Recommendations for the Nomenclature of Cognitive Change Associated with Anaesthesia and Surgery-2018.

Cognitive change affecting patients after anaesthesia and surgery has been recognised for more than 100 yr. Research into cognitive change after anaesthesia and surgery accelerated in the 1980s when multiple studies utilised detailed neuropsychological testing for assessment of cognitive change after cardiac surgery. This body of work consistently documented decline in cognitive function in elderly patients after anaesthesia and surgery, and cognitive changes have been identified up to 7.5 yr afterwards. Importantly, other studies have identified that the incidence of cognitive change is similar after non-cardiac surgery. Other than the inclusion of non-surgical control groups to calculate postoperative cognitive dysfunction, research into these cognitive changes in the perioperative period has been undertaken in isolation from cognitive studies in the general population. The aim of this work is to develop similar terminology to that used in cognitive classifications of the general population for use in investigations of cognitive changes after anaesthesia and surgery. A multispecialty working group followed a modified Delphi procedure with no prespecified number of rounds comprised of three face-to-face meetings followed by online editing of draft versions.Two major classification guidelines (Diagnostic and Statistical Manual for Mental Disorders, fifth edition [DSM-5] and National Institute for Aging and the Alzheimer Association [NIA-AA]) are used outside of anaesthesia and surgery, and may be useful for inclusion of biomarkers in research. For clinical purposes, it is recommended to use the DSM-5 nomenclature. The working group recommends that 'perioperative neurocognitive disorders' be used as an overarching term for cognitive impairment identified in the preoperative or postoperative period. This includes cognitive decline diagnosed before operation (described as neurocognitive disorder); any form of acute event (postoperative delirium) and cognitive decline diagnosed up to 30 days after the procedure (delayed neurocognitive recovery) and up to 12 months (postoperative neurocognitive disorder).

Tau uptake in agrammatic primary progressive aphasia with and without apraxia of speech.

BACKGROUND AND PURPOSE: The non-fluent/agrammatic variant of primary progressive aphasia (agPPA) is a heterogeneous diagnosis wherein some individuals have apraxia of speech (AOS). When agPPA includes AOS, a tauopathy is the likely underlying pathology. Recently, [18F]AV-1451 was developed for the in-vivo assessment of tau. In this study, we compared patterns of tau tracer uptake in patients with agPPA with and without AOS. METHODS: Nine patients with agPPA (four without AOS) underwent tau positron emission tomography imaging with [18F]AV-1451. Uptake of [18F]AV-1451 was assessed as cortical to cerebellar crus ratio (standard uptake value ratio) in cortical regions of interest measured using the MCALT atlas and compared voxel-wise in SPM12. Each patient was age- and sex-matched to three controls. RESULTS: The agPPA without AOS showed uptake in the left frontal and temporal lobes, whereas agPPA with AOS showed uptake in the bilateral supplementary motor areas, frontal lobes, precuneus and precentral gyrus relative to controls. The left precentral gyrus had uptake in agPPA with AOS relative to those without AOS. CONCLUSIONS: This cross-sectional study suggests that [18F]AV-1451 uptake in the precentral gyrus is implicated in AOS in agPPA.

Association between exposure to anaesthesia and surgery and long-term cognitive trajectories in older adults: report from the Mayo Clinic Study of Aging.

BACKGROUND: The link between exposure to general anaesthesia and surgery (exposure) and cognitive decline in older adults is debated. We hypothesised that it is associated with cognitive decline. METHODS: We analysed the longitudinal cognitive function trajectory in a cohort of older adults. Models assessed the rate of change in cognition over time, and its association with exposure to anaesthesia and surgery. Analyses assessed whether exposure in the 20 yr before enrolment is associated with cognitive decline when compared with those unexposed, and whether post-enrolment exposure is associated with a change in cognition in those unexposed before enrolment. RESULTS: We included 1819 subjects with median (25th and 75th percentiles) follow-up of 5.1 (2.7-7.6) yr and 4 (3-6) cognitive assessments. Exposure in the previous 20 yr was associated with a greater negative slope compared with not exposed (slope: -0.077 vs -0.059; difference: -0.018; 95% confidence interval: -0.032, -0.003; P=0.015). Post-enrolment exposure in those previously unexposed was associated with a change in slope after exposure (slope: -0.100 vs -0.059 for post-exposure vs pre-exposure, respectively; difference: -0.041; 95% confidence interval: -0.074, -0.008; P=0.016). Cognitive impairment could be attributed to declines in memory and attention/executive cognitive domains. CONCLUSIONS: In older adults, exposure to general anaesthesia and surgery was associated with a subtle decline in cognitive z-scores. For an individual with no prior exposure and with exposure after enrolment, the decline in cognitive function over a 5 yr period after the exposure would be 0.2 standard deviations more than the expected decline as a result of ageing. This small cognitive decline could be meaningful for individuals with already low baseline cognition.

