Abstracts

Rationale: The electroencephalogram (EEG) is one of the most commonly applied method to monitor the possible cerebrovascular insufficiency during endovascular treatment of carotid artery stenosis. EEG may reflect the perfusion status or abnormal electrical activity of the brain. The purpose of this study is to describe the results of EEG alterations relating with the procedure or carotid stenting and the changes of perfusion status in patients with severe carotid stenosis.Methods: Eight patients (6 men; mean age 68 years, 2 women: mean age 70) were enrolled in this study. Seven patients have symptomatic carotid artery stenosis and one patients was asymptomatic carotid artery stenosis. 5 patients were unilateral internal carotid artery (ICA) stenosis and 3 patients were bilateral ICA stenosis. We performed pre-procedural brain single photon emission computed tomography (SPECT) for estimate the brain perfusion. Possible active inflammatory atherosclerosis was evaluated by carotid PET. All patients were treated by percutaneous transluminal balloon angioplasty (PTA) and stent replacement (unilateral:7, bilateral:1). We performed EEG before, during and after the stent insertion in all 8 patients (before insertion: 7, during insertion:6, after insertion:6). Twelve scalp electrodes were applied with collodion according to the International 10-20 system of electrode placement. Results: All patients were successfully treated without severe immediate complications. Visually apparent EEG changes associated with stent replacement appeared in 4 of 6 patients. Before the procedure, five patients showed abnormal EEG findings ipsilateral to the side of carotid stenosis. One patient developed slow waves in the ipsilateral hemisphere just after the ballooning and the small infarction was confirmed by diffusion-weighted MRI after the procedure. After the procedure, four patients revealed improvement of EEG in the side of carotid stenosis and 1 patients showed newly developed EEG abnormality. Conclusions: With the EEG, we may find the changes of perfusion status between pre- and post- stenting procedure. Although it is difficult to evaluate exact extent of perfusion with EEG changes, it may aid to monitor the re-perfusion or detect new lesions such as embolic infarction during carotid stenting in patients with severe carotid stenosis.