Detection of cognitive decline after coronary surgery: a comparison of computerized and conventional tests

A review of methods for assessment of cognitive function in high-altitude hypoxic environments

Hypoxic environments like those present at high altitudes may negatively affect brain function. Varying levels of hypoxia, whether acute or chronic, are previously shown to impair cognitive function in humans. Assessment and prevention of such cognitive impairment require detection of cognitive changes and impairment using specific cognitive function assessment tools. This paper summarizes the findings of previous research, outlines the methods for cognitive function assessment used at a high altitude, elaborates the need to develop standardized and systematic cognitive function assessment tools for high-altitude hypoxia environments.

Comparing analog and digital neurocognitive tests with older adults: a study of the ISPOCD battery vs. a digital test battery from Mindmore

BACKGROUND

Delayed neurocognitive recovery and neurocognitive disorder are common postoperative complications among older adults. The assessment of these complications traditionally relies on analog neurocognitive tests, predominantly using the test battery from the ISPOCD-study as the standard approach. However, analog tests are time-consuming and necessitate trained staff which poses limitations. The potential availability of a digital neurocognitive test as an alternative to the ISPOCD remains unknown. We conducted a comparative study between the analog test battery from ISPOCD and the self-administrated digital test battery developed by Mindmore.

METHODS

We conducted a crossover study with 50 cognitively healthy older adults ≥ 60 years of age recruited in Stockholm Sweden, between February and April 2022. The primary outcome focused on measuring comparability between the two test batteries. Our secondary outcomes included assessing participants' perceptions and attitudes about the tests with qualitative interviews and their usability experiences.

RESULTS

Fifty older adults, mean age 76, female 56%, with a university or college degree 48% participated in the study. The sub tests in two test batteries demonstrated a medium-large correlation (r = 0.3-0.5), except for one measure. For four out of six measures, significant differences were found with medium to large effect sizes, ranging from 0.57-1.43. Two categories were recognized in the qualitative analysis: self-competing in a safe environment, and experience with technology. Participants expressed feeling safe and at ease during the assessment, with some preferring the digital test over the analog. Participants reported a high level of usability with the digital test and a majority participants (n = 47) reported they would undergo the digital test for a potential future surgery.

CONCLUSIONS

The digital test battery developed by Mindmore offers several advantages, including rapid access to test results, easy comprehension, and use for participants, thereby increased accessibility of cognitive screening.

TRIAL REGISTRATION NUMBER

NCT05253612; ClinicalTrials.gov, 24/02/2022.

Cognitive function following surgery for pelvic organ prolapse

INTRODUCTION AND HYPOTHESIS

Older women are at higher risk for cognitive dysfunction following surgery. We hypothesized that for women undergoing pelvic organ prolapse (POP) surgery, memory function would not be significantly different at delayed postoperative assessment compared to baseline.

OBJECTIVE

We sought to compare performance on tests of various neurocognitive domains before and after surgery for POP.

METHODS

A prospective cohort study was conducted with women, aged 60 years and older who were undergoing surgery for POP. A battery of highly sensitive neurocognitive tests was administered preoperatively (baseline), on postoperative day 1 (postoperative visit 1, POV1), and at the first postoperative clinic visit 4-6 weeks after surgery (postoperative visit 2, POV2). The test battery included the scene-encoding memory task, the n-back task, the Iowa gambling task, the balloon analogue risk task, and the psychomotor vigilance task. These tests assessed the neurocognitive subdomains of episodic memory, working memory, decision-making, risk-taking, and sustained attention. Two score comparisons were made: between baseline and POV1, and between baseline and POV2.

RESULTS

In 29 women, performance on the scene-encoding memory task was worse at POV1 than at baseline (2.22 ± 0.4 vs. 2.45 ± 0.6, p < 0.05) but was better than baseline at POV2 (2.7 ± 0.7 vs. 2.45 ± 0.6, p < 0.05). Similarly, performance on the psychomotor vigilance test was worse at POV1 than at baseline (p < 0.01) but there was no difference at POV2. There was no difference in performance on the Iowa gambling test, n-back test, and balloon analogue risk tasks between baseline and any postoperative visit.

CONCLUSION

Cognitive test scores did not worsen significantly between baseline and delayed postoperative assessments in older women undergoing surgery for POP.

Is the analogue cognitive test from the ISPOCD equivalent to the digital cognitive test Mindmore? A protocol for a randomised cross-over study including qualitative interviews with self-reported healthy seniors

INTRODUCTION

Postoperative cognitive decline affects cognitive domains such as executive functions, memory, concentration and information processing. The analogue neuropsychological test developed by the International Study Group of Postoperative Cognitive Dysfunction (ISPOCD) is a well-established test for assessing cognitive performance. However, analogue tests are time-consuming, rarely cost-effective and can be at risk of administration bias. Digital solutions are comparable to analogue ones, have higher degrees of compliance and enable more standardised execution than analogue tests. Currently, there is a lack of recommendations for clinical evaluation of the patient's cognition in the perioperative setting, standard care usually means no cognitive assessments prior or after the surgery. There is a need to find an equivalent neuropsychological test to the ISPOCD to make it accessible and easier to implement in a clinical context for perioperative patients. This study aims to examine how healthy seniors perform on two neuropsychological tests, analogue versus digital and measure equivalency between tests with correlation analysis.

METHODS AND ANALYSIS

This study will use a randomised cross-over design, including qualitative interviews regarding test experiences. Healthy participants ≥60 years of age will be eligible to participate in the study. Cognitive function will be measured by using the ISPOCD test and the Mindmore digital test. The participants will self-report depressive symptoms with the Geriatric Depression Scale-15, user experience of the digital test using a modified version of the System Usability Scale and answer questionnaires targeting their experiences after the tests. Furthermore, according to the Swedish Quality of Recovery Scale, self-reported concentration difficulties will also be measured.

ETHICS AND DISSEMINATION

The study has been approved by the Swedish Ethical Review Authority (Dnr 2021-05486-01) and will follow the principles outlined in the 1964 Helsinki Declaration and its later amendments. Results from this study will be disseminated in peer-reviewed journals, at scientific conferences, and in social media.

TRIAL REGISTRATION NUMBER

2021-01095; ClinicalTrials.gov.