Recommendations for the nomenclature of cognitive change associated with anaesthesia and surgery-2018.

Cognitive change affecting patients after anaesthesia and surgery has been recognised for more than 100 yr. Research into cognitive change after anaesthesia and surgery accelerated in the 1980s when multiple studies utilised detailed neuropsychological testing for assessment of cognitive change after cardiac surgery. This body of work consistently documented decline in cognitive function in elderly patients after anaesthesia and surgery, and cognitive changes have been identified up to 7.5 yr afterwards. Importantly, other studies have identified that the incidence of cognitive change is similar after non-cardiac surgery. Other than the inclusion of non-surgical control groups to calculate postoperative cognitive dysfunction, research into these cognitive changes in the perioperative period has been undertaken in isolation from cognitive studies in the general population. The aim of this work is to develop similar terminology to that used in cognitive classifications of the general population for use in investigations of cognitive changes after anaesthesia and surgery. A multispecialty working group followed a modified Delphi procedure with no prespecified number of rounds comprised of three face-to-face meetings followed by online editing of draft versions. Two major classification guidelines [Diagnostic and Statistical Manual for Mental Disorders, fifth edition (DSM-5) and National Institute for Aging and the Alzheimer Association (NIA-AA)] are used outside of anaesthesia and surgery, and may be useful for inclusion of biomarkers in research. For clinical purposes, it is recommended to use the DSM-5 nomenclature. The working group recommends that 'perioperative neurocognitive disorders' be used as an overarching term for cognitive impairment identified in the preoperative or postoperative period. This includes cognitive decline diagnosed before operation (described as neurocognitive disorder); any form of acute event (postoperative delirium) and cognitive decline diagnosed up to 30 days after the procedure (delayed neurocognitive recovery) and up to 12 months (postoperative neurocognitive disorder).

Recommendations for the Nomenclature of Cognitive Change Associated With Anaesthesia and Surgery-2018.

Cognitive change affecting patients after anaesthesia and surgery has been recognised for more than 100 yr. Research into cognitive change after anaesthesia and surgery accelerated in the 1980s when multiple studies utilised detailed neuropsychological testing for assessment of cognitive change after cardiac surgery. This body of work consistently documented decline in cognitive function in elderly patients after anaesthesia and surgery, and cognitive changes have been identified up to 7.5 yr afterwards. Importantly, other studies have identified that the incidence of cognitive change is similar after non-cardiac surgery. Other than the inclusion of non-surgical control groups to calculate postoperative cognitive dysfunction, research into these cognitive changes in the perioperative period has been undertaken in isolation from cognitive studies in the general population. The aim of this work is to develop similar terminology to that used in cognitive classifications of the general population for use in investigations of cognitive changes after anaesthesia and surgery. A multispecialty working group followed a modified Delphi procedure with no prespecified number of rounds comprised of three face-to-face meetings followed by online editing of draft versions.Two major classification guidelines [Diagnostic and Statistical Manual for Mental Disorders, fifth edition (DSM-5) and National Institute for Aging and the Alzheimer Association (NIA-AA)] are used outside of anaesthesia and surgery, and may be useful for inclusion of biomarkers in research. For clinical purposes, it is recommended to use the DSM-5 nomenclature. The working group recommends that 'perioperative neurocognitive disorders' be used as an overarching term for cognitive impairment identified in the preoperative or postoperative period. This includes cognitive decline diagnosed before operation (described as neurocognitive disorder); any form of acute event (postoperative delirium) and cognitive decline diagnosed up to 30 days after the procedure (delayed neurocognitive recovery) and up to 12 months (postoperative neurocognitive disorder).

