Carotid artery insufficiency is caused by an abnormal kinked or coiled internal carotid artery in 15-20 per cent of symptomatic patients. Surgical correction should be considered if other causes for the neurological signs are excluded, a pronounced kinked or coiled area is demonstrated and if there is not a severe neurological deficit. As well as eliminating the elongation, surgical correction should include intraluminal inspection of the artery as, in 38-5 per cent of cases, a concomitant arteriosclerotic stenosis requires simultaneous correction.