Evaluation of a summary score of cognitive performance for use in trials in perioperative and critical care

Association between Neuron-Specific Enolase, Memory Function, and Postoperative Delirium after Transfemoral Aortic Valve Replacement

INTRODUCTION

Although transfemoral aortic valve replacement (TAVR) is a safe treatment for elderly patients with severe aortic valve stenosis, postoperative microembolism has been described. In this secondary endpoint analysis of the POST-TAVR trial, we aimed to investigate whether changes in neuron-specific enolase (NSE)-a biomarker of neuronal damage-are associated with changes in memory function or postoperative delirium (POD).

MATERIALS AND METHODS

This was a prospective single-center study enrolling patients undergoing elective TAVR. Serum NSE was measured before and 24 h after TAVR. POD was diagnosed using CAM-ICU testing. Memory function was assessed before TAVR and before hospital discharge using the "Consortium to Establish a Registry for Alzheimer's Disease" (CERAD) word list and the digit span task (DST) implemented in "∆elta-App".

RESULTS

Subjects' median age was 82 years (25th to 75th percentile: 77.5-85.0), 42.6% of subjects were women. CERAD scores significantly increased from pre- to post-TAVR, with p < 0.001. POD occurred in 4.4% (6/135) of subjects at median 2 days after TAVR. After TAVR, NSE increased from a median of 1.85 ng/mL (1.30-2.53) to 2.37 ng/mL (1.69-3.07), p < 0.001. The median increase in NSE was 40.4% (13.1-138.0) in patients with POD versus 17.3% (3.3-43.4) in those without POD (p = 0.17).

CONCLUSIONS

Memory function improved after TAVR, likely due to learning effects, with no association to change in NSE. Patients with POD appear to have significantly higher postoperative levels of NSE compared to patients without POD after TAVR. This finding suggests that neuronal damage, as indicated by NSE elevation, may not significantly impair assessed memory function after TAVR.

App-based assessment of memory functions in patients after transfemoral aortic valve replacement

BACKGROUND

Transfemoral aortic valve replacement (TAVR) is the standard treatment for elderly patients with aortic valve stenosis. Although safe and well-established, there is a risk of intraprocedural hemodynamic instability and silent cerebral embolism, which can lead to a decline in neurocognitive function and dementia. In clinical practice, comprehensive cognitive testing is difficult to perform. AI-assisted digital applications may help to optimize diagnosis and monitoring.

METHODS

Neurocognitive function was assessed by validated psychometric tests using "∆elta -App", which uses artificial intelligence and computational linguistic methods for extraction and analysis. Memory function was assessed using the 'Consortium to Establish a Registry for Alzheimer's Disease' (CERAD) word list and digit span task (DST) before TAVR and before hospital discharge. The study is registered in the German Register of Clinical Trials (https://drks.de/search/de/trial/DRKS00020813).

RESULTS

From October 2020 until March 2022, 141 patients were enrolled at University Hospital Heart Centre Brandenburg. Mean age was 81 ± 6 years, 42.6% were women. Time between the pre- and post-interventional test was on average 6 ± 3 days. Memory function before TAVR was found to be below average in relation to age and educational level. The pre-post TAVR comparison showed significant improvements in the wordlist repeat, P < 0.001 and wordlist recall test of CERAD, P < 0.001. There were no changes in the digital span test.

CONCLUSIONS

Despite impaired preoperative memory function before TAVR, no global negative effect on memory function after TVAR was detected. The improvements shown in the word list test should be interpreted as usual learning effects in this task.

Impact of multimodal warming during general anaesthesia on postoperative cognitive dysfunction in elderly patients with gynaecological cancer: study protocol for a single-blinded randomised controlled trial

BACKGROUND

Cognitive impairment after anaesthesia and surgery is a recognised consequence. This often leads to poor health outcomes and increases healthcare resource utilisation and associated costs, especially in elderly people. However, thus far, there have not been any effective therapies for managing postoperative cognitive dysfunction (POCD). Furthermore, research on the association of multimodal warming with POCD and the clinical outcomes in older patients after gynaecological surgery has not been rigorous. For these reasons, our investigation aims to evaluate whether perioperative multimodal warming would reduce the incidence of POCD and improve prognosis in elderly patients with gynaecological cancer.

