title: Pupil-sparing oculomotor nerve palsy caused by upward compression of a large posterior communicating artery aneurysm. Case report.
abstract: A 69-year-old woman without diabetes or hypertension presented with a large posterior communicating artery aneurysm projecting beneath the oculomotor nerve manifesting as a 2-week history of progressive diplopia. Neurological examination revealed external ophthalmoplegia and blepharoptosis without pupil involvement. Neuroimaging showed a large aneurysm in the left internal carotid artery projecting postero-inferiorly. Craniotomy and neck clipping of the aneurysm revealed the origin at the junction of the internal carotid artery and posterior communicating artery, and elevation of the oculomotor nerve. Pupil-sparing oculomotor nerve palsy is often assumed to be caused by ischemic injury such as hypertension and diabetes mellitus. Sometimes compressive lesion can cause pupil-sparing oculomotor nerve palsy with a short interval from the onset of symptoms to diagnosis. Despite the 2-week interval from the onset of symptoms, this patient presented with pupil-sparing oculomotor nerve palsy caused by compressive lesion. Involvement or sparing of the pupil is often considered to be the most important criterion in the diagnosis of isolated oculomotor nerve palsy. This unique case demonstrated that unusual compressive lesions must be taken into consideration in the diagnosis of pupil-sparing oculomotor nerve palsy.
authors.affiliation: Department of Neurosurgery, Nara Medical University, Kashihara, Nara, Japan. myasushi@naramed-u.ac.jp
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Motoyama
authors.forename: Junichi
authors.initials: J
authors.lastname: Nonaka
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Hironaka
authors.forename: Young-Soo
authors.initials: YS
authors.lastname: Park
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakase
mesh_terms: D000368:Aged; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D002941:Circle of Willis / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D019299:Decompression, Surgical / Q000295:instrumentation / Q000379:methods; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications* / Q000473:pathology* / Q000503:physiopathology; D015878:Mydriasis / Q000209:etiology* / Q000473:pathology* / Q000503:physiopathology; D019635:Neurosurgical Procedures / Q000295:instrumentation / Q000379:methods; D015840:Oculomotor Nerve Diseases / Q000209:etiology* / Q000473:pathology* / Q000503:physiopathology; D017777:Parasympathetic Fibers, Postganglionic / Q000293:injuries / Q000503:physiopathology; D011680:Pupil / Q000502:physiology; D011859:Radiography; D013525:Surgical Instruments / Q000592:standards