Carbon dioxide reactivity and patterns of cerebral infarction in patients with carotid artery occlusion

Summary A total of 106 patients with 112 internal carotid artery occlusions were investigated by cranial computed tomography and transcranial Doppler ultrasonography (CO₂ test), giving a measure of the cerebrovascular reserve capacity. The morphological patterns of the ischaemic lesions were classified into three categories: lacunar, thromboembolic and haemodynamic infarctions. Of 29 patients with an exhausted CO₂ reactivity, 19 showed a haemodynamic type of infarction, whereas of 45 cases with a normal CO₂ reactivity only 2, and of 38 patients with a diminished CO₂ reactivity only 3 had haemodynamically caused infarctions (P<0.001). The correlation between an exhausted CO₂ reactivity and the presence of haemodynamic infarctions could be of value for therapy in patients with carotid artery occlusions.