title: A review of isolated third nerve palsy without subarachnoid hemorrhage using computed tomographic angiography as the first line of investigation.
abstract: BACKGROUND
  Digital subtraction angiography is recognized as the standard investigation for isolated third nerve palsy thought to be caused by an expanding aneurysm. We reviewed our experience in using computed tomographic angiography (CTA) as the first line investigation for patients presenting with isolated third nerve palsy without subarachnoid hemorrhage.
  
  
  METHODS
  We retrieved the medical records of 34 patients who had presented with isolated third nerve palsy without associated subarachnoid hemorrhage to our institution between January 1998 and July 2001. The clinical history, course and outcome as well as the radiological data was reviewed.
  
  
  RESULTS
  A total of nine structural lesions (26%) were noted as the etiology of the third nerve palsy. All of the five posterior communicating artery aneurysms were picked up by the CTA. Neither the presence nor the absence of painful complete third nerve palsy was of diagnostic value for intracranial aneurysm.
  
  
  CONCLUSIONS
  A good quality CTA is sufficient to detect a compressive aneurysm and may detect other structural lesions. This allows neurosurgeons to plan the management of patients with isolated third nerve palsy. Patients in whom CTA results are inconclusive should be further investigated with catheter angiography.
authors.affiliation: Division of Neurosurgery, Department of Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, PR China.
authors.forename: G K
authors.initials: GK
authors.lastname: Wong
authors.forename: R
authors.initials: R
authors.lastname: Boet
authors.forename: W S
authors.initials: WS
authors.lastname: Poon
authors.forename: S
authors.initials: S
authors.lastname: Yu
authors.forename: J M
authors.initials: JM
authors.lastname: Lam
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015901:Angiography, Digital Subtraction; D002533:Cerebral Angiography; D002648:Child; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D015840:Oculomotor Nerve Diseases / Q000000981:diagnostic imaging* / Q000209:etiology; D012680:Sensitivity and Specificity; D036542:Tomography, Spiral Computed; D016896:Treatment Outcome