METHODS AND ANALYSIS

This is a single-centre, prospective, single-blinded randomised controlled trial. One hundred and fifty patients for gynaecological cancer surgery and 16 non-surgical controls aged 65 years or older will be studied in this trial. A series of neuropsychological tests will be completed to evaluate cognitive function in surgery patients before, at day 7 and 3 months after gynaecological cancer surgery. In addition, POCD and cognitive decline will be assessed using the reliable change index using the control group's results. The primary outcome is the prevalence of POCD in elderly gynaecological cancer surgery patients and association between perioperative multimodal warming and POCD.

ETHICS AND DISSEMINATION

The protocol for this prospective observational study was approved by the ethics committee of the West China Second University Hospital, Sichuan University (NO. KX215). Recruitment will commence in April 2021 and continue to April 2022. The findings of this trial will be disseminated in peer-reviewed journals and scientific meetings.

TRIAL REGISTRATION NUMBER

ChiCTR2100041663.

Low Diastolic Blood Pressure and Cognitive Decline in Korean Elderly People: The Korean Longitudinal Study on Cognitive Aging and Dementia

OBJECTIVE

Cardiovascular diseases are representative risk factors for the onset of cognitive decline. The purpose of this study was to confirm the relationship between diastolic blood pressure and cognitive function in elderly people in Korea.

METHODS

Data from subjects who were enrolled in the prospective Korean Longitudinal Study on Cognitive Aging and Dementia were used in this study. Data from 701 subjects whose diastolic blood pressure range did not change (≤79 mm Hg or ≥80 mm Hg) over 2 years were analyzed. To analyze the differences in cognitive function between the groups at the 2-year follow-up, an analysis of covariance was performed with covariates, which were significantly different between the two groups, and the baseline cognitive function.

RESULTS

Significant differences were observed between the two groups, and the mean scores on the constructional praxis (η2=0.010) and word list recall tests (η2=0.018) in the diastolic blood pressure ≥80 mm Hg group were higher than those in the diastolic blood pressure ≤79 mm Hg group at the 2-year follow-up.

CONCLUSION

These results indicate that maintaining a DBP below 79 mm Hg presents a greater risk of cognitive decline in Korean elderly people.

Association between changes in cerebral grey matter volume and postoperative cognitive dysfunction in elderly patients: study protocol for a prospective observational cohort study

Background

Cognitive decline is frequently observed in elderly patients after major surgery. The pathophysiology of postoperative cognitive dysfunction (POCD) remains unclear. The aim of our investigation is to identify potential associations between brain volume change and POCD in elderly patients undergoing major surgery.

Methods

This is a prospective observational cohort study approved by the regional ethics board. We intend to compare specific brain volumes (hippocampus, lateral ventricle, total grey matter volume, regional cortical thickness) on magnetic resonance imaging and cognitive functions determined by a neuropsychological assessment battery in 70 study participants aged ≥65 years before and 3 and 12 months after major noncardiac surgery. Thirty volunteers will be included as matched nonsurgical controls. The primary endpoint of the study is the change in hippocampal volume over time in patients with and without POCD. The secondary endpoint is the correlation between the change in cerebral volume and cognitive function. We will follow the STROBE guidelines for reporting the results of observational studies.

Discussion

We hypothesize that surgery under general anesthesia is associated with a loss of cerebral grey matter, and that the degree of postoperative cognitive dysfunction correlates with the extent of atrophy in areas of the brain that are relevant for cognitive functions. The validation of reproducible anatomical biomarkers, such as the specific brain volumes examined in our cohort, may serve to evaluate the effect of preventive strategies and treatment interventions for POCD in follow-up studies.

Trial registration

Clinicaltrials.gov NCT02045004. Registered 22 January 2014. Kofam.ch SNCTP000001751. Registered 21 April 2016 (retrospectively registered).

