Is there any seasonal influence in spontaneous bleeding of intracranial aneurysm and and/or AVM in Istanbul?
PRINCIPLES: Despite many reports investigating the relationship of subarachnoid haemorrhage and seasonal variation in different parts of the world, there is no clear correlation. As far as we know this subject has not been reported from Istanbul yet. The purpose of this study is to determine if there is any correlation between season and spontaneous subarachnoid haemorrhage (SAH) caused by intracranial aneurysms and/or arteriovenous malformations (AVM) in Istanbul. METHODS: Data were collected retrospectively from the medical reports of patients having intracranial haemorrhage due to aneurysm and/or arteriovenous malformation. The data were analysed with univariate and chi-square tests for all haemorrhages, for haemorrhages of aneurysms and arteriovenous malformations separately per month and per season respectively for all the patients together and according to gender separately. The ANOVA test was used for testing the monthly distribution of SAH cases with regard to age. RESULTS: The