OBJECTIVE AND IMPORTANCE: The fenestrated oculomotor nerve associated
with the internal carotid-posterior communicating artery aneurysm is v
ery rare. CLINICAL PRESENTATION: A 48-year-old woman had a history of
subarachnoid hemorrhage caused by a ruptured right middle cerebral art
ery aneurysm, which was wrapped with good postoperative course. Twenty
years later, the patient suffered frontal headache with a mild oculom
otor nerve paresis in the right side. Follow-up neuroimaging studies d
emonstrated a de novo right internal carotid-posterior communicating a
rtery aneurysm. INTERVENTION: The aneurysm was exposed and clipped via
a right pterional route. The fenestrated oculomotor nerve associated
with the aneurysm was confirmed at surgery. CONCLUSION: We speculated
that the fenestration was most likely caused by the growth of the aneu
rysm.