Comparison of domain-specific cognitive function after carotid endarterectomy and stenting

Background: Observational data indicate that carotid artery stenting (CAS) is associated with higher incidence of subclinical cerebral microemboli than carotid endarterectomy (CEA). We hypothesized that CEA would be associated with superior performance on detailed domain-specific cognitive testing compared with CAS. Methods: Patients with >80% asymptomatic carotid artery stenosis were randomized to CEA or CAS with side of stenosis balanced across condition. A robust battery of tests was used to assess the cognitive domains of attention, memory, mood, visual-spatial skills, motor ability, processing speed, and executive functioning <= 10 days preoperatively and postoperatively at 6 weeks and 6 months. Tests were administered using standardized conditions and were scored by individuals blinded to treatment allocation. Results: Baseline cognitive performance was similar between CAS (n=29) and CEA (n=31) groups (P > .05). Relative to baseline, verbal and visual memory and attention functions substantially improved in the CAS and CEA groups at 6 months (multiple cognitive tests achieved statistical significance). Compared with CEA, cognitive processing speed (Stroop Color test: 9.0 vs 7.3, P = .04; and Stroop Word test: 9.0 vs 7.4, P = .05) was superior in the CAS group at 6 weeks. Executive functioning (phonemic verbal fluency: 10.6 vs 8.4, P = .043) and motor function (Grooved Pegboard of nondominant extremity: 45.7 vs 38.9, P = .022) were also superior in the CAS group at 6 months. Tests of attention, memory, and visual-spatial skills were similar between CAS and CEA patients at 6 weeks and 6 months. Conclusions: Carotid revascularization improves memory and attention within the first 6 postoperative months. Compared with CEA, CAS produces improvements in cognitive processing speed, executive functioning, and motor function.