Cognitive decline among older adults: A hidden preexisting condition and its role in 'brain-at-risk' surgical patients

Preexisting cognitive impairment is an important, but underrecognized, predictor of postoperative neurocognitive dysfunction, a common and important sequela of surgery. We have applied computerized neuropsychological testing as an efficient and reliable means of detecting preexisting cognitive impairment in two studies of cardiac and noncardiac surgical populations and propose that this tool has great potential in routine clinical diagnosis.

Cognitive Outcomes after DEXmedetomidine sedation in cardiac surgery: CODEX randomised controlled trial protocol

INTRODUCTION

Older patients undergoing cardiac surgery carry the highest risk for developing major postoperative neurocognitive disorder (postoperative NCD or P-NCD) with up to 25% incidence 3 months after surgery. P-NCD is associated with significant morbidity, mortality, loss of independence, premature retirement and increased healthcare costs. This multicentre randomised trial is investigating the efficacy of postoperative dexmedetomidine sedation in reducing the incidence of major P-NCD after cardiac surgery compared with standard protocols. CODEX will be the largest interventional trial with major P-NCD as the primary outcome.

METHODS AND ANALYSIS

CODEX is recruiting patients ≥60 years old, undergoing elective cardiac surgery and without pre-existing major cognitive dysfunction or dementia. Eligible participants are randomised to receive postoperative dexmedetomidine or standard institutional sedation protocols in the intensive care unit. Baseline preoperative cognitive function is assessed with the computer-based Cogstate Brief Battery. The primary outcome, major P-NCD, 3 months after surgery is defined as a decrease in cognitive function ≥1.96 SD below age-matched, non-operative controls. Secondary outcomes include delirium, major P-NCD at 6/12 months, depressive symptoms, mild P-NCD and quality of surgical recovery at 3/6/12 months. The specific diagnostic criteria used in this protocol are consistent with the recommendations for clinical assessment and management of NCD from the Nomenclature Consensus Working Group on perioperative cognitive changes. Intention-to-treat analysis will compare major P-NCD at 3 months between study groups.

ETHICS AND DISSEMINATION

CODEX was approved by Sunnybrook Health Sciences Centre Research Ethics Board (REB) (Project ID 1743). This will be the first multicentre, randomised controlled trial to assess the efficacy of a pharmacological intervention to reduce the incidence of major P-NCD after cardiac surgery in patients ≥60 years old. Dissemination of the study results will include briefings of key findings and interpretation, conference presentations and peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT04289142.

Cognitive impairment and psychological state in acute coronary syndrome patients: A prospective descriptive study at cardiac rehabilitation entry, completion and follow-up

BACKGROUND

Cognitive impairment may limit the uptake of secondary prevention in acute coronary syndrome patients, but is poorly understood, including in cardiac rehabilitation participants.

AIM

The aim of this study was to explore cognitive impairment in relation to psychological state in acute coronary syndrome patients over the course of cardiac rehabilitation and follow-up.

METHODS

Acute coronary syndrome patients without diagnosed dementia were assessed on verbal learning, processing speed, executive function and visual attention, at cardiac rehabilitation entry, completion and follow-up and scores adjusted using normative data. The hospital anxiety and depression scale measured psychological state.

RESULTS

Participants (n = 40) had an average age of 66.2 (±8.22) years and were 70% men. Mild cognitive impairment occurred at cardiac rehabilitation entry in single 62.5% and multiple 22.5% domains but was significantly less prevalent by cardiac rehabilitation completion (52.5% and 15.0%) and follow-up (32.5% and 7.0%). Domains most often impaired were verbal learning (52.5%) and processing speed (25.6%), again decreasing significantly with time (verbal learning cardiac rehabilitation completion 42.5%, follow-up 22.5%; processing speed cardiac rehabilitation completion 15.0%, follow-up 15.0%). A small group of patients had persistent multiple domain cognitive impairment. At cardiac rehabilitation entry patients with cognitive impairment in processing speed, a single domain or multiple domains had more depression, and patients with cognitive impairment in executive function had more depression and anxiety.

CONCLUSIONS

At cardiac rehabilitation entry, mild cognitive impairment is very common in post-acute coronary syndrome patients and worse in patients who have depression or anxiety symptoms. Cognitive impairment decreases significantly by cardiac rehabilitation follow-up. A small proportion of patients has persistent, multiple domain cognitive impairment flagging potential long-term changes and the need for further investigations and cognitive rehabilitation.

The effects of surgery on plasma vitamin C concentrations and cognitive function: a protocol for a prospective, observational study

BACKGROUND

Post-operative cognitive function has recently become an area of focus for researchers. The most commonly reported perioperative neurocognitive disorders include delirium and longer-lasting post-operative cognitive dysfunctions. The contributing pathophysiology to these complications remains unclear. A number of studies have systematically revealed a significant post-operative plasma vitamin C depletion. Recent insights have also exhibited a link between plasma vitamin C and numerous biological roles in brain function, with deficiencies potentially compromising cognitive function.

AIM

The present prospective, observational study will investigate whether there is a possible link between post-operative plasma vitamin C depletion and cognitive dysfunction.

METHODS

The cohort will consist of surgical patients, between the ages of 65 and 85 years, undergoing hip replacement surgery or a control group not exposed to surgical trauma. Participants will have their plasma vitamin C concentrations tested alongside a battery of computer-based cognitive assessments and paper and pen based cognitive tests. Further assessments will include dietary nutritional intake, serum vitamin B12 concentrations, cardiovascular biomarkers, wound healing, sleep quality, pain, mood and inflammatory cytokines. Participants will be tested at baseline (1-2 weeks prior to surgery) and subsequent testing sessions will be performed within 1 week, 4-6 weeks, 3 months and 6 months following surgery.

CONCLUSIONS

Findings from this observational study will provide insight into whether there is a concomitant depletion in post-operative plasma vitamin C concentrations and cognition function. Extrapolated results may prompt future, extensive randomized controlled trials to assess whether vitamin C supplementation can alleviate or even prevent post-operative cognitive complications.

