the bones - Figure 4 : CTA, axial cut showing the location of the aneurysm relative to the left internal carotid and the left middle and posterior cerebral arteries - Figure 5 : CTA, coronal cut showing the location of the aneurysm relative to the left posterior cerebral artery and the left superior cerebellar artery.