New brain lesions after carotid revascularization are not associated with cognitive performance

Carotid angioplasty and stenting (CAS) is increasingly being used as a treatment alternative to endarterectomy (CEA) for patients with significant carotid stenosis. However, diffusion-weighted imaging (DWI) has indicated that CAS is associated with a significantly higher burden of microemboli. This study evaluated the potential effect on intellectual functions of new DWI lesions after CEA or CAS.

This prospective study analyzed the neuropsychologic outcomes after revascularization in 24 CAS and 31 CEA patients with severe carotid stenosis compared with a control group of 27 healthy individuals. All patients underwent clinical examinations, magnetic resonance imaging scans, and a neuropsychologic test battery that assessed six major cognitive domains performed immediately before CEA or CAS, ≤ 72 hours after, and at 3 months.

New DWI lesions were detected among 15 of 21 (71%) of the CAS patients immediately after treatment but in only 1 of the 28 CEA patients (4%; P < .01). As a group, patients with new DWI lesions showed a decline in their performance in the cognitive domains, attention, and visuoconstructive functions within 72 hours of carotid revascularization. Individually, however, in none of the cognitive domains did the decreases reach a clinically relevant threshold of z < -1.5. Moreover, the cognitive performance was not significantly different between patients with and without new DWI lesions 3 months after treatment. The cognitive performance was similar between CEA and CAS patients at all points.

The findings support the assumption that new brain lesions, as detected with DWI after CAS or CEA, do not affect cognitive performance in a manner that is long-lasting or clinically relevant. Despite the higher embolic load detected by DWI, CAS is not associated with a greater cognitive decline than CEA.