The effect of heliox treatment in a rat model of focal transient cerebral ischemia

► Helium/oxygen protects the brain against acute focal ischemia stroke. ► 70%/30% helium/oxygen decreased infarct size and improved neurological outcome. ► Delayed treatment for 30-60 min resulted in a trend towards beneficial effects. ► 40%/30%/30% nitrogen/helium/oxygen was less effective than 70%/30% helium/oxygen.