Postoperative Cognitive Decline Research Articles

Subjective and objective cognition 6-week post-coronary artery bypass graft surgery: A descriptive pilot study.

BackgroundCoronary artery bypass graft (CABG) surgery has been found to be associated with post-operative cognitive decline. Despite the large and growing numbers being conducted in South Africa, the associated or ensuing cognitive symptoms or impairment have received little research attention.AimThe aim of this pilot study was to describe the nature and extent of subjective cognitive complaints (SCCs) and objective cognitive impairments in patients 6-week post-CABG surgery in a clinical sample in KwaZulu-Natal (KZN) Province, South Africa.SettingA cross-sectional survey was conducted among outpatients attending their 6-week post-CABG surgical review at a cardiology clinic in a KZN provincial hospital.MethodSocio-demographic and clinical data were captured, with SCCs being determined by using standardised questions; cognition was assessed with the Montreal cognitive assessment (MoCA).ResultsThe mean age of the sample (n = 28) was 58.72 years. The mean MoCA score was 23.96 (SD = 4.32); 60.71% (n = 17) screening positive (< 25/30) and more likely to be older, male, hypertensive and diabetic. A third (n = 9; 35.71%) reported at least one new SCC; their mean age was 55.36 years which was lower than those without subjective complaints (59.81).ConclusionsSubjective and objective cognitive impairments were evident in patients 6-week post-CABG surgery identifying a need for longitudinal cognitive screening both pre- and post- operatively in patients undergoing CABG surgery.

Postoperative neurocognitive disorders.

A decline in cognitive function is a frequent complication of major surgery. Postoperative cognitive impairments have generally been divided into short- (postoperative delirium) and long-term disturbances (postoperative cognitive dysfunction [POCD]). Long-term impairments are often subtle and overlooked. They need to be objectively assessed using neuropsychological tests to be diagnosed. Although POCD has been the subject of considerable research over the past decades, it remains uncertain why some patients do not return to preoperative levels of cognitive function. Surgery and anesthesia have both been implicated to play a role in POCD development, and certain patient-related factors, such as advanced age and low preoperative baseline cognitive function, have consistently been found to predict postoperative cognitive decline. This article will present an overview of POCD and its etiology and provide advice on possible strategies on its prevention.

Blocking Kv1.3 potassium channels prevents postoperative neuroinflammation and cognitive decline without impairing wound healing in mice

BackgroundPostoperative cognitive decline (PCD) requires microglial activation. Voltage-gated Kv1.3 potassium channels are involved in microglial activation. We determined the role of Kv1.3 in PCD and the efficacy and safety of inhibiting Kv1.3 with phenoxyalkoxypsoralen-1 (PAP-1) in preventing PCD in a mouse model. MethodsAfter institutional approval, we assessed whether Kv1.3-deficient mice (Kv1.3–/–) exhibited PCD, evidenced by tibial-fracture surgery-induced decline in aversive freezing behaviour, and whether PAP-1 could prevent PCD and postoperative neuroinflammation in PCD-vulnerable diet-induced obese (DIO) mice. We also evaluated whether PAP-1 altered either postoperative peripheral inflammation or tibial-fracture healing. ResultsFreezing behaviour was unaltered in postoperative Kv1.3–/– mice. In DIO mice, PAP-1 prevented postoperative (i) attenuation of freezing behaviour (54 [17.3]% vs 33.4 [12.7]%; P=0.03), (ii) hippocampal microglial activation by size (130 [31] pixels vs 249 [49]; P<0.001) and fluorescence intensity (12 000 [2260] vs 20 800 [5080] absorbance units; P<0.001), and (iii) hippocampal upregulation of interleukin-6 (IL-6) (14.9 [5.7] vs 25.6 [10.4] pg mg−1; P=0.011). Phenoxyalkoxypsoralen-1 neither affected surgery-induced upregulation of plasma IL-6 nor cartilage and bone components of the surgical fracture callus. ConclusionsMicroglial-mediated PCD requires Kv1.3 activity, determined by genetic and pharmacological targeting approaches. Phenoxyalkoxypsoralen-1 blockade of Kv1.3 prevented surgery-induced hippocampal microglial activation and neuroinflammation in mice known to be vulnerable to PCD. Regarding perioperative safety, these beneficial effects of PAP-1 treatment occurred without impacting fracture healing. Kv1.3 blockers, currently undergoing clinical trials for other conditions, may represent an effective and safe intervention to prevent PCD.

