A blind controlled trial of dextran 40 in the treatment of ischaemic stroke.

A blind controlled trial of dextran 40 in ischaemic stroke is reported. In the treated group mortality in the acute stage in patients with severe strokes was significantly reduced but survivors were severely disabled and six months later no significant benefit could be detected. In less severe strokes no effect of treatment was found. It is concluded that the action of dextran 40 in reducing acute mortality probably lay in preventing or reversing cerebral swelling but no evidence of the expected action in reducing the area of infarction following improved blood flow was found. The importance of extending assessment beyond the two weeks customary in therapeutic trials in stroke is emphasized.