Protocol for a prospective cohort study of assessing postoperative cognitive changes after total hip and knee arthroplasty in the Greater Toronto area

INTRODUCTION

Cognitive changes after anaesthesia and surgery, such as delirium and postoperative cognitive dysfunction (POCD), are common and lead to poor outcomes and increased healthcare costs. While several interventions for delirium exist, there are no effective treatment strategies for POCD. Understanding the risks and contributing factors may offer clinicians unique opportunities to better identify and develop preventative interventions for those at higher risk. Elderly patients undergoing orthopaedic surgery are at high risk of developing postoperative delirium (PD) and POCD. The incidence of POCD has not been rigorously studied in the total hip and knee arthroplasty (THA/TKA) population. Therefore, we have designed a prospective, observational cohort study to assess POCD in patients undergoing THA/TKA, both increasingly common procedures. The incidence of PD and POCD in a high volume, tertiary care arthroplasty centre will be determined and associated risk factors will be identified.

METHODS AND ANALYSIS

Cognitive function will be tested with a computer-based cognitive assessment tool [CogState Brief Battery], preoperatively at baseline and postoperatively while in hospital at (<3 days), 6 weeks and 4.5 months. The primary outcome is the incidence of postoperative cognitive decline at 4.5 months. Logistic regression analysis is planned to test the association of POCD with several potential risk factors. In addition, delirium will be assessed preoperatively and postoperatively in the hospital using the Confusion Assessment Method (3D-CAM).

ETHICS AND DISSEMINATION

The protocol for this prospective observational study was approved by the Sunnybrook Health Sciences Centre Research Ethics Board (REB#: 040-2017). Recruitment commenced in May 2017 and will continue until 2019. The results will be disseminated in a peer-reviewed journal and in scientific meetings.

TRIAL REGISTRATION NUMBER

NCT03147937.

Monitoring cognitive change in multiple sclerosis using a computerized cognitive battery

Background

Cognitive monitoring that can detect short-term change in multiple sclerosis is challenging. Computerized cognitive batteries such as the CogState Brief Battery can rapidly assess commonly affected cognitive domains.

Objectives

The purpose of this study was to establish the acceptability and sensitivity of the CogState Brief Battery in multiple sclerosis patients compared to controls. We compared the sensitivity of the CogState Brief Battery to that of the Paced Auditory Serial Addition Test over 12 months.

Methods

Demographics, Expanded Disability Status Scale scores, depression and anxiety scores were compared with CogState Brief Battery and Paced Auditory Serial Addition Test performances of 51 patients with relapsing-remitting multiple sclerosis, 19 with secondary progressive multiple sclerosis and 40 healthy controls. Longitudinal data in 37 relapsing-remitting multiple sclerosis patients were evaluated using linear mixed models.

Results

Both the CogState Brief Battery and the Paced Auditory Serial Addition Test discriminated between multiple sclerosis and healthy controls at baseline (p<0.001). CogState Brief Battery tasks were more acceptable and caused less anxiety than the Paced Auditory Serial Addition Test (p<0.001). In relapsing-remitting multiple sclerosis patients, reaction time slowed over 12 months (p<0.001) for the CogState Brief Battery Detection (mean change -34.23 ms) and Identification (-25.31 ms) tasks. Paced Auditory Serial Addition Test scores did not change over this time.

Conclusions

The CogState Brief Battery is highly acceptable and better able to detect cognitive change than the Paced Auditory Serial Addition Test. The CogState Brief Battery could potentially be used as a practical cognitive monitoring tool in the multiple sclerosis clinic setting.

Impaired cognitive processing speed in type 1 diabetic patients who had severe/recurrent hypoglycaemia

AIMS

To detect whether adults with type 1 diabetes mellitus (T1DM) have lower cognitive performance than healthy individuals and to detect risk factors for low cognitive performance.

METHODS

Twenty-six adults with T1DM and twenty-six healthy subjects matched for age, gender and educational level were compared for cognitive performance by a chronometric computerized test measuring visuo-spatial working memory (N-Back) and by two validated neuropsychological tests (Mini Mental State Examination, Animal Naming Test). Clinical data about diabetes duration, average daily insulin dosage, glycated haemoglobin, retinopathy, urine albumin-creatinine ratio, previous hypoglycaemic coma and awareness of hypoglycaemia were obtained from medical records. Basal pre-test glycemia and blood pressure were measured for each patient.

RESULTS

No differences were found between patients (n = 26) and healthy controls (n = 26) in neuropsychological tests. Within diabetic patients, those with impaired awareness of hypoglycaemia (n = 7) or history of coma in the recent 1-3 years (n = 5) had psychomotor slowing at the N-Back test (592 ± 35 vs. 452 ± 21 ms and 619 ± 40 vs. 462 ± 19 ms, respectively; both p < 0.01). The variables related to diabetic severity did not show a relationship with reaction times of the N-Back test.

CONCLUSION

Psychomotor speed slowing is detectable in patients with T1DM who have a history of previous hypoglycaemic episodes or coma.

Assessing the feasibility of using the Dalhousie Computerized Attention Battery to measure postoperative cognitive dysfunction in older patients

Purpose

Postoperative cognitive dysfunction is difficult to predict and diagnose, and can have severe consequences in the long term. The purpose of this study was to examine the feasibility of using a computerised test battery, the Dalhousie Computerized Assessment Battery in the perioperative clinic to detect cognitive changes after surgery.

Methods

Fifty patients were recruited for this study. Patients completed the Dalhousie Computerized Assessment Battery and tests of general cognition, mood and pain at baseline and at three months postoperatively.

Results

This pilot study had a screening rate (85.4%) and low attrition rate (12%). At baseline, patients exhibited no significant cognitive differences compared to a normative dataset. Postoperative cognitive dysfunction incidence was 2.7% on Montreal Cognitive Assessment, 13.6% with Dalhousie Computerized Assessment Battery and 36.3% based on subjective reports.

Conclusion

Computerised cognitive testing in the perioperative setting proved feasible. Deficits in spatial working memory and dual tasks may be most compromised by surgically related variables.

Cognitive Function Before and After Left Heart Catheterization

BACKGROUND

Hospital procedures have been associated with cognitive change in older patients. This study aimed to document the prevalence of mild cognitive impairment in individuals undergoing left heart catheterization (LHC) before the procedure and the incidence of cognitive decline to 3 months afterwards.