Neurological impact of emboli during adult cardiac surgery

ObjectivesThis study draws on advances in Doppler ultrasound bubble sizing to investigate whether high volumes of macro-bubbles entering the brain during cardiac surgery increase the risk of new cerebral microbleeds (CMBs), ischemic MR lesions, or post-operative cognitive decline (POCD). MethodsTranscranial Doppler (TCD) ultrasound recordings were analysed to estimate numbers of emboli and macrobubbles (>100 μm) entering the brain during cardiac surgery. Logistic regression was used to explore the hypothesis that emboli characteristics affect the incidence of new brain injuries identified through pre- and post-operative MRI and neuropsychological testing. ResultsTCD, MRI, and neuropsychological test data were compared between 28 valve and 18 CABG patients. Although valve patients received over twice as many emboli per procedure [median: 1995 vs. 859, p = .004], and seven times as many macro-bubbles [median: 218 vs. 28, p = .001], high volumes of macrobubbles were not found to be significantly associated with new CMBs, new ischaemic lesions, or POCD. The odds of acquiring new CMBs increased by approximately 5% [95% CI: 1 to 10%] for every embolus detected in the first minute after the release of the aortic cross-clamp (AxC). Logistic regression models also confirmed previous findings that cardiopulmonary bypass time and valve surgery were significant predictors for new CMBs (both p = .03). Logistic regression analysis estimated an increase in the odds of acquiring new CMBs of 6% [95% CI: 1 to 12%] for every minute of bypass time over 91 mins. ConclusionsThis small study provides new information about the properties and numbers of bubbles entering the brain during surgery, but found no evidence to substantiate a direct link between large numbers of macrobubbles and adverse cognitive or MR outcome.Clinical Trial Registration URL - http://www.isrctn.com. Unique identifier: 66022965.

Cognitive impairment assessment and interventions to optimize surgical patient outcomes.

For elderly patients undergoing elective surgical procedures, preoperative evaluation of cognition is often overlooked. Patients may experience postoperative delirium (POD) and postoperative cognitive decline (POCD), especially those with certain risk factors, including advanced age. Preoperative cognitive impairment is a leading risk factor for both POD and POCD, and studies have noted that identifying these deficiencies is critical during the preoperative period so that appropriate preventive strategies can be implemented. Comprehensive geriatric assessment is a useful approach which evaluates a patient's medical, psycho-social, and functional domains objectively. Various screening tools are available for preoperatively identifying patients with cognitive impairment. The Enhanced Recovery After Surgery (ERAS) protocols have been discussed in the context of prehabilitation as an effort to optimize a patient's physical status prior to surgery and decrease the risk of POD and POCD. Evidence-based protocols are warranted to standardize care in efforts to effectively meet the needs of these patients.

Natriuretic Peptides as a Prognostic Marker for Delirium in Cardiac Surgery-A Pilot Study.

Background and Objectives: Delirium is a common and major complication subsequent to cardiac surgery. Despite scientific efforts, there are no parameters which reliably predict postoperative delirium. In delirium pathology, natriuretic peptides (NPs) interfere with the blood–brain barrier and thus promote delirium. Therefore, we aimed to assess whether NPs may predict postoperative delirium and long-term outcomes. Materials and Methods: To evaluate the predictive value of NPs for delirium we retrospectively analyzed data from a prospective, randomized study for serum levels of atrial natriuretic peptide (ANP) and the precursor of C-type natriuretic peptide (NT-proCNP) in patients undergoing coronary artery bypass grafting (CABG) with or without cardiopulmonary bypass (off-pump coronary bypass grafting; OPCAB). Delirium was assessed by a validated chart-based method. Long-term outcomes were assessed 10 years after surgery by a telephone interview. Results: The overall incidence of delirium in the total cohort was 48% regardless of the surgical approach (CABG vs. OPCAB). Serum ANP levels > 64.6 pg/mL predicted delirium with a sensitivity (95% confidence interval) of 100% (75.3–100) and specificity of 42.9% (17.7–71.1). Serum NT-proCNP levels >1.7 pg/mL predicted delirium with a sensitivity (95% confidence interval) of 92.3% (64.0–99.8) and specificity of 42.9% (17.7–71.1). Both NPs could not predict postoperative survival or long-term cognitive decline. Conclusions: We found a positive correlation between delirium and preoperative plasma levels of ANP and NT-proCNP. A well-powered and prospective study might identify NPs as biomarkers indicating the risk of delirium and postoperative cognitive decline in patients at risk for postoperative delirium.