Recommendations for the nomenclature of cognitive change associated with anaesthesia and surgery-2018.

Cognitive change affecting patients after anaesthesia and surgery has been recognised for more than 100 yr. Research into cognitive change after anaesthesia and surgery accelerated in the 1980s when multiple studies utilised detailed neuropsychological testing for assessment of cognitive change after cardiac surgery. This body of work consistently documented decline in cognitive function in elderly patients after anaesthesia and surgery, and cognitive changes have been identified up to 7.5 yr afterwards. Importantly, other studies have identified that the incidence of cognitive change is similar after non-cardiac surgery. Other than the inclusion of non-surgical control groups to calculate postoperative cognitive dysfunction, research into these cognitive changes in the perioperative period has been undertaken in isolation from cognitive studies in the general population. The aim of this work is to develop similar terminology to that used in cognitive classifications of the general population for use in investigations of cognitive changes after anaesthesia and surgery. A multispecialty working group followed a modified Delphi procedure with no prespecified number of rounds comprised of three face-to-face meetings followed by online editing of draft versions.Two major classification guidelines [Diagnostic and Statistical Manual for Mental Disorders, fifth edition (DSM-5) and National Institute for Aging and the Alzheimer Association (NIA-AA)] are used outside of anaesthesia and surgery, and may be useful for inclusion of biomarkers in research. For clinical purposes, it is recommended to use the DSM-5 nomenclature. The working group recommends that 'perioperative neurocognitive disorders' be used as an overarching term for cognitive impairment identified in the preoperative or postoperative period. This includes cognitive decline diagnosed before operation (described as neurocognitive disorder); any form of acute event (postoperative delirium) and cognitive decline diagnosed up to 30 days after the procedure (delayed neurocognitive recovery) and up to 12 months (postoperative neurocognitive disorder).

Clinicopathologic heterogeneity in frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) due to microtubule-associated protein tau (MAPT) p.P301L mutation, including a patient with globular glial tauopathy.

AIM: The p.P301L mutation in microtubule-associated protein tau (MAPT) is a common cause of frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17). We compare clinicopathologic features of five unrelated and three related (brother, sister and cousin) patients with FTDP-17 due to p.P301L mutation. METHODS: Genealogical, clinical, neuropathologic and genetic data were reviewed from eight individuals. RESULTS: The series consisted of five men and three women with an average age of death of 58 years (52-65 years) and average disease duration of 9 years (3-14 years). The first symptoms were those of behavioural variant frontotemporal dementia in seven patients and semantic variant of primary progressive aphasia in one. Three patients were homozygous for the MAPT H1 haplotype; five had H1/H2 genotype. The apolipoprotein E genotype was ϵ3/ϵ3 in seven and ϵ3/ϵ4 in one. The average brain weight was 1015 g (876-1188 g). All had frontotemporal lobar or more diffuse cortical atrophy. Except for one patient, the hippocampus and parahippocampal gyrus had minimal atrophy, whereas there was atrophy of middle and inferior temporal gyri. Dentate fascia neuronal dispersion was identified in three patients, two of whom had epilepsy. In one patient there was extensive white matter tau involvement with Gallyas-positive globular glial inclusions typical of globular glial tauopathy (GGT). CONCLUSIONS: This clinicopathologic study shows inter- and intra-familial clinicopathologic heterogeneity of FTDP-17 due to MAPT p.P301L mutation, including GGT in one patient.

Postoperative delirium in elderly patients is associated with subsequent cognitive impairment.