METHODS AND RESULTS

We conducted a prospective, observational, clinical investigation of elderly participants undergoing elective LHC. Cognition was assessed using a battery of written tests and a computerized cognitive battery before the LHC and then at 3 months afterwards. The computerized tests were also administered at 24 hours (or discharge) and 7 days after LHC. A control group of 51 community participants was recruited to calculate cognitive decline using the Reliable Change Index. Of 437 participants, mild cognitive impairment was identified in 226 (51.7%) before the procedure. Computerized tests detected an incidence of cognitive decline of 10.0% at 24 hours and 7.5% at 7 days. At 3 months, written tests detected an incidence of cognitive decline of 13.1% and computerized tests detected an incidence of 8.5%. Cognitive decline at 3 months using written tests was associated with increasing age, whereas computerized tests showed cognitive decline was associated with baseline amnestic mild cognitive impairment, diabetes mellitus, and prior coronary stenting.

CONCLUSIONS

More than half the patients aged >60 years presenting for LHC have mild cognitive impairment. LHC is followed by cognitive decline in 8% to 13% of individuals at 3 months after the procedure. Subtle cognitive decline both before and after LHC is common and may have important clinical implications.

CLINICAL TRIAL REGISTRATION INFORMATION

URL: www.anzctr.org.au. Unique identifier: ACTRN12607000051448.

The practice of clinical neuropsychology in Australia

OBJECTIVE

This paper describes the development and practice of clinical neuropsychology in Australia.

METHOD

Clinical Neuropsychology has shown rapid growth in Australia over the past three decades. Comprehensive and specialized training programs are producing high quality graduates who are employed in a broad range of settings or private practice.

RESULTS

Australia now has a substantial number of clinical neuropsychologists with specialist training. Whilst the majority of Australian clinical neuropsychologists still undertake assessment predominantly, there are growing opportunities for clinical neuropsychologists in rehabilitation and in a broad range of research contexts. Cultural issues relating to the assessment of Indigenous Australians and immigrants from many countries present significant challenges. Some major contributions have been made in the realms of test development and validation across various age groups. Australian clinical neuropsychologists are also contributing significantly to research in the fields of traumatic brain injury, aging and dementias, epilepsy, memory assessment, rehabilitation, substance abuse, and other psychiatric disorders.

CONCLUSION

Expansion of roles of clinical neuropsychologists, in domains such as rehabilitation and research is seen as essential to underpin continuing growth of employment opportunities for the profession.

Assessment of Neurocognitive Functions in Children and Adolescents with Obesity

Obesity is linked to adverse neurocognitive outcomes including reduced cognitive functioning. We aimed to investigate the differences in neuropsychological test performance of Turkish children and adolescents with obesity and healthy peers. Study includes 147 children and adolescents ranging in age from 8 to 16 years: 92 with obesity and 55 with healthy controls. After the participants were administered the Children's Depression Inventory (CDI) and the Screen for Child Anxiety Related Disorders (SCARED), they completed the battery tests of the Central Nervous System Vital Signs (CNSVS), a neurocognitive test battery, via computer. The battery calculates seven domain scores (Memory, Psychomotor speed, Processing speed, Reaction time, Complex attention, Executive Function, Cognitive flexibility), and a summary score (Neurocognition Index [NCI]). There was a statistically significant difference between the obesity and control groups on all cognitive domains. The mean NCI score of the obesity group was 81.3 ± 10.24 compared to 97.29 ± 4.97 for the control group. The mean NCI score in the obesity group was significantly lower than that of the control group (p < 0.001). The mean scores of other domains of obese patients were also found to be significantly lower than those of the control participants (p < 0.001). The mean SCARED scores of the participants with obesity were found to be significantly higher than those of the control participants (p < 0.05). However, no statistically significant relationship was found between the SCARED and the CNSVS scores. Cognitive dysfunction in children and adolescents with obesity should be taken into consideration when assessing and managing this population.

Adjuvant ovarian function suppression and cognitive function in women with breast cancer

BACKGROUND

To examine the effect on cognitive function of adjuvant ovarian function suppression (OFS) for breast cancer.

METHODS

The Suppression of Ovarian Function (SOFT) trial randomised premenopausal women with hormone receptor-positive breast cancer to 5 years adjuvant endocrine therapy with tamoxifen+OFS, exemestane+OFS or tamoxifen alone. The Co-SOFT substudy assessed objective cognitive function and patient reported outcomes at randomisation (T0), and 1 year later (T1); the primary endpoint was change in global cognitive function, measured by the composite objective cognitive function score. Data were compared for the pooled tamoxifen+OFS and exemestane+OFS groups vs the tamoxifen alone group using the Wilcoxon rank-sum test.

RESULTS

Of 86 participants, 74 underwent both T0 and T1 cognitive testing; 54 randomised to OFS+ either tamoxifen (28) or exemestane (26) and 20 randomised to tamoxifen alone. There was no significant difference in the changes in the composite cognitive function scores between the OFS+ tamoxifen or exemestane groups and the tamoxifen group (mean±s.d., -0.21±0.92 vs -0.04±0.49, respectively, P=0.71, effect size=-0.20), regardless of prior chemotherapy status, and adjusting for baseline characteristics.

CONCLUSIONS

The Co-SOFT study, although limited by small samples size, provides no evidence that adding OFS to adjuvant oral endocrine therapy substantially affects global cognitive function.

The importance of cognition to quality of life after stroke

OBJECTIVE

Suffering a stroke typically has a negative impact on a person's quality of life. There is some evidence that post-stroke cognitive impairment is associated with poor quality of life, but the relative importance of deficits in different cognitive domains has not been established.

METHODS

Patients with confirmed stroke were recruited in the acute hospital. A subgroup of patients completed 2 computerized cognitive tasks (simple and choice reaction time) within 2 weeks of stroke. The full cohort was followed up at 3 months with a comprehensive neuropsychological battery and then at 12 months with the Assessment of Quality of Life ('AQoL).

RESULTS

Sixty patients participated in the study (mean age 72.1 years, SD 13.9), with a subgroup of 33 patients tested acutely (mean age 75.5 years, SD 11.9). Presence of cognitive impairment at 3 months was independently associated with lower quality of life at 12 months (p=0.021). Attention and visuospatial ability were the cognitive domains most closely associated with quality of life. Faster choice reaction time in the acute stage (mean 5.4 days post-stroke) was significantly associated with better quality of life at 12 months (p=0.003).