Does laparoscopic colorectal surgery result in short and long term post-operative cognitive decline (POCD)?

Postoperative cognitive decline (POCD) is defined as a new cognitive impairment arising after surgical intervention. There is some concern that prolonged Trendelenburg positioning during laparoscopic colorectal surgery may cause POCD. Patients with POCD may experience prolonged hospitalisation and take longer returning to their normal level of functioning.Cognitive function can be assessed using validated tests including: N Back, Stroop; and Lexical Decision Making Task. AimTo assess percentage of short and long-term POCD following laparoscopic colorectal surgery. Assess the effect of time spent in Trendelenburg position on developing POCD. MethodsPatients undergoing laparoscopic colorectal surgery were recruited. Cognitive tests including: 1, 2 and 3 back, lexical decision making task and stroop task were carried out pre-operatively and repeated Day 1, and minimum 3 months post-operatively. For assessment of POCD Day 1, the baseline was subtracted from Day 1 results for each test. This result was then divided by the standard deviation of the control group to give a Z score. A large positive Z score (>1.96) showed a deterioration in cognitive function from baseline for accuracy, and a large negative Z score (> -1.96) for response time. An individual Z score of 1.96 or more was defined as cognitive dysfunction. ResultsForty-six patients were recruited (26 males, 24 female), mean age 66 years (SD± 5.18). Of which 55% had POCD on Day 1; and 37 patients completed long-term follow up of which 32% had POCD. ConclusionOur study does show a significant number of patients develop both long and short term POCD following laparoscopic colorectal surgery.

Evaluation of the risk factors for neurological and neurocognitive impairment after selective cerebral perfusion in thoracic aortic surgery.

Neurologic complications are seen often after the surgery of the thoracic aorta that uses selective antegrade cerebral perfusion. The objective of this study was to evaluate the impact of atherosclerotic risk factors on neurologic complications in patients who underwent surgery to the thoracic aorta using SCP. Data were collected retrospectively on 94 patients who underwent elective ascending aorta/aortic arch replacement. Concomitant procedures were performed as needed. All patients had magnetic resonance imaging (MRI), angiography (MRA) and carotid ultrasound before surgery. Individual cognitive status was measured using four neuropsychological tests before surgery and 7days after extubation. We compared perioperative factors for risk factors associated with postoperative stroke and postoperative cognitive decline (POCD). 11 patients had strokes after surgery. Operation and extracorporeal circulation times were significantly longer in patients with stroke than those without stroke. Coronary artery disease and SCP time > 150min were independently associated with postoperative stroke. Of the 83 patients without postoperative stroke, 20 suffered POCD. POCD patients had a significantly higher rate of heterogeneous carotid plaque, and operation time was significant longer in patients with POCD than those without POCD. Independent predictors of POCD were concomitant CABG, heterogeneous carotid plaque, history of cerebrovascular disease and operation time > 450min. We found that prolonged SCP time and coronary artery disease increased the risk of postoperative stroke. Heterogeneous carotid plaque, history of cerebrovascular disease, concomitant CABG and prolonged operation time were further significant predictors of POCD.

Does Postoperative Cognitive Decline Result in New Disability After Surgery?

