Prevalence of unruptured intracranial aneurysms among first-degree relatives of Thai patients who had aneurysmal subarachnoid hemorrhage

BACKGROUND: The prevalence of familial unruptured intracranial aneurysm (UIA) in Thai population was unknown. METHODS: Our study population comprised first-degree relatives of patients who were diagnosed with aneurysmal subarachnoid hemorrhage (aSAH) in two cerebrovascular neurosurgical centers from January 2018 to December 2018. The volunteers underwent three-dimensional time-of-flight magnetic resonance angiography for screening intracranial aneurysms (IA). Those who were reported positive or suspected of IA then underwent computed tomography angiography for confirmation. RESULTS: We identified 12 patients who had 12 unruptured IAs (UIAs) from among 93 first-degree relatives. The prevalence of UIA among our study population was 12.9%. An estimated prevalence of UIA among Thai population was 9.05% (95% confidence interval [CI] 7.32–10.78). Of the 93 relatives, 84 had only one first-degree relative who suffered aSAH. Siblings posed a higher risk for UIA than offspring (16% vs. 9.5%), but the difference was not statistically significant (odds ratio 1.810, 95% CI 0.50–6.50, P = 0.274). The most common aneurysm location was the anterior cerebral artery territory (50%). CONCLUSION: The prevalence of familial UIA in a Thai population was relatively high. There was no significant between-group difference in the occurrence of UIA between the siblings and offspring of the aSAH patients.