CONCLUSION

Cognition, particularly attention and visuospatial ability, is strongly associated with quality of life after stroke. It is possible that straightforward reaction time tasks are sensitive to the extent of brain damage, and might therefore be surrogate markers for quality of life.

Neurocognitive functioning in adolescents with eating disorders: a population-based study

INTRODUCTION

Neurocognitive deficits have been identified in eating disorders, including anorexia nervosa and bulimia nervosa. However, current data do not allow for firm conclusions regarding the nature or extent of these deficits. The current study aimed to evaluate neurocognitive functioning in a population-based sample of adolescents with and without eating disorders.

METHODS

Participants (N=669) were drawn from the Western Australian Pregnancy Cohort (Raine) Study. Cognitive testing was conducted using the computerised CogState assessment battery. Eating disorder symptoms were assessed using questions adapted from the Child Eating Disorder Examination and Eating Disorder Examination-Questionnaire. Adolescents who met full or partial criteria for a DSM-IV eating disorder (n=58) were compared to adolescents with no significant eating pathology (n=592).

RESULTS

The eating disorder sample showed impaired performance on measures of executive functioning, including global processing and set shifting, but performed better than control participants on measures of visual attention and vigilance.

CONCLUSIONS

This is the first study to evaluate neurocognitive functioning in a population-based sample of adolescents with eating disorders. Support is provided for weak central coherence and set-shifting difficulties early in the course of eating disorders. Research is needed to determine if these deficits precede and predict eating disorder onset.

Use of computerized tests to assess the cognitive impact of interventions in the elderly

With the aging of the population, the possibility of the occurrence of cognitive decline rises. A number of types of intervention seek to attenuate or reverse this impairment. The use of computerized tests helps quantify the effects of interventions on cognitive function in the elderly. The objective of the present review was to analyze studies that have utilized computerized cognitive tests to determine the effects of interventions in the elderly population, describing the batteries and tests employed, the populations studied and reports by authors on the limitations or benefits of employing these tests in older adults. The review was performed on the PubMed database using the descriptors: cognitive computerized test and elderly. We retrieved 530 studies and, following analysis of their abstracts, selected 32 relevant to the subject. The studies utilized 19 different types of computerized tests and batteries to assess the interventions, which were predominantly drug trials. There were no reports on limitations in the use of the computerized tests, suggesting this type of intervention had good applicability, sensitivity, and little or no practice effects in this population.

Cognitive outcomes 7.5 years after angioplasty compared with off-pump coronary bypass surgery

BACKGROUND

Off-pump coronary artery bypass grafting and percutaneous coronary intervention are both associated with cognitive decline, but limited data are available on long-term outcomes. This study compared long-term cognitive outcomes between patients managed with percutaneous coronary intervention and off-pump coronary artery bypass grafting.

METHODS

A multicenter trial in the Netherlands randomized 280 patients to percutaneous coronary intervention or off-pump coronary artery bypass grafting. Cognitive performance 7.5 years after randomization was assessed through a battery of 9 neuropsychologic tests and summarized into a combined Z-score.

RESULTS

After 7.5 years, cognitive assessment could be performed in 81% of the 249 surviving patients. Better cognitive performance was observed in the off-pump coronary artery bypass grafting group (combined Z-score 0.11 for off-pump coronary artery bypass grafting versus -0.17 for percutaneous coronary intervention; difference 0.28, 95% confidence interval 0.08 to 0.47, p < 0.01). However, this difference became nonsignificant (Z-score difference 0.14, 95% confidence interval -0.01 to 0.29, p = 0.08) after multivariable adjustment for potential confounders.

CONCLUSIONS

At 7.5 years follow-up, off-pump coronary artery bypass grafting patients had a similar or perhaps even better cognitive performance compared with percutaneous coronary intervention patients.

Clinical, methodological and theoretical issues in the assessment of cognition after anaesthesia and surgery: a review

As people live longer, the burden of cognitive impairment to elderly patients, their families and society becomes increasingly common and important. The loss of independence, a reduction in the quality of life and increased mortality are possible correlates to the mental disintegration. Cognitive dysfunction following major surgery on the elderly is a significant problem which adds to other cognitive impairments caused by neurodegeneration, cerebrovascular impairments and other causes. There are challenges in reviewing the literature because of many methodological concerns. There is no standard definition; the diagnosis is made only by the results of neuropsychological tests which are not standardised for this purpose; test results are analysed by different statistical methods (some of them inappropriate); controls are often absent or poorly matched; and pre-existing mild cognitive impairment, which affects 10 to 20% of people older than 65 years and is similar to the subtle cognitive impairment following surgery, is not sought for and recognised. Reviews of the subject have varied from descriptions such as 'a well recognised and significant problem' to 'a hypothetical phenomenon for which there is no International Statistical Classification of Disease (ICD-9) code, and no Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) code'. This article examines both sides of the spectrum in a detailed review which explains the necessary psychological 'jargon', discusses the methods used and points to areas of future research.

The Influence of Low and Moderate Carotid Stenosis on Neurophysiologic Status of Patients Undergoing on-pump Coronary Artery Bypass Grafting

BACKGROUND

Significant (>70%) extracranial stenosis of the internal carotid artery (ICA) is a known risk factor for brain damage in patients with coronary heart disease (CHD) undergoing coronary artery bypass grafting (CABG). There is no clear evidence of the low and moderate ICA stenoses influence on the neurophysiologic status of patients after CABG. This work was aimed at studying the influence ICA stenoses (<50%) on the dynamics of neurophysiologic status in patients undergone CABG.

METHODS

We examined neurophysiologic functions and electroencephalograph in CHD patients (N = 45) aged from 45 to 70 years. All patients were divided into two groups: with ICA stenosis (n = 20) and without one (n = 25).

RESULTS

It was established that the group ICA stenosis had a negative dynamics of neurophysiologic status 6 months follow-up after CABG compared with patients without stenosis.

CONCLUSION

Our results suggest that the presence of low and moderate ICA stenosis is one of the factors affecting the neurophysiologic status of CHD patients. It has been assumed that the patients with ≤50% ICA stenoses constitute a high-risk group for cerebral complications after on-pump CABG.