Establish whether POCD is associated with new disability after surgery, which would inform whether POCD impacts patient-centered outcomes. POCD is a decline in neuropsychiatric tests scores from presurgical baseline which occurs in approximately 15% of older patients 3 months after surgery. POCD is a research construct meant to investigate patient and family reports of older adults who were "never the same after surgery." However, many patients with POCD do not perceive difficulty with thinking and memory, and the question remains whether POCD impacts patient function. We performed a prospective cohort study of 167 older adults undergoing major noncardiac surgery (requiring at least a 2-day hospital stay). Exclusion criteria were: history of dementia, cardiac or intracranial procedure, inability to consent for themselves, or emergency surgery. We administered formal neuropsychiatric testing (Alzheimer Disease Research Center UDS battery), basic and instrumental activities of daily living (Alzheimer Disease Research Center IADLs), pain (geriatric pain measure), and depression screening (hospital depression and anxiety scale) before and 3 months after surgery. We recorded all patient refined diagnostic related groups codes, blood pressure, anesthetics and narcotics administered, surgical and anesthesia duration, and measured complications and severity, length of stay, and readmissions. Patients with POCD (21/167, 14.1%) had twice the proportion of new impairment in IADL as compared to those without POCD (57% vs 27%, P = .01). The most common areas of decline were social activities, ability to find items around the house, remember appointments, shop and pay for items, do laundry, drive a car/use public transport, and do housework. Predictors of IADL change after surgery included POCD, presurgical cognition, presurgical function, postoperative depression, and the development of postoperative complications. Patients with POCD experience a much higher incidence of new disability after surgery. Baseline cognitive or functional limitations are also risk factors for new disability. Many patients are not aware of their limitations before surgery. Future study is needed to identify practical ways to routinely screen patients and reduce risk. Patients need to be informed of their risk for new disability after surgery to inform their medical decision making.

Dysfunction of inflammation-resolving pathways is associated with postoperative cognitive decline in elderly mice

BackgroundPostoperative cognitive dysfunction (POCD) refers to a reversible, perioperative mental disorder. POCD increases the likelihood of postoperative complications and the risk for postoperative mortality, typically among elderly patients (age 65 or older). The importance of the cholinergic anti-inflammatory pathway (CAP) in resolving neuro-inflammatory and cognitive decline caused by sterile trauma has been recognized. We speculate that the POCD in elderly mice is associated with dysfunction of CAP. MethodsMice were assigned to several groups (n = 5 in each group): AM (adult mice) Sham, AM (adult mice) Surgery, EM (elderly mice) Sham, EM (elderly mice) Surgery, and EMP (elderly mice with PNU) Surgery. At 24 h after surgery, assessed the cognitive levels. Pro-inflammatory cytokines in peripheral blood and splenic monocytes (TNF-α, IL-6 and IL-10) were assessed by ELISA and qPCR. Levels of M2 macrophages in hippocampus were visualized by immunofluorescence. Detecting CD11b/c+α7 nAChR+ cells in the spleens with flow cytometry. ResultsAt postoperative 24 h, elderly mice exhibited significantly increased POCD compared with adult mice. The proinflammatory factor TNF-α and IL-6 were higher among elderly surgery mice (EM) compared with adult surgery (AM) and elderly-P surgery mice (EM-P); the anti-inflammatory factor IL-10 and M2 macrophages were lower among EM surgery mice compared with AM surgery and EM-P surgery mice. The CD11b/c+α7 nAChR+ population of splenocytes was reduced in the EM surgery mice. ConclusionsThe exaggerated and persistent cognitive decline and inflammatory response among elderly mice were associated with dysfunction of CAP, and these phenomena were reversed by α7nAch receptor agonists.

Is the bispectral index monitoring protective against postoperative cognitive decline? A systematic review with meta-analysis.

