The Role of Meteorological Factors in Cerebral Anterior versus Posterior Circulation Aneurysm Rupture

Сerebral arterial aneurysm (AA) ruptures may be associated with climatic and meteorological factors (e.g., temperature, atmospheric pressure [AP], and seasonality), alongside well-established risk factors such as comorbidities and socioeconomic status. Previous studies have shown mixed results concerning the influence of weather on the prevalence of aneurysmal subarachnoid hemorrhage. There is no consensus on the effect of climate on the risk of AA rupture depending on their localization in anterior and posterior circulation AA.

This retrospective, single-center cohort study aimed to investigate the associations between meteorological factors and the anterior versus posterior circulation cerebral AA rupture. It is based on the analysis of 344 medical records of patients treated for aneurysmal subarachnoid hemorrhage in Odesa, Ukraine, from 2000 to 2023. Patients were divided into 2 groups based on the location of the AA. Meteorological data were collected from 4 local weather stations.

Temperature, AP, and day length showed multidirectional effects on the likelihood of complex hemorrhage types. Colder temperatures and higher AP were associated with reduced risk, particularly for hemorrhages involving a parenchymal component and epidural hematomas. The effect of hypertension on anterior and posterior circulation AA rupture could not be determined due to limitations in group sizes and sample size.

Our findings highlight the possible impact of both meteorological and socio-medical factors of AA ruptures. Posterior circulation AA appeared to rupture more often in summer, while anterior circulation AA, in winter and fall, with hypertension, AP, and employment emerging as significant contributors.