Assessing the discriminant ability, reliability, and comparability of multiple short forms of the Boston Naming Test in an Alzheimer's disease center cohort

BACKGROUND

The Boston Naming Test (BNT) is a commonly used neuropsychological test of confrontation naming that aids in determining the presence and severity of dysnomia. Many short versions of the original 60-item test have been developed and are routinely administered in clinical/research settings. Because of the common need to translate similar measures within and across studies, it is important to evaluate the operating characteristics and agreement of different BNT versions.

METHODS

We analyzed longitudinal data of research volunteers (n = 681) from the University of Kentucky Alzheimer's Disease Center longitudinal cohort.

CONCLUSIONS

With the notable exception of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) 15-item BNT, short forms were internally consistent and highly correlated with the full version; these measures varied by diagnosis and generally improved from normal to mild cognitive impairment (MCI) to dementia. All short forms retained the ability to discriminate between normal subjects and those with dementia. The ability to discriminate between normal and MCI subjects was less strong for the short forms than the full BNT, but they exhibited similar patterns. These results have important implications for researchers designing longitudinal studies, who must consider that the statistical properties of even closely related test forms may be quite different.

CERAD practice effects and attrition bias in a dementia prevention trial

BACKGROUND

The Consortium to Establish a Registry for Alzheimer's Disease (CERAD) set of tests is frequently used for tracking cognition longitudinally in both clinical and research settings. Repeated cognitive assessments are an important component in measuring such changes; however, practice effects and attrition bias may obscure significant clinical change over time. The current study sought to examine the presence and magnitude of practice effects and the role of attrition bias in a sample of cognitively normal older men enrolled in a prevention trial.

METHOD

Participants were grouped according to whether they completed five years of follow-up (n = 182) or less (n = 126). Practice effects were examined in these participants as a whole (n = 308) and by group.

RESULTS

Findings indicate that moderate practice effects exist in both groups on the CERAD T-score and that attrition bias likely does not play a contributing role in improved scores over time.

CONCLUSION

The current study provides additional evidence and support for previous findings that repeated cognitive assessment results in rising test scores in longitudinally collected data and demonstrates that these findings are unlikely to be due to attrition.

Can postoperative cognitive dysfunction be avoided?

Postoperative cognitive dysfunction (POCD) refers to a postoperative decline in cognitive function compared with preoperative cognitive function. Diagnosis requires pre- and postoperative testing, the latter of which is usually performed both 7 days and 3 months postoperatively. Although several risk factors for POCD have been described, age is the only consistently reported risk factor. Postoperative cognitive dysfunction is often transient. It may last several months, and is associated with leaving the labor market prematurely and increased mortality. As the pathophysiology of POCD is still a matter of debate and is likely to be multifactorial, there are no widely accepted prophylactic and therapeutic interventions. In this article, we discuss POCD's definition, risk factors, long-term significance, and pathophysiology. We also present data on prophylactic interventions that have been investigated in clinical trials.

Within-session practice effects in patients referred for suspected dementia

BACKGROUND

Practice effects are improvements in cognitive test performance associated with repeated administrations of same or similar measures and are traditionally seen as error variance. However, there is growing evidence that practice effects provide clinically useful information.

METHODS

Within-session practice effects (WISPE) across 2 h were collected from 61 non-consecutive patients referred for suspected dementia and compared to the Mini Mental Status Examination (MMSE), a screening measure of dementia severity.

RESULTS

In all patients, WISPE on two cognitive measures were significantly correlated with MMSE, even after controlling for baseline cognitive scores (partial r = 0.47, p < 0.001; partial r = 0.26, p = 0.046). In patients diagnosed with probable Alzheimer's disease, the trend was even stronger (partial r = 0.72, p < 0.01; partial r = 0.58, p = 0.046). In both groups, lower WISPE were associated with lower MMSE scores (i.e. greater dementia severity), even after controlling for initial cognitive scores.

CONCLUSION

If future research validates these findings with longitudinal studies, then WISPE may have important clinical applications in dementia evaluations.