The Role of Carotid Artery Stenting and Carotid Endarterectomy in Cognitive Performance

Abstract

Background and Purpose-Change in cognition is being increasingly recognized as an important outcome measure; however, the role of carotid revascularization on this issue remains to be determined. It is still under debate whether carotid artery stenting and carotid endarterectomy have the same influence on neuropsychological functions. Summary of Review-This article systematically reviews recent literature in an attempt to clarify this issue. A total of 32 papers reporting on neurocognition after carotid endarterectomy (nϭ25), carotid artery stenting (nϭ4), or carotid artery stenting versus carotid endarterectomy (nϭ3) were identified. The studies were different for many methodological factors, eg, sample size, type of patients and control group, statistical measure, type of test, timing of assessment, and so on. There was a lack of consensus in defining the improvement or impairment after either carotid artery stenting or carotid endarterectomy. Furthermore, there were nonuneqivocal results regarding the same domain of assessment (memory, visuomotor, attention). Based on available evidence, it is probable that carotid endarterectomy as well as carotid artery stenting do not change neuropsychological function "per se." Conclusions-Assessment of cognition after carotid revascularization is probably influenced by many confounding factors such as learning effect, type of test, type of patients, and control group, which are often minimized in their importance. The role of carotid revascularization is to prevent stroke in patients with severe carotid stenosis as highlighted by previous large randomized trials. Although an effect of carotid revascularization on cognition could be missed as a consequence of underpowered studies included in this review, at this time, no prediction can be done regarding its repercussions on higher intellectual functions. Larger studies appropriately designed and powered to assess cognition after carotid revascularization might change this view. (Stroke. 2008;39:3116-3127.)

Postoperative Changes in Cerebral Metabolites Associated with Cognitive Improvement and Impairment after Carotid Endarterectomy: A 3T Proton MR Spectroscopy Study

“…1,2 While CEA may also improve cognitive function, 3,4 cognitive impairment occurs in 10%-30% of patients following CEA. [5][6][7][8] A recent study reported that 11% of patients undergoing CEA experienced improvement in cognitive function after surgery, while another 11% experienced a decline in cognitive function after surgery.…”

Changes in Cognitive Function After Carotid Endarterectomy in Older Patients: Comparison With Younger Patients

“…A recent study suggested that normalization of cerebral metabolism via improvements in cerebral hemodynamics after CEA may result in cognitive improvement as well as functional recovery of the neurotransmitter system. 5) Other investigators have hypothesized that cognitive impairment after CEA may result from three possible mechanisms 2,[6][7][8][9][11][12][13]18) : cerebral hemispheric hypoperfusion during ICA clamping, intraoperative gaseous and particulate emboli from the surgical site, and postoperative cerebral hyperperfusion. The present study showed no relationship between duration of ICA clamping or new ischemic lesions on postoperative diffusion-weighted imaging and postoperative cognitive change.…”

“…4) Numerous studies have investigated changes in cognitive function following CEA using objective neuropsychological testing and found that, while CEA may improve cognitive function, 9,17) cognitive impairment occurs in 10% to 30% of patients following CEA. 7,12,13,20) However, reports defined no clear criteria for determining significant cognitive improvement or impairment after surgery on neuropsychological test scores, because such postoperative changes may, in part, reflect the``practice effect'' (an improvement in scores when patients are repeatedly tested).…”

Deficits of hand coordination and laterality of carotid endarterectomy

“…Because CEA can be performed on the left or right carotid artery, a number of studies have investigated whether the laterality of CEA plays a role in the kind of cognitive deficits a patient exhibits postoperatively. 7,14,24 Thus far, researchers have focused on the laterality of deficits after CEA in the verbal, 2,7,24 executive, 4,5,9,13,14 and visuospatial domains. 1,7,22 For example, postoperative language changes have been associated primarily with a left CEA.…”

“…7,14,24 Thus far, researchers have focused on the laterality of deficits after CEA in the verbal, 2,7,24 executive, 4,5,9,13,14 and visuospatial domains. 1,7,22 For example, postoperative language changes have been associated primarily with a left CEA. 2,3,15,16,21,24 To the best of our knowledge, no previous studies have associated the laterality of CEA with its influence on subtle postoperative hand deficits of coordination.…”