Heterogeneity of cerebral perfusion one week after haemorrhage is an independent predictor of clinical outcome in patients with aneurysmal subarachnoid haemorrhage

¹ Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital, Finland
² Department of Neurosurgery, Kuopio University Hospital, Finland
³ Department of Clinical Radiology, Kuopio University Hospital, Finland
⁴ Department of Neurology, Kuopio University Hospital, Finland

^* To whom correspondence should be addressed. E-mail: esko.vanninen{at}kuh.fi.

Accepted 23 February 2008

	Abstract

Background and purpose: Aneurysmal subarachnoid haemorrhage (aSAH) can be associated with acute global and regional decrease in cerebral perfusion. Furthermore, cerebral vasospasm may lead to development of delayed ischaemic deficits. The aim of the study was to find out whether cerebral perfusion heterogeneity, an indicator of cerebral microvascular function and autoregulation, measured by single-photon emission tomography (SPET) is able to predict the long-term clinical outcome of aSAH.

Methods: The perfusion SPET data of 55 patients with aSAH were analysed by dividing the brain into 384 regions of interest. Spatial perfusion heterogeneity was assessed by calculating the relative dispersions (RD, coefficient of variation) from the SPETs performed before treatment (RD1) and one week after early surgical or endovascular treatment of the ruptured aneurysm (RD2). Both RDs were compared to the clinical outcome (Glasgow Outcome Scale, GOS), neuropsychological test scores and late ischaemic findings in MRI one year after SAH.

Results: High RD2 (OR 1.96; 95% CI 1.18-3.26; p = 0.009) and poor clinical condition (Hunt and Hess grade) on admission (OR 6.60; 95% CI 1.78-24.52; p = 0.005) proved to be independent predictors of poor or moderate clinical outcome (GOS 1-4). RD2 was higher in patients with ischaemic findings in 12-month MRI than in those without ischaemic findings (p = 0.008). RD2 also correlated with neuropsychological outcome one year after aSAH.

Conclusions: Perfusion heterogeneity is an independent predictor of the clinical outcome of aSAH and may thus be a valuable measure in the assessment of the disease.