Several studies have suggested that monitoring the depth of anaesthesia might prevent the development of postoperative cognitive decline. We aimed to conduct a meta-analysis to investigate the effects of bispectral index (BIS) monitoring in anaesthesia. We searched in six major electronic databases. Trials were included if they discussed anaesthesia with and without BIS monitoring or low (<50) and high (≥50) BIS levels and which measured the risk of postoperative delirium (POD) and/or postoperative cognitive dysfunction (POCD). We included fourteen studies in the systematic review, eight of which were eligible for meta-analysis. BIS proved to be protective against POD at 1 day postoperatively in a cohort of 2138 patients (16.1% vs. 22.8% for BIS vs. no BIS groups, respectively; relative risk [RR] 0.71; 95% confidence interval [CI] 0.59 to 0.85, without significant between-study heterogeneity I2 = 0.0%, P = 0.590). The use of BIS was neutral for POCD at 1 week but protective for POCD at 12 weeks (15.8% vs. 18.8% for BIS vs. no BIS groups, respectively; RR = 0.84, CI: 0.66 to 1.08), without significant between-study heterogeneity (I2 = 25.8%, P = 0.260). The neutral association at 1 week proved to be underpowered with trial sequential analysis. In the comparison of low BIS versus high BIS, the incidence of POD at 1 day was similar in the groups. Our findings suggest a protective effect of BIS compared to not using BIS regarding the incidence of POD at 1 day and POCD at 12 weeks. However, limitations of the evidence warrant further investigation to identify those groups of patients by age, comorbid conditions and other individual variables who would benefit the most from the use of BIS monitoring.

Perioperative care of people with dementia.

As the population ages, there is a higher prevalence of both dementia and conditions that require major surgery. However, patients with dementia undergoing surgery have poorer outcomes than surgical patients without dementia. This article explores new guidance about delivering perioperative care for patients with dementia presenting for surgery. Management of patients with cognitive changes begins with developing an understanding of the classifications and pathophysiology of these disease processes, and addressing any modifiable risk factors for developing dementia, postoperative cognitive decline and postoperative delirium. Thorough preoperative assessment provides the opportunity to identify patients with and at risk of these cognitive impairments and to involve the appropriate multidisciplinary team in care planning. Once patients are identified, an individualised perioperative management plan addressing any issues surrounding capacity and consent, conduct of anaesthesia, possible polypharmacy and potential drug interactions, and postoperative pain management can improve quality of care and outcomes for these patients.

Computerised cognitive training to improve cognition including delirium following coronary artery bypass grafting surgery: protocol for a blinded randomised controlled trial

IntroductionCoronary artery bypass grafting (CABG) surgery is known to improve vascular function and cardiac-related mortality rates; however, it is associated with high rates of postoperative cognitive decline and delirium. Previous...

Postoperative neurocognitive disorders.

Alterations in cognitive functions are common in the perioperative course. Although often unnoticed by physicians, these alterations might have distinct long-term consequences for the patient with regard to everyday functioning, self-dependency, and quality of life. In recent years, however, perioperative cognition has gained increased interest, both by clinicians and scientists, and knowledge of the preventive measures of postoperative cognitive decline has become mandatory for anesthetists and surgeons. This review offers a brief overview of the current state of knowledge concerning perioperative changes in cognition, including its pathophysiology and prevention strategies. Postoperative neurocognitive disorders are frequent complications, especially in elderly patients, with postoperative delirium being its most pronounced and acute postoperative form, predisposing the patient for long-term cognitive impairment. The incidence of postoperative cognitive decline can be reduced by implementing preventive measures during perioperative patient care as recommended by national and international guidelines.

Neurological dysfunction after cardiac surgery and cardiac intensive care admission: A narrative review part 1: The problem; nomenclature; delirium and postoperative neurocognitive disorder; and the role of cardiac surgery and anesthesia

The association with cardiac surgery with cognitive decline was first reported in the 1960s after the introduction of coronary artery surgery. The incidence in cognitive decline was thought to be more after cardiac surgery, especially with the use of the cardiopulmonary bypass. Anesthesia and surgery are both associated with cognitive decline but many other factors appear to contribute its genesis. On-pump surgery, microembolization during manipulation of the heart and great vessels, temperature changes, pH changes, and altered cerebral perfusion, during cardiac surgery, have all been blamed for this. Postoperative cognitive decline is associated with poor clinical outcomes and higher mortality. Several studies have been conducted in the last decade to determine the genesis of this malady. Current evidence is absolving cardiac surgery and anesthesia to be the primary causes per se of cognitive dysfunction.

