Limb-shaking is a specific clinical feature of transient ischaemic attacks that has been associated with a high-grade stenosis or occlusion of the internal carotid artery. The aim of this study was to describe the clinical characteristics of limb-shaking in patients with internal carotid artery occlusion and to investigate whether patients with limb-shaking have a worse haemodynamic state of the brain than patients with internal carotid artery occlusion without limb-shaking. We included 34 patients (mean age 62 + or - 7 years, 82% male) with limb-shaking associated with internal carotid artery occlusion and 68 sex- and age-matched controls with cerebral transient ischaemic attack or minor disabling ischaemic stroke associated with internal carotid artery occlusion, but without limb-shaking. We investigated clinical characteristics, collateral pathways on contrast angiograms and carbon dioxide-reactivity measured by transcranial Doppler. The results showed that limb-shaking usually lasted less than 5 min and was often accompanied by paresis of the involved limb. Compared with controls, patients with limb-shaking more frequently had symptoms precipitated by rising or exercise (odds ratio 14.2, 95% confidence interval 4.2-47.9), more frequently had recurrent ischaemic deficits after documented internal carotid artery occlusion (but before inclusion in the study) (odds ratio 8.2, 95% confidence interval 2.3-29.3), more often had leptomeningeal collaterals (odds ratio 6.8, 95% confidence interval 2.0-22.7), and tended to have a lower carbon dioxide-reactivity (mean 5% + or - 16 versus 12% + or - 17; odds ratio 0.97 per 1% increase in carbon dioxide-reactivity, 95% confidence interval 0.94-1.00). In conclusion, limb-shaking transient ischaemic attacks in patients with internal carotid artery occlusion can be recognized by their short duration, are often accompanied by paresis and precipitated by rising or exercise and are indicative of an impaired haemodynamic state of the brain.