title: [Rupture of an internal carotid-posterior communicating artery aneurysm formerly presented with transient pupil-sparing oculomotor nerve palsy in an extremely elderly patient].
abstract: We recently encountered experienced a rare case of transient pupil-sparing oculomotor nerve palsy(PSONP)caused by an aneurysm at the junction of the internal carotid-and posterior communicating arteries(IC/PC AN)in an 87-year-old, non-diabetic woman. She initially presented with diplopia 4 years previously, and was diagnosed, based on incomplete right oculomotor paresis without pupil involvement(PSONP), as external ophthalmoplegia. MR-angiography revealed a long protrusion of the IC/PC AN with posterior-inferior projection, for which she chose to receive conservative management. Thirty nine months later, she presented with another transient PSONP. CT angiography(CTA)showed that the aneurysm was enlarged in the posterior-inferior direction. Two days after this last CTA imaging, the aneurysm ruptured with upward enlargement of the bleb. Despite complete external ophthalmoplegia and ptosis, her pupil involvement was still minimal and transient. By reviewing reported cases and our own case, we found that a narrow and long aneurysm body and posterior-inferior projection are characteristic for the IC/PC AN that causes PSONP, implying a possible mechanism for PSONP by upward compression of the oculomotor nerve. Though rare in its incidence, IC/PC AN could present with PSONP prior to their rupture. Therefore, immediate imaging evaluation in patients presenting with PSONP is essential to prevent devastating rupture events.
authors.affiliation: Residency Program, National Hospital Organization Nagasaki Medical Center.
authors.forename: Toma
authors.initials: T
authors.lastname: Mijin
authors.forename: Keisuke
authors.initials: K
authors.lastname: Tsutsumi
authors.forename: Takashi
authors.initials: T
authors.lastname: Fujimoto
authors.forename: Hideaki
authors.initials: H
authors.lastname: Takahata
authors.forename: Ichiro
authors.initials: I
authors.lastname: Kawahara
authors.forename: Tomonori
authors.initials: T
authors.lastname: Ono
authors.forename: Keisuke
authors.initials: K
authors.lastname: Toda
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Baba
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yonekura
mesh_terms: D000369:Aged, 80 and over; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000473:pathology*; D004621:Embolization, Therapeutic; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000628:therapy; D009802:Oculomotor Nerve / Q000000981:diagnostic imaging / Q000473:pathology*; D015840:Oculomotor Nerve Diseases / Q000000981:diagnostic imaging / Q000209:etiology*; D011680:Pupil / Q000502:physiology*; D011859:Radiography; D012421:Rupture / Q000150:complications / Q000000981:diagnostic imaging; D016896:Treatment Outcome