BACKGROUND: We examined the risk for postoperative delirium (POD) in patients with mild cognitive impairment (MCI) or dementia, and the association between POD and subsequent development of MCI or dementia in cognitively normal elderly patients. METHODS: Patients ≥65 yr of age enrolled in the Mayo Clinic Study of Aging who were exposed to any type of anaesthesia from 2004 to 2014 were included. Cognitive status was evaluated before and after surgery by neuropsychological testing and clinical assessment, and was defined as normal or MCI/dementia. Postoperative delirium was detected with the Confusion Assessment Method for the intensive care unit. Logistic regression analyses were performed. RESULTS: Among 2014 surgical patients, 74 (3.7%) developed POD. Before surgery, 1667 participants were cognitively normal, and 347 met MCI/dementia criteria. The frequency of POD was higher in patients with pre-existing MCI/dementia compared with no MCI/dementia {8.7 vs 2.6%; odds ratio (OR) 2.53, [95% confidence interval (CI) 1.52-4.21]; P <0.001}. Postoperative delirium was associated with lower education [OR, 3.40 (95% CI, 1.60-7.40); P =0.002 for those with <12 vs ≥16 yr of schooling]. Of the 1667 patients cognitively normal at their most recent assessment, 1152 returned for postoperative evaluation, and 109 (9.5%) met MCI/dementia criteria. The frequency of MCI/dementia at the first postoperative evaluation was higher in patients who experienced POD compared with those who did not [33.3 vs 9.0%; adjusted OR, 3.00 (95% CI, 1.12-8.05); P =0.029]. CONCLUSIONS: Mild cognitive impairment or dementia is a risk for POD. Elderly patients who have not been diagnosed with MCI or dementia but experience POD are more likely to be diagnosed subsequently with MCI or dementia.

Brain atrophy over time in genetic and sporadic frontotemporal dementia: a study of 198 serial magnetic resonance images.

BACKGROUND AND PURPOSE: The aim of our study was to determine the utility of longitudinal magnetic resonance imaging (MRI) measurements as potential biomarkers in the main genetic variants of frontotemporal dementia (FTD), including microtubule-associated protein tau (MAPT) and progranulin (GRN) mutations and C9ORF72 repeat expansions, as well as sporadic FTD. METHODS: In this longitudinal study, 58 subjects were identified who had at least two MRI and MAPT mutations (n = 21), GRN mutations (n = 11), C9ORF72 repeat expansions (n = 11) or sporadic FTD (n = 15). A total of 198 serial MRI measurements were analyzed. Rates of whole brain atrophy were calculated using the boundary shift integral. Regional rates of atrophy were calculated using tensor-based morphometry. Sample size estimates were calculated. RESULTS: Progressive brain atrophy was observed in all groups, with fastest rates of whole brain atrophy in GRN, followed by sporadic FTD, C9ORF72 and MAPT. All variants showed greatest rates in the frontal and temporal lobes, with parietal lobes also strikingly affected in GRN. Regional rates of atrophy across all lobes were greater in GRN compared to the other groups. C9ORF72 showed greater rates of atrophy in the left cerebellum and right occipital lobe than MAPT, and sporadic FTD showed greater rates in the anterior cingulate than C9ORF72 and MAPT. Sample size estimates were lowest using temporal lobe rates in GRN, ventricular rates in MAPT and C9ORF72, and whole brain rates in sporadic FTD. CONCLUSION: These data support the utility of using rates of atrophy as outcome measures in future drug trials in FTD and show that different imaging biomarkers may offer advantages in the different variants of FTD.

Vitamin D and cognitive function and dementia risk in a biracial cohort: the ARIC Brain MRI Study.

BACKGROUND AND PURPOSE: Some recent studies in older, largely white populations suggest that vitamin D, measured by 25-hydroxyvitamin D [25(OH)D], is important for cognition, but such results may be affected by reverse causation. Measuring 25(OH)D in late middle age before poor cognition affects behavior may provide clearer results. METHODS: This was a prospective cohort analysis of 1652 participants (52% white, 48% black) in the Atherosclerosis Risk in Communities (ARIC) Brain MRI Study. 25(OH)D was measured from serum collected in 1993-1995. Cognition was measured by the delayed word recall test (DWRT), the digit symbol substitution test (DSST) and the word fluency test (WFT). Dementia hospitalization was defined by ICD-9 codes. Adjusted linear, logistic and Cox proportional hazards models were used. RESULTS: Mean age of participants was 62 years and 60% were female. Mean 25(OH)D was higher in whites than blacks (25.5 vs. 17.3 ng/ml, P < 0.001). Lower 25(OH)D was not associated with lower baseline scores or with greater DWRT, DSST or WFT decline over a median of 3 or 10 years of follow-up (P > 0.05). Over a median of 16.6 years, there were 145 incident hospitalized dementia cases. Although not statistically significant, lower levels of 25(OH)D were suggestive of an association with increased dementia risk [hazard ratio for lowest versus highest race-specific tertile: whites 1.32 (95% confidence interval 0.69, 2.55); blacks 1.53 (95% confidence interval 0.84, 2.79)]. CONCLUSIONS: In contrast to prior studies performed in older white populations, our study of late middle age white and black participants did not find significant associations between lower levels of 25(OH)D with lower cognitive test scores at baseline, change in scores over time or dementia risk.

