Effects of carotid endarterectomy on cerebral blood flow and neuropsychological test performance in patients with high-grade carotid stenosis
Introduction
Cognitive function has been reported to be impaired in patients with occlusive carotid artery disease [1]. However, there is still little data available concerning the changes in neuropsychological functions following carotid endarterectomy (CEA). The effects of CEA on cognitive function reported have varied from study to study [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12], [13], [14], [15], [16], [17]. This heterogeneity might be caused by various factors including individual variation, complications due to multiple perioperative variables and the choice of neuropsychological tests. The timing of the assessment, practice and strategic responses and the type of analyses used may also affect the conclusion. As a result, the effect of CEA on neuropsychological functions remains controversial. Moreover, none of the previous studies included measurement of the cerebrovascular reserve.
Intracranial carotid lesions have been reported to be more common than extracranial ones in Japanese, while it is the opposite for Caucasians [18], [19]. Although we demonstrated that extracranial atherosclerotic carotid lesions are also increasing in Japanese [20], no data is yet available concerning cognitive impairment in Japanese patients with high-grade carotid stenosis. In the present study, we examined changes in the cerebral blood flow (CBF) and neuropsychological functions following CEA in Japanese patients with unilateral carotid stenosis to elucidate the effect of CEA on neuropsychological function.
Section snippets
Patients
The subjects consisted of 23 patients who underwent CEA and 17 age-matched controls. The patients were selected from 42 consecutive patients who were admitted to our hospital and underwent CEA between 1999 and 2001. Patients having more than 60% contralateral carotid stenosis, a physical disability (Rankin disability scale>1) or a history of neuropsychological impairment due to ipsilateral cerebral infarction, were excluded from the analysis. A neurologist (Y.O.) selected 17 controls of similar
Demographic and clinical features of the patients
The mean ages of the patients and controls were 68.0±6.6 and 66.6±6.8 years, respectively. The average degree of stenosis was 83.2±11.5%. Table 1 summarizes the clinical characteristics of the patients and controls. No significant difference in age and sex was detected between the groups. The rate of concomitant risk factors including smoking, hypertension, hyperlipidemia and diabetes mellitus was similar between patients and controls.
CBF and carotid stenosis
The resting state CBF was decreased in 15 patients (65%). Of
Cerebral hemodynamics in carotid stenosis
Hemodynamic failure is defined as a fall in the cerebral perfusion pressure below the lower threshold of cerebral autoregulation. Stenosis of the carotid artery is involved in distal hemodynamic failure by lowering the cerebral perfusion pressure. The blood flow may be affected by various factors, including the cross-sectional area, length of the stenosis, flow velocity and blood viscosity. The most significant factor in carotid stenosis is the cross-sectional area. A previous report showed
Acknowledgements
The authors thank Drs. Fukunaga and Hashida for their skillful assistance in performing the neuropsychological tests. We are also grateful to Drs.Yasumori, Arakawa, Katsuta and Yoshinaga for their useful suggestions. This study was supported by Research Grants for Cardiovascular Diseases (12A-2 and 12C-10) from the Ministry of Health and Welfare of Japan.
References (33)
- et al.
The effect of small infarcts and carotid endarterectomy on postoperative psychologic test performance
J. Surg. Res.
(1980) - et al.
Uncomplicated carotid endarterectomy is not associated with neuropsychological impairment
Pharmacol. Biochem. Behav.
(1997) - et al.
Neuropsychological improvement following endarterectomy as a function of outcome measure and reconstructed vessel
Cortex
(1988) Senile dementia—a new explanation of its causation
Can. Med. Assoc. J.
(1951)- et al.
Psychological study of carotid occlusion and endarterectomy
Arch. Neurol.
(1964) - et al.
IQ and neuropsychological changes following carotid endarterectomy
J. Clin. Neuropsychol.
(1979) - et al.
Carotid artery disease, carotid endarterectomy, and behavior
Arch. Neurol.
(1980) - et al.
Neuropsychological performance one week after carotid endarterectomy reflects intra-operative ischemia
Stroke
(1984) - et al.
Quality of life and cognitive performance after carotid endarterectomy during long-term follow-up
Acta Neurol. Scand.
(1992) - et al.
Cognitive impairment after extracranial reconstruction for the low flow-endangered brain
Surgery
(1983)
Changes in performance on WAIS, Trail marking test and finger tapping test associated with carotid artery surgery
Percept. Mot. Skills
Cerebral function before and after carotid endarterectomy
Br. Med. J.
Neuropsychological changes following carotid endarterectomy
Can. J. Neurol. Sci.
The effect of unilateral carotid endarterectomy on neuropsychological test performance in 53 patients
J. Cardiovasc. Surg.
Carotid surgery, cognitive function, and cerebral blood flow in patients with transient ischemic attacks
Ann. Neurol.
Frequency of carotid endarterectomy-related subclinical cerebral complications
Cerebrovasc. Dis.
Cited by (55)
Neurocognitive Changes After Carotid Revascularization According to Perfusion Parameters: A Meta-analysis of Current Literature
2020, Annals of Vascular SurgeryChronic cerebral hypoperfusion: An undefined, relevant entity
2020, Journal of Clinical NeuroscienceImprovement of neurovascular function and cognitive impairment after STA-MCA anastomosis
2017, Journal of the Neurological SciencesCitation Excerpt :We have reported in patients with severe steno-occlusive disease of a main cerebral artery that cognitive impairment is most likely to be associated with widespread, nonselectively decreased cerebrovascular reserve (CVR) on both sides, using COGNISTAT (the Japanese version of the neurobehavioral cognitive status examination) and iodine-123-N-isopropyl-p-iodoamphetamine single photon emission computed tomography (123IMP-SPECT) [1]. Patients with severe steno-occlusive disease of a main cerebral artery often demonstrate cognitive impairment without focal neurological deficits and without causative lesions identified on magnetic resonance imaging (MRI) [1–5]. As a mechanism of cognitive impairment, a focal decline in ipsilateral CVR has been estimated by positron emission tomography (PET) [5,6], transcranial Doppler (TCD) [1,7–9], or technetium (99mTc)-ethyl cysteinate dimer single photon emission computed tomography (ECD-SPECT) [4].
Cognitive impairment and neurovascular function in patients with severe steno-occlusive disease of a main cerebral artery
2016, Journal of the Neurological SciencesCitation Excerpt :Patients with asymptomatic severe steno-occlusive disease of an internal carotid artery (ICA) or a middle cerebral artery (MCA) often demonstrate cognitive impairment without causative lesions identified on magnetic resonance imaging (MRI) [1–4].