title: Small unruptured cerebral aneurysms presenting with oculomotor nerve palsy.
abstract: OBJECTIVE
  Symptomatic unruptured aneurysms have been considered at relatively high risk for future rupture, and the majority of aneurysms that cause symptoms of mass effect are large. Unruptured aneurysms smaller than 1 cm in diameter sometimes cause neurological symptoms, but their clinical aspects remain obscure. In this article, we review our experience with small unruptured aneurysms presenting with oculomotor nerve palsy.
  
  
  METHODS
  Sixteen patients with unruptured aneurysms smaller than 1 cm presenting with oculomotor nerve palsy were included in this study. The patients' clinical profiles were reviewed, and factors affecting the recovery of oculomotor function were determined.
  
  
  RESULTS
  The mean size of the aneurysms was 5.8 +/- 1.4 mm. Eleven patients (68.8%) had preceding retrobulbar pain. Fifteen patients underwent successful microsurgical clipping or intravascular embolization, but one patient died of aneurysm rupture before surgery. Seven patients (43.8%) had a complete recovery of oculomotor function, six (37.5%) had an incomplete recovery, and two (12.5%) remained unchanged after treatment. The mean interval between the onset of oculomotor nerve palsy and treatment was 4.7 +/- 3.3 days in patients with complete recovery, 24.2 +/- 15.5 days in patients with incomplete recovery, and 41.0 +/- 12.7 days in unchanged patients. Early surgery resulted in more complete recovery of neural function (P < 0.01).
  
  
  CONCLUSIONS
  Unruptured aneurysms smaller than 1 cm can cause neurological symptoms of mass effect. We recommend timely surgery, preferably within 5 days, to avoid not only aneurysm rupture but also functional disability even in patients with unruptured aneurysms smaller than 1 cm.
authors.affiliation: Department of Neurosurgery, Institute of Clinical Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan. kyanaka@md.tsukuba.ac.jp
authors.forename: Kiyoyuki
authors.initials: K
authors.lastname: Yanaka
authors.forename: Yuji
authors.initials: Y
authors.lastname: Matsumaru
authors.forename: Ryota
authors.initials: R
authors.lastname: Mashiko
authors.forename: Akio
authors.initials: A
authors.lastname: Hyodo
authors.forename: Koichi
authors.initials: K
authors.lastname: Sugimoto
authors.forename: Tadao
authors.initials: T
authors.lastname: Nose
mesh_terms: D000328:Adult; D000368:Aged; D017542:Aneurysm, Ruptured / Q000175:diagnosis / Q000517:prevention & control*; D002533:Cerebral Angiography; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications* / Q000175:diagnosis / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015840:Oculomotor Nerve Diseases / Q000175:diagnosis / Q000209:etiology* / Q000601:surgery*; D017063:Outcome Assessment, Health Care; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013997:Time Factors; D014057:Tomography, X-Ray Computed