Background: We have recently had many opportunities to operate on patients who presented with no neurologic deficits and were incidentally detected to have unruptured cerebral aneurysms. Therefore, it is very important to know how craniotomy affects the normal brain when making decisions regarding surgery for asymptomatic cerebral diseases.
Methods: Thirty patients with unruptured cerebral aneurysms were evaluated. Aneurysm sites were as follows: internal carotid artery (ICA) (eight cases), anterior communicating artery (ACoA) (seven), middle cerebral artery (MCA) (five), basilar artery-superior cerebellar artery (BA-SCA) (two), and multiple aneurysms (three) [bilateral MCA: (two), ICA + Basilar top: (one)]. These patients underwent neuropsychological examinations [the Mini-Mental State (MMS) test, the "Kana-hiroi" test, and the "Maze" test] and single photon emission computed tomography (SPECT) before and after surgery.
Results: The details of the 17 cases whose Kana-hiroi tests deteriorated 1 month after surgery are as follows: ACoA: seven, MCA: five, ICA: three, BA: two. SPECT showed a decrease in CBF in nine cases (ACoA: six, ICA: two, MCA: one). There was a statistically significant difference (p<0.05) between patients with ACoA aneurysms and ICA aneurysms. Three months after operation, all of the patients with neuropsychological deterioration and four of the six low CBF patients recovered to preoperative levels.
Conclusions: These results indicated that the operation for unruptured cerebral aneurysms is moderately safe and meaningful; such a study should be required to determine when those patients could return to normal life.