Asymptomatic unruptured intracranial aneurysms in the older people

Purpose: Unruptured intracranial aneurysm commonly occurs in the older people. Because the rupture risk increases with age, the factors associated with aneurysms might be different according to age. We aimed to evaluate unruptured intracranial aneurysm characteristics in healthy, symptom-free older patients. Methods: Patients who visited the health examination center of two regional university hospitals and underwent computed tomography angiography between March 2001 and March 2017 were included. The putative aneurysm risk factors were identified; the aneurysm size and shape were determined by CT angiography, and measuring the ASPECT and dome/neck ratios. All images were interpreted independently by a neurosurgeon and a neurologist for improving size measurement accuracy. Results: The unruptured intracranial aneurysm prevalence was 2.23% and 2.75% in the patients aged ≤ 60 and > 60 years, respectively. Among the younger group, female sex [odds ratio (OR), 1.85; P = 0.002], age (OR, 1.05; P < 0.001), hypertension (OR, 1.88; P < 0.001), coronary artery disease (OR, 0.26; P < 0.001), smoking (OR, 2.04; P < 0.001), and stroke family history (OR, 1.36; P = 0.047) were independently associated with aneurysm; anterior communicating artery aneurysms were the largest. Among the older group, female sex (OR, 1.76; P = 0.005), hypertension (OR, 2.54; P < 0.001), coronary artery disease (OR, 0.27; P < 0.001), and stroke family history (OR, 1.94; P = 0.003) were independently associated with aneurysm; internal carotid artery aneurysms were the largest. Conclusions: The factors related to unruptured intracranial aneurysm formation varied by age, and coronary artery disease protected against aneurysm formation regardless of age. The factors affecting unruptured intracranial aneurysm formation are different according to age and aneurysm location.