Effects of Carotid Endarterectomy on Cerebral Reperfusion and Cognitive Function in Patients with High Grade Carotid Stenosis: A Perfusion Weighted Magnetic Resonance Imaging Study

Abstract

To investigate the influence of carotid endarterectomy (CEA) on cerebral perfusion and cognitive function in patients with internal carotid artery stenosis (ICA). Patients were prospectively enrolled in this study. Shunted patients were excluded. Cerebral perfusion was measured by magnetic resonance (MR) perfusion weighted imaging (PWI) and diffusion weighted imaging (DWI) in 46 patients with >65% ICA (31 males, 64.5 ± 6.7 years) 1 week before and 6 weeks after CEA. Cognitive function was assessed using the Mini Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA) 1 week before and 6 weeks after CEA. After CEA, perfusion parameters from PWI decreased, including mean transit time (MTT) (21.07 ± 7.36 vs. 14.27 ± 6.22, p < .0001), time to peak (TTP) (28.69 ± 8.54 vs. 23.45 ± 4.25, p = .001), arrive time (T0) (19.89 ± 7.32 vs. 15.20 ± 3.51, p = .001), and relative cerebral blood volume (rCBV) (11.48 ± 3.50 vs. 7.53 ± 3.17, p < .0001). A significant improvement was observed in MoCA (20.48 ± 1.70 vs. 22.04 ± 1.48, p = .001). Spearman's rank correlation analysis between TTP and MoCA scores demonstrated a linear relationship with an excellent correlation coefficient (R = -.893, p < .001). Linear regression indicated that diabetes was a risk factor for cognitive improvement in patients with ICA (p = .014). Further analysis showed that patients with DM performed worse in MoCA after the procedure (with-DM 21.15 ± 1.28 vs. non-DM 22.4 ± 1.46, p = .010) while the baselines were similar (non-DM: 20.3 ± 1.8 vs. with-DM: 20.9 ± 1.4, p = .362). CEA could improve the cerebral perfusion and the cognitive function in un-shunted ICA patients. Cerebral reperfusion was an important factor for cognitive improvement. Diabetes had a negative effect on cognitive improvement after CEA.