Continuous Associations between Remote Self-Administered Cognitive Measures and Imaging Biomarkers of Alzheimer's Disease.

BACKGROUND: Easily accessible and self-administered cognitive assessments that can aid early detection for Alzheimer's disease (AD) dementia risk are critical for timely intervention. OBJECTIVES/DESIGN: This cross-sectional study investigated continuous associations between Mayo Test Drive (MTD) - a remote, self-administered, multi-device compatible, web-based cognitive assessment - and AD-related imaging biomarkers. PARTICIPANTS/SETTING: 684 adults from the Mayo Clinic Study of Aging and Mayo Clinic Alzheimer's Disease Research Center participated (age=70.4±11.2, 49.7% female). Participants were predominantly cognitively unimpaired (CU; 94.0%). MEASUREMENTS: Participants completed (1) brain amyloid and tau PET scans and MRI scans for hippocampal volume (HV) and white matter hyperintensities (WMH); (2) MTD remotely, consisting of the Stricker Learning Span and Symbols Test which combine into an MTD composite; and (3) in-person neuropsychological assessment including measures to obtain Mayo Preclinical Alzheimer's disease Cognitive Composite (Mayo-PACC) and Global-z. Multiple regressions adjusted for age, sex, and education queried associations between imaging biomarkers and scores from remote and in-person cognitive measures. RESULTS: Lower performances on MTD were associated with greater amyloid, entorhinal tau, and global tau PET burden, lower HV, and higher WMH. Mayo-PACC and Global-z were associated with all imaging biomarkers except global tau PET burden. MCI/Dementia participants showed lower performance on all MTD measures compared to CU with large effect sizes (Hedge's g's=1.65-2.02), with similar findings for CU versus MCI only (Hedge's g's=1.46-1.83). CONCLUSION: MTD is associated with continuous measures of AD-related imaging biomarkers, demonstrating ability to detect subtle cognitive change using a brief, remote assessment in predominantly CU individuals and criterion validity for MTD.

Do systolic BP and pulse pressure relate to ventricular enlargement?

BACKGROUND AND PURPOSE: To evaluate the association between systolic, diastolic and pulse pressure, and increase in ventricular size (VS). Observations in laboratory animals suggest intraventricular pulse pressure (systolic-diastolic) may play a role in ventricular enlargement. METHODS: Initial magnetic resonance (MR) scans and vascular risk factors evaluation were performed in 1812 Atherosclerosis Risk in Communities participants in 1994-1995. In 2004-2006, 1130 participants underwent repeat MR. VS was rated using a validated nine-point scale. Multiple logistic regression analysis assessed association between blood pressure measures and pulse pressure, and the change between the MR scans of VS controlling for age, sex and race. RESULTS: At baseline 1112 participants (385 black women, 200 black men, 304 white women and 223 white men) had a mean age of 61.7 ± 4.3 years. In adjusted models pulse pressure at baseline was associated with an increase in VS [odds ratio (OR) 1.19, 95% confidence interval (CI) 1.01-1.40], as was systolic pressure (OR 1.28, 95% CI 1.03-1.58). CONCLUSIONS: Systolic pressure and pulse pressure are associated with future development of increased VS. The findings are consistent with the animal literature that increased pulse pressure predisposes to risk of future increased VS. High pulse pressure might play a role in the pathogenesis of normal pressure hydrocephalus.