Use of the CogState Brief Battery in the assessment of Alzheimer's disease related cognitive impairment in the Australian Imaging, Biomarkers and Lifestyle (AIBL) study

The aim of this study was to validate the CogState Brief Battery, which assesses psychomotor, attentional, working memory, and visual learning functions, in healthy older people and in patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD), enrolled in the Australian Imaging, Biomarkers and Lifestyle (AIBL) study. In healthy older adults, weak relationships between demographic variables (e.g., education, depression) and cognitive performance were observed. In AD and MCI groups, the magnitude of impairment was greatest for tasks of working memory and memory, with a negative influence of apolipoprotein E ϵ4 status on learning but not working memory. These results suggest that the CogState Brief Battery can be used to screen for AD-related cognitive changes.

Assessment of cognitive function before and after surgery for posterior cranial fossa lesions using computerized and conventional tests

Cognitive function has not been well studied after neurosurgery for posterior fossa lesions despite its potential importance in determining surgical indications and approaches. The present study evaluated changes in cognitive functions after posterior fossa surgery to detect any differences between the middle cranial fossa and lateral suboccipital approaches in 50 patients with posterior fossa lesions such as tumors and vascular diseases. Twenty-five patients underwent surgery via the middle fossa and 25 via the lateral suboccipital approaches. Computerized test battery (CogState) and conventional neuropsychological tests (serial seven-word learning test and mini-mental state examination) were examined before, 1 month after, and 3 months after surgery. All scores of the neuropsychological tests remained within normal limits after surgery. However, the scores of one computerized test battery and serial seven-word learning tests decreased significantly 1 month after surgery and recovered within 3 months, indicating temporary deterioration of short-term memory in the middle fossa group. The computerized tests detected significantly larger numbers of patients with worsened results than the conventional tests. The middle fossa approach and operation time showed correlations with the postoperative neuropsychological declines. The computerized tests could be performed easily and were beneficial for detecting subtle changes of the cognitive function after surgery. Cognitive function, especially short-term memory, may decline temporarily with the middle fossa approach and long operation time.

Cognitive function in patients undergoing coronary angiography

OBJECTIVE

To measure cognition in patients before and after coronary angiography.

DESIGN

Prospective observational cohort study.

SETTING

University teaching hospital.

PATIENTS

56 patients presenting for elective coronary angiography.

MAIN OUTCOME MEASURES

Computerised cognitive test battery administered before coronary angiography, before discharge from hospital and 7 days after discharge. A matched healthy control group was used as a comparator.

RESULTS

When analysed by group, coronary angiography patients performed worse than matched controls at each time point. When the cognitive change was examined for each individual, of the 48 patients tested at discharge, 19 (39.6%) were classified as having a new cognitive dysfunction, and of 49 patients tested at day 7, six (12.2%) were classified as having a new cognitive dysfunction.

CONCLUSIONS

The results confirm that cognitive function is decreased in patients who have cardiovascular disease. Furthermore, coronary angiography may exacerbate this impaired cognition in some patients.

Postoperative cognitive dysfunction: computerized and conventional tests showed only moderate inter-rater reliability

PURPOSE

The incidence of postoperative cognitive dysfunction (POCD) depends on the test battery and calculation method used. The measurements may be performed with a paper and pencil test battery or with a computerized test battery. The objective of this study was to measure the incidence and congruence of POCD by comparing a computerized test battery with a paper and pencil test battery in the same patient population.

METHODS

In total, 67 patients were included: 30 consecutive in-patients undergoing surgery under general anesthesia and 37 non-surgical out-patients as control. Patients were tested with a paper and pencil test battery and a computerized test battery on inclusion in the study and 7 days later. Both test batteries covered the cognitive domains: visual attention, visual learning, memory, and speed of processing.

RESULTS

The computerized test battery classified 10.0% (95% CI 3.5-25.6%) of the patients as suffering from POCD whereas the paper and pencil test battery classified 30.0% (95% CI 16.7-47.9%) as suffering (95% CI for difference 3.9-36.5%, P = 0.03). The inter-rater reliability between both test batteries showed moderate agreement (Cohen's kappa of 0.41). All patients identified by use of the computerized test battery were also identified with the paper and pencil test battery. The paper and pencil test battery identified 6 additional cases.

CONCLUSION

In our study we demonstrated that the incidence of POCD measured with computerized test battery and paper and pencil test battery showed moderate inter-rater reliability. Use of neuropsychological test batteries theoretically covering the same cognitive domains does not automatically lead to the same classification of POCD.

Cognitive effects of lamotrigine versus topiramate as adjunctive therapy in older adults with epilepsy

Older individuals may be more susceptible to cognitive side effects of antiepileptic drugs than are younger adults. This randomized, double-blind study compared the cognitive effects of lamotrigine (median maintenance dosage, 500.0 mg/d) and topiramate (median maintenance dosage, 300.0 mg/d) as adjunctive therapy for 16 weeks in patients ≥50 years of age. Fifty-one patients (lamotrigine, n=25; topiramate, n=26) were enrolled, and 28 patients (lamotrigine, n=15; topiramate, n=13) completed the study. In a combined analysis of all cognitive tests performed, no significant differences between treatment groups were noted. However, analyses of individual cognitive test results revealed that lamotrigine-treated patients had significantly better results on the Controlled Oral Word Association Test and the Symbol-Digit Modalities Test, whereas topiramate-treated patients had significantly more favorable results on the Digit Cancellation Test and the Rey Auditory-Verbal Learning Test. Larger studies are needed to further clarify the differences in the cognitive effects of lamotrigine and topiramate in older patients.

Treatment of cognitive dysfunction in chronic schizophrenia by augmentation of atypical antipsychotics with buspirone, a partial 5-HT(1A) receptor agonist

OBJECTIVES

To assess effects of a semi-acute administration of buspirone in comparison to a placebo on cognitive function and negative symptoms in patients with schizophrenia and schizoaffective disorder.

METHODS

In a 6-week, double-blind, placebo-controlled, independent groups study 18 subjects (14 males, four females) received in random order either placebo or buspirone (15-30 mg/day). A neuropsychological assessment using the Hopkins verbal learning test (HVLT) simple reaction time (SRT), choice reaction time (CRT), n-back spatial working memory task and the stroop colour and word test was performed at baseline and final visit. Symptom rating scales were administered at testing weeks 0, 2, 4 and 6.

