Cognition and Hemodynamics after Carotid Endarterectomy for Asymptomatic Stenosis

Aim: To test a brain haemodynamics examination protocol using magnetic resonance imaging and to investigate the differences in cognitive performance with a neuropsychology test battery RBANS (Repeatable Battery for the Assessment of Neuropsychological Status) on a cohort of patients with an asymptomatic carotid stenosis undergoing carotid endarterectomy. Methods: Standard carotid endarterectomy in asymptomatic carotid stenosis under general intravenous anaestehesia with selective use of a shunt. Flow measurement in major vessels of the Willis circle using magnetic resonance angiography with phase contrast before and three months after the operation and concurrently with RBANS psychological examination testing battery. Results: Significant cognitive performance improvement in neuropsychological test battery total score and in short-term memory (p = 0.04) and speech (p = 0.01) indexes was seen in five women and 12 men undergoing uncomplicated carotid endarterectomy. Subsequent correlations of local haemodynamic change and cognitive performance change in 12 patients were significant for the anterior cerebral artery and immediate memory index (p = 0.01), and for the medial cerebral artery and speech indeces (p = 0.02) and visuospatial orientation (p = 0.02). Conclusion: In a pilot study, a flow (ml/min) examination protocol of all major Willis circle arteries was tested and haemodynamic changes before the operation and in three months follow-up after carotid endarterectomy were compared on a small group of patients with radiologically and clinically asymptomatic carotid stenosis for the first time in Czech literature. Improvement in cognitive performance was demonstrated and an association with anterior or medial cerebral artery flow values was identified in individual RBANS tests. A larger study with a longer follow-up is feasible.