Voxel-based morphometry in patients with obsessive-compulsive behaviors in behavioral variant frontotemporal dementia.

BACKGROUND AND PURPOSE: Obsessions and compulsive (OC) behaviors are a frequent feature of behavioral variant frontotemporal dementia (bvFTD), but their structural correlates have not been definitively established. METHODS: Patients with bvFTD presenting to the Mayo Clinic Alzheimer's Disease Research Center were recruited. Each patient's caregiver was given the Yale-Brown Obsessive-Compulsive scale (YBOCS) to document the type and presence of OC behaviors and to rate their severity. All subjects underwent standardized magnetic resonance imaging (MRI) that was evaluated using voxel-based morphometry (VBM). Seventeen patients with bvFTD were recruited, and 11 were included in the study and compared with 11 age- and gender-matched controls. Six were excluded for lack of MRI at the time of survey or a pre-existing neurodegenerative condition. RESULTS: Nine of the 11 reported OC behaviors, with the most frequent compulsions being checking, hoarding, ordering/arranging, repeating rituals, and cleaning. In the VBM analysis, total YBOCS score correlated with gray matter loss in the bilateral globus pallidus, left putamen, and in the lateral temporal lobe, particularly the left middle and inferior temporal gyri (P < 0.001 uncorrected for multiple comparisons). CONCLUSIONS: Obsessive-compulsive behaviors were frequent among these patients. The correlation with basal ganglia atrophy may point to involvement of frontal subcortical neuronal networks. Left lateral temporal lobe volume loss probably reflects the number of MAPT mutation patients included but also provides additional data implicating temporal lobe involvement in OC behaviors.

Association of lung function with cognitive decline and dementia: the Atherosclerosis Risk in Communities (ARIC) Study.

BACKGROUND: Previous studies reported a higher risk of cognitive decline and dementia amongst individuals with impaired lung function. However, many did not adjust for important confounders or did not include women and non-whites. METHODS: We studied 10,975 men and women aged 47-70 years (23% African-Americans) enrolled in the Atherosclerosis Risk in Communities Study. Pulmonary function tests and a cognitive assessment, including the Delayed Word Recall, the Digit Symbol Substitution, and the World Fluency Tests, were carried out in 1990-1992. Repeated cognitive assessments were performed in 1996-1998 for the entire cohort, and in 1993-1995, and 2004-2006 in 904 eligible individuals. Dementia hospitalization was ascertained through 2005. RESULTS: In analysis adjusted for lifestyles, APOE genotype, and cardiovascular risk factors, impaired lung function was associated with worse cognitive function at baseline. No association was found between lung function and cognitive decline over time. Impaired lung function at baseline was associated with higher risk of dementia hospitalization during follow-up, particularly amongst younger individuals. The hazard ratios (95% confidence intervals) of dementia hospitalization were 1.6 (0.9, 2.8) and 2.1 (1.2, 3.7) comparing the lowest with the highest quartile of forced expiratory volume in 1 s and forced vital capacity, respectively. Presence of a restrictive ventilatory pattern, but not of an obstructive pattern, was associated with reduced cognitive scores and higher dementia risk. CONCLUSION: Reduced lung function was associated with worse performance in cognitive assessments and with an increased risk of dementia hospitalization. Future research should determine whether maintaining optimal pulmonary health might prevent cognitive impairment and dementia.

Longitudinal Comparison of in Clinic and at Home Administration of the Cogstate Brief Battery and Demonstrated Practice Effects in the Mayo Clinic Study of Aging.

BACKGROUND: The Cogstate Brief Battery (CBB) is a computerized cognitive assessment that can be completed in clinic or at home. Design/Objective: This retrospective study investigated whether practice effects / performance trajectories of the CBB differ by location of administration. PARTICIPANTS/SETTING: Participants included 1439 cognitively unimpaired individuals age 50-75 at baseline participating in the Mayo Clinic Study of Aging (MCSA), a population-based study of cognitive aging. Sixty three percent of participants completed the CBB in clinic only and 37% completed CBB both in clinic and at home. MEASUREMENTS: The CBB consists of four subtests: Detection, Identification, One Card Learning, and One Back. Linear mixed effects models were used to evaluate performance trajectories in clinic and at home. RESULTS: Results demonstrated significant practice effects between sessions 1 to 2 for most CBB measures. Practice effects continued over subsequent testing sessions, to a lesser degree. Average practice effects/trajectories were similar for each location (home vs. clinic). One Card Learning and One Back accuracy performances were lower at home than in clinic, and this difference was large in magnitude for One Card Learning accuracy. Participants performed faster at home on Detection reaction time, although this difference was small in magnitude. CONCLUSIONS: Results suggest the location where the CBB is completed has an important impact on performance, particularly for One Card Learning accuracy, and there are practice effects across repeated sessions that are similar regardless of where testing is completed.

