Article Text

Seasonal variability in spontaneous cervical artery dissection
  1. M Paciaroni1,
  2. D Georgiadis2,
  3. M Arnold3,
  4. J Gandjour2,
  5. B Keseru3,
  6. G Fahrni2,
  7. V Caso2,
  8. R W Baumgartner2
  1. 1Stroke Unit, University Hospital Perugia, Perugia, Italy
  2. 2Department of Neurology, University Hospital Zurich, Zurich, Switzerland
  3. 3Department of Neurology, University Hospital Bern, Bern, Switzerland
  1. Correspondence to:
 Dr Ralf W Baumgartner
 Department of Neurology, University Hospital, Frauenklinikstrasse 26, CH-8091 Zürich, Switzerland; ralf.baumgartner{at}


We examined the seasonal variability of spontaneous cervical artery dissection (sCAD) by analysing prospectively collected data from 352 patients with 380 sCAD (361 symptomatic sCAD; 305 carotid and 75 vertebral artery dissections) admitted to two university hospitals with a catchment area of 2 200 000 inhabitants between 1985 and 2004. Presenting symptoms and signs of the 380 sCAD were ischaemic stroke in 241 (63%), transient ischaemic attack in 40 (11%), retinal ischemia in seven (2%), and non-ischaemic in 73 (19%) cases; 19 (5%) were asymptomatic sCAD. A seasonal pattern, with higher frequency of sCAD in winter (31.3%; 95% confidence interval (CI): 26.5 to 36.4; p = 0.021) compared to spring (25.5%; 95% CI: 21.1 to 30.3), summer (23.5%; 95% CI: 19.3 to 28.3), and autumn (19.7%; 95% CI: 15.7 to 24.1) was observed. Although the cause of seasonality in sCAD is unclear, the winter peaks of infection, hypertension, and aortic dissection suggest common underlying mechanisms.

  • CI, confidence interval
  • DSA, digital subtraction angiography
  • MRA, cerebral magnetic resonance angiography
  • MRI, magnetic resonance imaging
  • sCAD, spontaneous cervical artery dissection
  • sICAD, spontaneous internal carotid artery dissection
  • sVAD, spontaneous vertebral artery dissection
  • cardiovascular disease
  • cervical artery dissection
  • stroke

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  • Competing interests: none declared

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