gms | German Medical Science

64th Annual Meeting of the German Society of Neurosurgery (DGNC)

German Society of Neurosurgery (DGNC)

26 - 29 May 2013, Düsseldorf

Meteorological influences on the incidence of aneurysmal subarachnoid hemorrhage – A single center study of 513 patients

Meeting Abstract

  • Marian Christoph Neidert - University Hospital Zurich, Department of Neurosurgery, Zurich, Switzerland
  • Michael Sprenger - Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
  • Heini Wernli - Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
  • Jan-Karl Burkhardt - University Hospital Zurich, Department of Neurosurgery, Zurich, Switzerland
  • Oliver Bozinov - University Hospital Zurich, Department of Neurosurgery, Zurich, Switzerland
  • Niklaus Krayenbühl - University Hospital Zurich, Department of Neurosurgery, Zurich, Switzerland
  • Luca Regli - University Hospital Zurich, Department of Neurosurgery, Zurich, Switzerland
  • Christoph Michael Woernle - University Hospital Zurich, Department of Neurosurgery, Zurich, Switzerland

Deutsche Gesellschaft für Neurochirurgie. 64. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC). Düsseldorf, 26.-29.05.2013. Düsseldorf: German Medical Science GMS Publishing House; 2013. DocMI.11.01

doi: 10.3205/13dgnc366, urn:nbn:de:0183-13dgnc3668

Published: May 21, 2013

© 2013 Neidert et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en). You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.


Outline

Text

Objective: There is ongoing debate on seasonal and meteorological influences on the incidence of spontaneous subarachnoid hemorrhage (SAH) due to ruptured intracranial aneurysms. To assess the influence of weather on SAH, we analyzed hourly meteorological parameters from three measurement sites around Zurich run by the Swiss Meteorological Service in a group of 513 patients suffering aneurysmal SAH in the Zurich region.

Method: We retrospectively analyzed 513 SAH admissions between 2003 and 2012; aneurysmal rupture occurred within the Zurich region. The parameters considered are: 2-m temperature, surface pressure, 2-m relative humidity, sunshine hours, precipitation and 2-m wind gusts. For all meteorological parameters we consider three complementary statistical measures: i) the deviation from the 9-year monthly mean; ii) the change relative to the parameter's value two days before the SAH occurrence; and iii) the time evolution from 5 days before to 5 days after the SAH occurrence. The statistical significance of the results is determined by a re-sampling technique, i.e., we artificially create 1000 samples of 513 days, where the dates are randomly distributed except for the seasonal cycle which is in accordance with the observed 513 SAH events. For all 1000 random samples the three statistical analyses are repeated and their outcome is then compared to the sample for the SAH days.

Results: No statistically significant signal could be found for any of the meteorological parameters, i.e., the distributions of deviations relative to the climatology and of the changes during the two days prior to SAH events fully agree with the distributions for the randomly chosen days. The analysis was repeated separately for winter and summer to exclude compensating effects between the seasons.

Conclusions: In summary, the sophisticated statistical analysis negates a clearly identifiable meteorological influence for the 513 SAH events considered, at least at the daily time scale considered in this study. Impacts of within-day and spatially confined meteorological fluctuations are still possible, but are beyond the scope of this study. Such an analysis would be much more complex to perform as it required very detailed information about the time and location of the SAH occurrences.