Recommendations for the Nomenclature of Cognitive Change Associated with Anaesthesia and Surgery-20181.

Cognitive change affecting patients after anaesthesia and surgery has been recognised for more than 100 yr. Research into cognitive change after anaesthesia and surgery accelerated in the 1980s when multiple studies utilised detailed neuropsychological testing for assessment of cognitive change after cardiac surgery. This body of work consistently documented decline in cognitive function in elderly patients after anaesthesia and surgery, and cognitive changes have been identified up to 7.5 yr afterwards. Importantly, other studies have identified that the incidence of cognitive change is similar after non-cardiac surgery. Other than the inclusion of non-surgical control groups to calculate postoperative cognitive dysfunction, research into these cognitive changes in the perioperative period has been undertaken in isolation from cognitive studies in the general population. The aim of this work is to develop similar terminology to that used in cognitive classifications of the general population for use in investigations of cognitive changes after anaesthesia and surgery. A multispecialty working group followed a modified Delphi procedure with no prespecified number of rounds comprised of three face-to-face meetings followed by online editing of draft versions.Two major classification guidelines [Diagnostic and Statistical Manual for Mental Disorders, fifth edition (DSM-5) and National Institute for Aging and the Alzheimer Association (NIA-AA)] are used outside of anaesthesia and surgery, and may be useful for inclusion of biomarkers in research. For clinical purposes, it is recommended to use the DSM-5 nomenclature. The working group recommends that 'perioperative neurocognitive disorders' be used as an overarching term for cognitive impairment identified in the preoperative or postoperative period. This includes cognitive decline diagnosed before operation (described as neurocognitive disorder); any form of acute event (postoperative delirium) and cognitive decline diagnosed up to 30 days after the procedure (delayed neurocognitive recovery) and up to 12 months (postoperative neurocognitive disorder).

[18F] AV-1451 uptake in corticobasal syndrome: the influence of beta-amyloid and clinical presentation.

Corticobasal syndrome (CBS) is a phenotypic manifestation of diverse pathologies, including Alzheimer's disease and 4-repeat tauopathies. Predicting pathology in CBS is unreliable and, hence, molecular neuroimaging may prove to be useful. The aim of this study was to assess regional patterns of uptake on [18F] AV-1451 PET in CBS and determine whether patterns of uptake differ according to beta-amyloid deposition or differing clinical presentations. Fourteen patients meeting criteria for CBS underwent Pittsburgh Compound B (PiB) and [18F] AV-1451 PET. Seven patients presented as CBS and seven presented with apraxia of speech (AOS) and later evolved into CBS. A global PiB summary was calculated and used to classify patients as PiB (-) or PiB (+). AV-1451 uptake was calculated in fourteen regions-of-interest, with values divided by uptake in cerebellar crus grey matter to generate standard uptake value ratios. AV-1451 uptake was considered elevated if it fell above the 95th percentile from a group of 476 cognitively unimpaired normal controls. Six of the 14 CBS patients (43%) were PiB (+), with three of these patients showing strikingly elevated AV-1451 uptake across many cortical regions. Of the eight PiB (-) patients, only those with AOS showed elevated AV-1451 uptake in supplementary motor area and precentral cortex compared to controls. No region of elevated AV-1451 uptake were observed in PiB (-) typical CBS patients without AOS. These results suggest that regional [18F] AV-1451 is variable in CBS and depends on the presence of beta-amyloid as well as clinical presentation such as AOS. PiB (+) CBS does not necessarily reflect underlying Alzheimer's disease; however, the possibility some of these patients will evolve into Alzheimer's disease over time cannot be excluded.

