Association of the recovery of objective abnormal cerebral perfusion with neurocognitive improvement after carotid revascularization

Objectives This study sought to report the effect of carotid artery stenting (CS) on neurocognitive function (NCF) in patients with severe carotid artery occlusive disease, depending on baseline brain perfusion status. Background The effect of CS on NCF has been controversial. Methods We prospectively enrolled 61 patients with carotid artery disease (22 with occlusion, 39 with severe stenosis) in whom CS was attempted. Computed tomography perfusion and NCF assessments including Mini-Mental State Examination (MMSE), Alzheimer Disease Assessment Scale-Cognitive subscale (ADAS-Cog), verbal fluency, and Color Trails Test Parts 1 and 2 were applied before and 3 months after intervention. Results Successful recanalization was achieved in 14 of 22 occlusion patients (64%) and in all 39 severe stenosis patients. Two cases were excluded due to procedural cerebral complications. The patients were divided into 3 groups: group 1 (n = 8) consisted of patients with abnormal baseline ipsilateral cerebral perfusion in whom CS failed; group 2 (n = 33) consisted of patients with abnormal baseline ipsilateral cerebral perfusion in whom CS was successful; and group 3 (n = 19) consisted of patients without abnormal baseline ipsilateral cerebral perfusion in whom CS was successful. The demographics and baseline NCF were similar among groups. Only in group 2 was there significant improvement in ADAS-Cog (pre-procedure median [interquartile range]: 6 [4 to 9] vs. post-procedure: 5 [3 to 7], p = 0.002), MMSE (pre-procedure: 27 [25 to 28] vs. post-procedure: 28 [25 to 29], p = 0.004) and Color Trails Test Part 1 (pre-procedure: 100 [78.5 to 136.5] s vs. post-procedure: 97 [60 to 128.5] s, p = 0.003) after CS. Significant difference in changes from baseline was observed only in the Color Trails Test Part 1 among groups (group 1 vs. 2 vs. 3: 1.5 [-14 to 11.5] vs. -12.5 [-36.5 to 0.5] vs. -0.5 [-11 to 27], p = 0.0159). Significant correlation between the change of ipsilateral brain perfusion and MMSE (r = -0.33, p = 0.01) was also identified. Conclusions Successful CS for severe carotid stenosis/occlusion improves NCF, but only in patients with objective baseline abnormal cerebral perfusion.