RESULTS

Repeated measures ANOVA was used to examine changes in performance on tests over time. There were no statistically significant differences between placebo and buspirone treatments on either cognitive function measures or symptom ratings.

CONCLUSION

Semi-acute adjunct treatment with buspirone may be too short to be clinically efficacious in patients with schizophrenia. Intrinsic activation of 5-HT(1A) receptors by atypical antipsychotics may hinder the ability of buspirone to further improve cognitive functions. Buspirone did not affect clinical outcomes for this chronically ill group of patients being treated with atypical antipsychotic drugs.

Validity of the CogState brief battery: relationship to standardized tests and sensitivity to cognitive impairment in mild traumatic brain injury, schizophrenia, and AIDS dementia complex

This study examined the validity of the four standard psychological paradigms that have been operationally defined within the CogState brief computerized cognitive assessment battery. Construct validity was determined in a large group of healthy adults. CogState measures of processing speed, attention, working memory, and learning showed strong correlations with conventional neuropsychological measures of these same constructs (r's = .49 to .83). Criterion validity was determined by examining patterns of performance on the CogState tasks in groups of individuals with mild head injury, schizophrenia, and AIDS dementia complex. Each of these groups was impaired on the CogState performance measures (Cohen's d's = -.60 to -1.80) and the magnitude and nature of this impairment was qualitatively and quantitatively similar in each group. Taken together, the results suggest that the cognitive paradigms operationally defined in the CogState brief battery have acceptable construct and criterion validity in a neuropsychological context.

Practice Effects Associated with the Repeated Assessment of Cognitive Function Using the CogState Battery at 10-minute, One Week and One Month Test-retest Intervals

There are many situations in which cognitive tests need to be administered on more than two occasions and at very brief test-retest intervals to detect change in group performance. However, previous literature has not specifically addressed these important issues. The main aim of the current study was to examine these two factors by using a computerized cognitive battery designed specifically for the repeated assessment of cognition (i.e., CogState) in healthy young adult individuals. A further aim of the study was to examine how many times the battery needed to be completed before performance, as measured by the battery, stabilized. Forty-five adults (age range: 18-40 years) completed the battery four times at 10-minute test-retest intervals, and a fifth time at an interval of one week. The results illustrated that when brief test-retest intervals were used (i.e., 10 minutes), performance stabilized after the second assessment, as significant practice effects were generally observed between the first and the second assessments. Practice effects were also observed on some of the tasks at a one-week test-retest interval. Due to these findings, 55 adults (age range: 18-40 years) completed the battery twice at 10-minute test-retest intervals (i.e., to eliminate the initial practice effect), and a third time at an interval of one month. No practice effects were observed. The implications of the results are discussed in terms of methods that can be adopted in order to minimize practice effects when this particular cognitive battery is used.

A prospective observational study of the effect of night duty on the cognitive function of anaesthetic registrars

The issue of fatigue in hospital medical staff represents a potential health and safety risk to both staff and patients, and is receiving worldwide interest. We aimed to characterize the cognitive performance of anaesthetic registrars before and after a series of night shifts. We enrolled nine full-time anaesthetic trainees in an Australian adult tertiary-referral hospital. We conducted a cross-over observational study which tested cognitive performance in participants before and after seven consecutive night shifts and compared this with performance before and after seven consecutive day shifts. Cognitive function was measured using a computerized assessment tool. Participants completed a mean of 62.5% of the requested testing (seven participants completed 87%). There was no significant change in performance before or after any day shift, nor at the commencement of each night shift. There was near perfect accuracy in performance in all tests at all times. There was a statistically significant deterioration in speed of performance for detection and identification tasks at the end of night shift as the week progressed. Anaesthetic registrars demonstrate a significant decline in cognitive performance after a series of night shifts.

Management of the critically ill geriatric patient

OBJECTIVE

To review the effect of an aging society on the utilization of critical care services and the physiology of aging as it applies to critical illness and prognosis and management issues in the intensive care unit (ICU).

DATA SOURCE

MEDLINE, Embase, and citation review of relevant primary and review articles.

DATA SYNTHESIS

Elderly patients (age of >65 yrs) currently account for 42-52% of ICU admissions and for almost 60% of all ICU days. Aging is associated with decreased cardiopulmonary and renal reserve and with a high rate of co-morbidities, increasing the risks of the elderly developing progressive organ failure. Elderly ICU patients are at a particularly high risk of developing delirium, which is associated with significant morbidity. Severity of illness and age are the important factors determining ICU survival. Age and functional status before ICU admission are the major determinants of survival at 6 and 12 months after ICU discharge. Age alone should not be used to triage ICU patients; the decision to admit an elderly patient to an ICU should be based on the patients co-morbidities, acuity of illness, prehospital functional status, and preferences with regard to life-sustaining treatment.

CONCLUSIONS

The management of critically ill elderly patients is a complex issue and involves an understanding of the changing demographics of our society and the physiology of aging. The reality of our aging society dictates that we must focus on how to best care for the elderly who develop critical illness.

Comparison of xenon with propofol for supplementary general anaesthesia for knee replacement: a randomized study

BACKGROUND

Xenon anaesthesia is associated with rapid recovery and may also offer protection against neuronal damage. The aim of this study was to compare xenon with propofol for supplementary general anaesthesia in patients undergoing knee replacement in spinal anaesthesia.

METHODS

In total, 39 patients aged 60 or over were randomized to xenon 50-70% or propofol 3-5 mg kg(-1) h(-1). Vital signs and emergence time were recorded and cognitive function was assessed before operation, at discharge between the third and the fifth day and at 3 months using four neuropsychological tests.

RESULTS

Propofol supplementation was necessary in six xenon patients (29%) because of detectable movement of the upper body. Emergence time was significantly shorter with xenon (260 s for xenon and 590 s for propofol, P=0.001). There was no significant difference between the groups in blood pressure, heart rate, ventilatory frequency or end-tidal carbon dioxide concentration. No difference could be detected in cognitive function, which may be attributed to insufficient sample-size rather than the absence of a true difference.

CONCLUSIONS

Xenon was well tolerated for supplementary general anaesthesia in elderly spontaneously breathing patients but supplementation may be necessary. Compared with propofol, emergence was faster with xenon. A larger sample-size is needed if cognitive function is to be addressed.

