Project Overview

Background

Stroke is the second cause of death world-wide and the second cause of lost disability-adjusted life years in high-income countries. Because stroke incidence rises exponentially with age, the social and economic burden of stroke will rise further with the ageing of the population. The large majority of strokes (about 80%) are caused by arterial or arteriolar occlusion. Treatment options for these ischaemic strokes are extremely limited.

Systematic review of animal studies modelling ischaemic stroke suggests that cooling is the most promising intervention identified to date. In these animal studies, cooling to 35˚C reduced infarct size by about one third, and cooling to 34°C by around 45%. Moreover, several prospective observational studies in stroke have shown an association between raised body temperature and poor outcome, and between low body temperature and good outcome.

Finally, cooling improves outcome in patients with hypoxic-ischaemic brain injury after cardiac arrest. Hypothermia is therefore the most promising treatment for patients with acute ischaemic stroke. Cooling awake patients with ischaemic stroke to 35°C has been shown feasible and safe, but whether this improves functional outcome has not yet been tested in an adequately-sized randomised clinical trial.

Aim

To determine whether systemic cooling to a target temperature of 34 to 35°C, started within 6 hours of symptom onset and maintained for 24 hours, improves functional outcome at 3 months in patients with acute ischaemic stroke.