gms | German Medical Science

57th Annual Meeting of the German Society of Neurosurgery
Joint Meeting with the Japanese Neurosurgical Society

German Society of Neurosurgery (DGNC)

11 - 14 May, Essen

Are there seasonal and climatic influences on the incidence of subarachnoid hemorrhage? An analysis from the Düsseldorf metropolitan area

Bestehen jahreszeitliche oder klimatische Faktoren, die die Inzidenz von subarachnoidalen Blutungen beeinflussen? Eine Analyse aus dem Großraum Düsseldorf

Meeting Abstract

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  • corresponding author K. Beseoglu - Neurochirurgische Klinik, Universitätsklinik Düsseldorf
  • H. Steiger - Neurochirurgische Klinik, Universitätsklinik Düsseldorf

Deutsche Gesellschaft für Neurochirurgie. Japanische Gesellschaft für Neurochirurgie. 57. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), Joint Meeting mit der Japanischen Gesellschaft für Neurochirurgie. Essen, 11.-14.05.2006. Düsseldorf, Köln: German Medical Science; 2006. DocP 09.132

The electronic version of this article is the complete one and can be found online at:

Published: May 8, 2006

© 2006 Beseoglu et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Objective: A number of publications suggest seasonal influences on the incidence of subarachnoid hemorrhage (SAH). Most series agree on a peak incidence during springtime. Meteorological influences are the obvious explanation for seasonal variations and also for the apparent short-period clustering of the incidence of SAH that is observed in most mid-size neurovascular services.

Methods: We retrospectively examined 183 patients treated at our department from January 2003 to June 2005 for SAH that had occurred within the Düsseldorf metropolitan area. We correlated the date of SAH with the meteorological key parameters (METARS) from Düsseldorf International Airport and the trends during the week preceding the event.

Results: The incidence of SAH was only during the first month following the change-over to daylight saving time consistently elevated, that is mainly in April. The incidence during this period was 10.3 events compared to a monthly average of 6.1 (P<0.05). Average barometric pressure on the day of hemorrhage, and 1, 3, 5 and 7 days before was 1016 mbar each. Mean daily temperature on the day of hemorrhage, and 1, 3, 5 and 7 days before was 11.0, 10.9, 10.5, 11.0, and 11.4 degrees Celsius. Precipitation (rain, thundershowers, snow) was noticed on the day of hemorrhage and 1, 3, 5 and 7 days before, in 45%, 47%, 45%, 47% and 42% respectively. None of the average key parameters of the day of SAH differed from the annual average nor existed any trends during the days preceding hemorrhage.

Conclusions: Apparent clustering of the occurrence of SAH cannot be related to short-term meteorological trends in the Düsseldorf metropolitan area. The observed relative peak during the month of April is not due to specific meteorological trends. The April peak can be explained by the increasing activity of the population during longer daytime. This effect might be accentuated by the change-over to daylight saving time.