Detection of Postoperative Cognitive Decline After Coronary Artery Bypass Graft Surgery is Affected by the Number of Neuropsychological Tests in the Assessment Battery

BACKGROUND

The assessment of postoperative cognitive dysfunction after coronary artery bypass graft surgery is made with the repeated administration of cognitive tests. This classification is vulnerable to error, and it has been suggested that increasing the number of tests in a battery while maintaining constant inclusion criteria for postoperative cognitive dysfunction increases the rate of false positive classification of deterioration. The current study tested this by applying a constant rule for cognitive dysfunction using combinations of two to seven cognitive tests.

METHODS

Two hundred and four coronary artery bypass graft patients (surgical) and 90 healthy nonsurgical controls aged 55 years or older completed a battery of cognitive tests at baseline (preoperative) and 1 week later (postoperative). In both groups, postoperative cognitive dysfunction was classified using all unique combinations of two to seven cognitive tests when performance deteriorated on two or more tests by at least the value of the baseline standard deviation.

RESULTS

The average incidence of cognitive dysfunction progressively increased in both groups as the number of cognitive tests increased from two (surgical: 13.3%; control: 3.1%) to seven tests (surgical: 49.4%; control: 41.1%).

CONCLUSIONS

Increasing the number of tests used to classify postoperative cognitive dysfunction appears to increase the sensitivity to change in the coronary artery bypass graft group. However, accompanying false positive classifications suggest that this improved sensitivity reflected increased error. Future rules for postoperative cognitive dysfunction need to account for this error and include a control group.

Repeated assessment of cognition in children and the measurement of performance change

There is limited understanding of the problems associated with repeated neuropsychological assessment in children, including the statistics used to guide decisions about cognitive change. This study investigated the utility of a computerized assessment battery that was specifically designed for the repeated assessment of cognitive function in children. Eighty-seven participants aged 8 to 12 years completed the battery four times within a 2-hour testing session. The results support the application of this assessment battery for measuring cognitive change in children. A novel method for calculating measurement error is employed, and its use in the detection of cognitive change in individual children is discussed. An estimate of the measurement error within each of the tests is provided, and recommendations are made regarding the application of this assessment battery for measuring cognitive change in children.

Assessing cognitive function in cancer patients

GOALS OF WORK

Some patients with cancer suffer cognitive impairment after chemotherapy. A brief, sensitive instrument is required to screen patients for cognitive impairment. In this study, we compare three possible screening instruments.

MATERIALS AND METHODS

Cancer patients (n=31) who had received adjuvant chemotherapy within 2 years underwent cognitive evaluation on three occasions. Fluent English speakers (n=20) completed the High Sensitivity Cognitive Screen (HSCS), the computer-based Headminder and CogHealth, and the Functional Assessment of Cancer Therapy-cognitive function (FACT-COG) questionnaire. Patients not fluent in English (NESB) (n=11) performed CogHealth and Headminder.

RESULTS

The patients were aged 31-65 years, and 94% were women with breast cancer. At baseline, 6 of 20 (30%) had moderate-severe cognitive impairment on HSCS, 17 of 31 (55%) had scores greater than one standard deviation (SD) below the mean for normative data in one to two of three domains on Headminder, and on CogHealth, 8 of 31 (26%) were greater than one SD below the mean in at least two of six domains. A large practice effect was seen for the HSCS, with moderate-severe cognitive impairment decreasing from 30 to 5% between the first and second assessment. On FACT-COG, 9 of 19 patients (47%) rated their cognition as greater than one SD below that of a pre-chemotherapy breast cancer control group, with impact on quality of life greater than one SD below for 10 of 19 (53%) patients. No correlation was seen between objective cognitive testing and the FACT-COG.

CONCLUSIONS

CogHealth and Headminder were suitable for NESB patients. The HSCS is not recommended for longitudinal studies with short intervals between testing due to practice effect. There is poor correlation between the patients' perception of their cognitive impairment and the objective tests.

Cognition in the days following concussion: comparison of symptomatic versus asymptomatic athletes

BACKGROUND

Concussion is a common neurological injury occurring during contact sport. Current guidelines recommend that no athlete should return to play while symptomatic or displaying cognitive dysfunction. This study compared post-concussion cognitive function in recently concussed athletes who were symptomatic/asymptomatic at the time of assessment with that of non-injured (control) athletes.

METHODS

Prospective study of 615 male Australian Rules footballers. Before the season, all participants (while healthy) completed a battery of baseline computerised (CogSport) and paper and pencil cognitive tasks. Sixty one injured athletes (symptomatic = 25 and asymptomatic = 36) were reassessed within 11 days of being concussed; 84 controls were also reassessed. The serial cognitive function of the three groups was compared using analysis of variance.

RESULTS

The performance of the symptomatic group declined at the post-concussion assessment on computerised tests of simple, choice, and complex reaction times compared with the asymptomatic and control groups. The magnitude of changes was large according to conventional statistical criteria. On paper and pencil tests, the symptomatic group displayed no change at reassessment, whereas large improvements were seen in the other two groups.

CONCLUSION

Injured athletes experiencing symptoms of concussion displayed impaired motor function and attention, although their learning and memory were preserved. These athletes displayed no change in performance on paper and pencil tests in contrast with the improvement observed in asymptomatic and non-injured athletes. Athletes experiencing symptoms of concussion should be withheld from training and competition until both symptoms and cognitive dysfunction have resolved.

Cognitive function in growth hormone deficiency and growth hormone replacement

There is converging evidence from neuropsychological studies that growth hormone (GH) is associated with cognitive function. The aim of the current study was to review the existing neuropsychological literature for studies in which cognitive assessment had been conducted in patients with GH deficiency (GHD), and where change in cognitive function had been assessed following treatment with GH. Studies that have investigated relationships between GH and cognitive function and those that have developed methodological and statistical approaches that could be useful in future GH studies were identified. In this review, GH levels were found to be associated with cognitive function. Untreated individuals with GHD showed reliable impairment in memory and attentional functions when compared with matched controls. Appropriately designed prospective studies also indicated that cognitive function improved with GH treatment. It was concluded that individuals with GHD do show cognitive impairment and that this is ameliorated to some extent by GH treatment. It is now important to establish the clinical importance of these findings, and further work is required to understand better the nature, magnitude and meaning of GH-related cognitive impairments and improvements.