Vascular dementia: clinical, neuroradiologic and neuropathologic aspects.

Vascular dementia (VaD) is the second most common form of dementia after Alzheimer's disease (AD), and some studies suggest that the frequency increases exponentially over the age of 65 years. This review brings attention to the current challenges in the clinical and pathologic diagnoses of vascular dementia, provides an overview of diagnostic schemes in the clinical setting, and discusses the post-mortem pathology associated with VaD. While memory impairment is essential for diagnosis of AD, the clinical syndrome in VaD is often characterized by executive dysfunction rather than memory impairment. Nevertheless, the cognitive symptoms of VaD are so pleomorphic that no single cognitive syndrome captures the range of symptomology. Additionally, there are no widely accepted neuropathologic criteria for VaD. Imaging studies provide information about the distribution and volume of lesions and provide supportive information that differentiates VaD from AD, but are complicated by the concept of ''silent infarcts''. The heterogeneity of cerebrovascular disease and the wide range of pathologic lesions suggest that classification of VaD should include specific subtypes. The main challenge in clinicopathologic correlative studies is the lack of a gold standard for pathologic diagnosis of VaD that includes thresholds for number, size and location of infarcts and ischemic injury to white matter and strategic sites such as the thalamus and hippocampus. VaD is an entity that provides many challenges to the clinician, neuroradiologist and neuropathologist in part because evidence-based studies often lack clear definitions of the disease.

Metabolomics and cognition in African American adults in midlife: the atherosclerosis risk in communities study.

Clinical studies have shown alterations in metabolic profiles when patients with mild cognitive impairment and Alzheimer's disease dementia were compared to cognitively normal subjects. Associations between 204 serum metabolites measured at baseline (1987-1989) and cognitive change were investigated in 1035 middle-aged community-dwelling African American participants in the biracial Atherosclerosis Risk in Communities (ARIC) Study. Cognition was evaluated using the Delayed Word Recall Test (DWRT; verbal memory), the Digit Symbol Substitution Test (DSST; processing speed) and the Word Fluency Test (WFT; verbal fluency) at visits 2 (1990-1992) and 4 (1996-1998). In addition, Cox regression was used to analyze the metabolites as predictors of incident hospitalized dementia between baseline and 2011. There were 141 cases among 1534 participants over a median 17.1-year follow-up period. After adjustment for established risk factors, one standard deviation increase in N-acetyl-1-methylhistidine was significantly associated with greater 6-year change in DWRT scores (ß=-0.66 words; P=3.65 × 10-4). Two metabolites (one unnamed and a long-chain omega-6 polyunsaturated fatty acid found in vegetable oils (docosapentaenoate (DPA, 22:5 n-6)) were significantly associated with less decline on the DSST (DPA: ß=1.25 digit-symbol pairs, P=9.47 × 10-5). Two unnamed compounds and three sex steroid hormones were associated with an increased risk of dementia (all P<3.9 × 10-4). The association of 4-androstene-3beta, 17beta-diol disulfate 1 with dementia was replicated in European Americans. These results demonstrate that screening the metabolome in midlife can detect biologically plausible biomarkers that may improve risk stratification for cognitive impairment at older ages.

Neuropathology of cognitively normal elderly.

Despite general agreement about the boundaries of Alzheimer disease (AD), establishing a maximum limit for Alzheimer-type pathology in cognitively intact individuals might aid in defining more precisely the point at which Alzheimer pathology becomes clinically relevant. In this study, we examined the neuropathological changes in the brains of 39 longitudinally followed. cognitively normal elderly individuals (24 women, 15 men; age range 74-95, median 85 years). Neuropathological changes of the Alzheimer type were quantified by determining neurofibrillary tangle (NFT) staging by the method of Braak and Braak and by quantification of the abundance of diffuse, cored, and neuritic plaque burden using the scheme developed by the Consortium to Establish a Registry for Alzheimer Disease (CERAD). Vascular, Lewy body, and argyrophilic grain pathology were also assessed. We found 34 subjects (87%) with a Braak stage