Small unruptured cerebral aneurysms presenting with oculomotor nerve palsy

Neurosurgery. 2003 Mar;52(3):553-7; discussion 556-7. doi: 10.1227/01.neu.0000047816.02757.39.


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).

Conclusion: 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.

MeSH terms

  • Adult
  • Aged
  • Aneurysm, Ruptured / diagnosis
  • Aneurysm, Ruptured / prevention & control*
  • Cerebral Angiography
  • Female
  • Humans
  • Intracranial Aneurysm / complications*
  • Intracranial Aneurysm / diagnosis
  • Intracranial Aneurysm / surgery*
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Oculomotor Nerve Diseases / diagnosis
  • Oculomotor Nerve Diseases / etiology*
  • Oculomotor Nerve Diseases / surgery*
  • Outcome Assessment, Health Care
  • Retrospective Studies
  • Severity of Illness Index
  • Time Factors
  • Tomography, X-Ray Computed