Substitution of propofol for dexmedetomidine in the anaesthetic regimen does not ameliorate the post-operative cognitive decline in elderly patients

Background and Aims:Post-operative cognitive dysfunction (POCD) is a poorly understood complication particularly observed in elderly patients, with long-term poor outcome. The randomised study was to compare the incidence of POCD in elderly with bispectral index (BIS)-guided intra-operative use of either dexmedetomidine or propofol with sevoflurane.Methods:Eighty-seven patients, planned for non-cardiac surgery under general anaesthesia, were included between June 2017 and March 2018. After exclusion of 7 patients, remaining 80 patients were randomised into dexmedetomidine group and propofol group with 40 patients each. In both the groups, BIS-guided anaesthesia was provided. Cognitive function was assessed by an anaesthesiologist using a battery of neuropsychological tests at baseline pre-operatively, third and seventh day after surgery. The data were entered into a Microsoft Excel spreadsheet and analysis was performed using Statistical Package for Social Sciences (SPSS) version 21.Results:Propofol group had a non-significant lower incidence of POCD on third day and dexmedetomidine group showed decreased incidence of POCD on seventh day, accompanied by lower anaesthetic requirement (inhalational as well as intravenous) concomitant with delayed emergence with an acceptable BIS value.Conclusion:Dexmedetomidine appeared to be anaesthetic sparing as compared to propofol. BIS monitoring for titrating depth of anaesthesia and hence the anaesthetic exposure is an invaluable tool as compared to routine care anaesthesia for reducing POCD. The patients in both groups did not develop significant POCD until the seventh post-operative day.

Near-Infrared Spectroscopy Monitoring in Cardiac and Noncardiac Surgery: Pairwise and Network Meta-Analyses.

Goal-directed therapy based on brain-oxygen saturation (bSo2) is controversial and hotly debated. While meta-analyses of aggregated data have shown no clinical benefit for brain near-infrared spectroscopy (NIRS)-based interventions after cardiac surgery, no network meta-analyses involving both major cardiac and noncardiac procedures have yet been undertaken. Randomized controlled trials involving NIRS monitoring in both major cardiac and noncardiac surgery were included. Aggregate-level data summary estimates of critical outcomes (postoperative cognitive decline (POCD)/postoperative delirium (POD), acute kidney injury, cardiovascular events, bleeding/need for transfusion, and postoperative mortality) were obtained. NIRS was only associated with protection against POCD/POD in cardiac surgery patients (pooled odds ratio (OR)/95% confidence interval (CI)/I2/number of studies (n): 0.34/0.14–0.85/75%/7), although a favorable effect was observed in the analysis, including both cardiac and noncardiac procedures. However, the benefit of the use of NIRS monitoring was undetectable in Bayesian network meta-analysis, although maintaining bSo2 > 80% of the baseline appeared to have the most pronounced impact. Evidence was imprecise regarding acute kidney injury, cardiovascular events, bleeding/need for transfusion, and postoperative mortality. There is evidence that brain NIRS-based algorithms are effective in preventing POCD/POD in cardiac surgery, but not in major noncardiac surgery. However, the specific target bSo2 threshold has yet to be determined.

Cognitive decline after carotid endarterectomy: Systematic review and meta-analysis.

