Neuropsychometric Changes in Patients After Carotid Endarterectomy

Abstract

Background and Purpose-One hundred twelve patients undergoing elective carotid endarterectomy for symptomatic and asymptomatic carotid artery stenosis were enrolled in a prospective study to evaluate the incidence of change in postoperative cerebral function. Methods-Patients were evaluated preoperatively and postoperatively before hospital discharge and at follow-up 1 and 5 months later with a battery of neuropsychometric tests. The results were analyzed by both event-rate and group-rate analyses. For event-rate analysis, change was defined as either a decline or improvement in postoperative neuropsychometric performance by 25% or more compared with a preoperative baseline. Results-Approximately 80% of patients showed decline in one or more test scores, and 60% had one or more improved test scores at the first follow-up examination. The percentage of declined test scores decreased and the percentage of improved test scores increased with subsequent follow-up examinations. Group-rate analysis was similar for group performance on individual tests. However, a decline in performance was seen most commonly on verbal memory tests, and improved performance was seen most commonly on executive and motor tests. Conclusions-Neuropsychometric evaluation of patients undergoing carotid endarterectomy for significant carotid artery stenosis demonstrates both declines and improvements in neuropsychometric performance. The test changes that showed decreased performance may be associated with ischemia from global hypoperfusion or embolic phenomena, and the improvement seen may be related to increased cerebral blood flow from removal of stenosis. (Stroke. 1998;29:1110-1115.)

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). 12,17) In contrast, physicians and/or patients' families often report subjective postoperative improvements or impairments in cognition for patients undergoing CEA; indeed, patients º76 years old who underwent CEA experienced subjective improvement in 11% and impairment of cognition in 11% of cases after surgery.…”

“…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). 12,17) In contrast, physicians and/or patients' families often report subjective postoperative improvements or impairments in cognition for patients undergoing CEA; indeed, patients º76 years old who underwent CEA experienced subjective improvement in 11% and impairment of cognition in 11% of cases after surgery. 22) Further, neuropsychological testing can detect subjective improvement and impairment in cognition after surgery if the optimal cut-off points for changes of the test scores are defined.…”

The impact of carotid revascularization on cognitive function

“…1,26,38,[40][41][42][43][44] Carotid endarterectomy is generally associated with longer periods of ipsilateral carotid flow privation (mean duration of 337 seconds) than CAS (mean duration of 26 seconds; p<0.001). 43 A study with patients submitted to heart surgery demonstrated that hypoperfusion during the procedure was related to attention deficit.…”

“…23,26,44 The most widely used strategies intended to avoid hypoperfusion during CEA are either a selective shunt (guided by cerebral monitoring using continuous electroencephalogram, TCD or neurological examination) or a universal shunt. 26,41,[44][45][46] More recently, cerebral oximetry, bispectral index and evoked potentials are also being used for cerebral monitoring during surgery at some centers. 24,47,48 Additionally, another event that can occur in relation to both types of revascularization procedure is systemic hypotension, defined as a drop in systemic systolic pressure of >30 mmHg, compared with baseline, 26,45 which is more frequent with CAS (more than 68% of patients), [49][50][51][52] and is associated with elevated levels of biochemical markers (S100B) of glial injury.…”