Incidental cerebral aneurysms in acute stroke patients: comparison of asymptomatic healthy controls

Cerebral aneurysms (CA) are incidentally detected by magnetic resonance angiography (MRA) in acute stroke patients or asymptomatic volunteers. We investigated whether incidental CA influences stroke subtypes and clinical outcome of patients with acute brain infarction (BI) and hemorrhage (BH). Moreover, frequency and neuroradiological profile of incidental CA were compared between acute stroke patients and asymptomatic healthy controls. We included consecutive BI and BH patients who underwent magnetic resonance imaging and MRA within 7 days from clinical onset. CA diagnosis was performed by 3-dimensional time-of-flight MRA. Demographics, risk factors, stroke subtypes, and modified Rankin scale (mRS) at 3 months after stroke were assessed. Incidental CA was detected in 18 (3.7%) of 481 stroke patients, 13 (3.5%) of 374 BI patients, 5 (4.7%) of 107 BH patients, and 146 (2.0%) of 7345 controls. Multivariate analysis showed no significant differences in CA frequency between BI, BH, and control groups. Female sex was associated independently with incidental CA in the stroke (P<0.01), BI (P<0.05), BH (P<0.05), and healthy control groups (P<0.01). No statistical differences in CA size and location between the 4 groups were found. BI subtypes and BH sites were not correlated with incidental CA. CA rupture or subarachnoid hemorrhage did not occur until 3 months after stroke. The 3-month mRS score did not differ between stroke patients with and without CA. Prevalence of incidental CA did not differ statistically among stroke, BI, BH patients and healthy asymptomatic subjects. The 3-month mRS score was not affected by incidental CA. Female sex was only an independent factor for incidental CA. Thus, we should pay more attention to incidental CA in female BI patients treated with tissue plasminogen activator.