Postoperative cognitive decline (pCD) occurs frequently (6 to 30%) after carotid endarterectomy (CEA), although there are no exact estimates and risk factors are still unclear. The objective of this study was to determine pCD incidence and risk factors in CEA patients. We performed a systematic review and meta-analysis of both randomised and nonrandomised trials following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched Cochrane, PubMed/Medline and Embase databases from the date of database inception to 1 December 2018. We selected longitudinal studies including CEA patients with both pre-operative and postoperative cognitive assessments. Primary outcome was pCD incidence, differentiating delayed neurocognitive recovery (dNCR) and postoperative neurocognitive disorder (pNCD). dNCR and pNCD incidences were expressed as proportions of cases on total CEA sample and pooled as weighted estimates from proportions. Postoperative delirium was excluded from the study design. Secondary outcomes were patient-related (i.e. age, sex, diabetes, hypertension, contralateral stenosis, pre-operative symptoms, dyslipidaemia and statin use) and procedure-related (i.e. hyperperfusion, cross-clamping duration and shunting placement) risk factors for pCD. We estimated odds ratios (ORs) and mean differences through a random effects model by using STATA 13.1 and RevMan 5.3. Our search identified 5311 publications and 60 studies met inclusion criteria reporting a total of 4823 CEA patients. dNCR and pNCD incidence were 20.5% [95% confidence interval (CI), 17.1 to 24.0] and 14.1% (95% CI, 9.5 to 18.6), respectively. pCD risk was higher in patients experiencing hyperperfusion during surgery (OR, 35.68; 95% CI, 16.64 to 76.51; P < 0.00001; I = 0%), whereas dNCR risk was lower in patients taking statins before surgery (OR, 0.56; 95% CI, 0.41 to 0.77; P = 0.0004; I = 19%). Sensitivity analysis revealed that longer cross-clamping duration was a predictor for dNCR (mean difference, 5.25 min; 95% CI, 0.87 to 9.63; P = 0.02; I = 49%). We found high incidences of dNCR (20.5%) and pNCD (14.1%) after CEA. Hyperperfusion seems to be a risk factor for pCD, whereas the use of statins is associated with a lower risk of dNCR. An increased cross-clamping duration could be a risk factor for dNCR. This systematic review was registered in the International Prospective Register of Systematic Reviews (CDR42017073633).

Patients’ experiences of early postoperative cognition and its relation to cognitive decline and inflammatory responses: a protocol for a mixed-methods study

IntroductionIn the early weeks after surgery, patients may experience cognitive changes and impaired memory and concentration—changes commonly referred to as postoperative cognitive decline. It is often the patient and/or a...

Impact of cerebral blood flow changes due to arterial bypass surgery on cognitive function in adult patients with symptomatic ischemic moyamoya disease.

Some adult patients with moyamoya disease (MMD) undergoing revascularization surgery show an improvement or decline in cognition postoperatively. Revascularization surgery for ischemic MMD augments cerebral blood flow (CBF) and improves cerebral oxygen metabolism. However, cerebral hyperperfusion, which is a short-term, major increase in ipsilateral CBF that is much greater than the metabolic needs of the brain, sometimes occurs as a complication. Cerebral hyperperfusion produces widespread, minimal injury to the ipsilateral white matter and cortical regions. The aim of the present prospective study was to determine how changes in CBF due to arterial bypass surgery affect cognitive function in adult patients with symptomatic ischemic MMD and misery perfusion. Thirty-two patients with cerebral misery perfusion, as determined on the basis of 15O gas positron emission tomography, underwent single superficial temporal artery-middle cerebral artery (M4 in the precentral region) anastomosis. Brain perfusion single-photon emission computed tomography (SPECT) studies were performed preoperatively, on the 1st postoperative day, and 2 months after surgery. Neuropsychological tests were also performed preoperatively and 2 months after surgery. Postoperative neuropsychological assessments demonstrated cognitive improvement in 10 cases (31%), no change in 8 cases (25%), and decline in 14 cases (44%). Based on brain perfusion SPECT and symptoms, 10 patients were considered to have cerebral hyperperfusion syndrome, and all of these patients exhibited a postoperative decline in cognition. Relative precentral CBF on the 1st postoperative day was significantly greater in patients with postoperative cognitive decline (167.3% ± 15.3%) than in those with improved (105.3% ± 18.2%; p < 0.0001) or unchanged (131.4% ± 32.1%; p = 0.0029) cognition. The difference between relative precentral CBF 2 months after surgery and that before surgery was significantly greater in patients with postoperative cognitive improvement (17.2% ± 3.8%) than in those with no postoperative change (10.1% ± 2.4%; p = 0.0003) or with postoperative decline (11.5% ± 3.2%; p = 0.0009) in cognition. Cerebral hyperperfusion in the acute stage after arterial bypass surgery impairs cognitive function. An increase in CBF in the chronic stage without acute-stage cerebral hyperperfusion improves cognitive function in adult patients with symptomatic ischemic MMD and misery perfusion.