Visual Rating Scales of White Matter Hyperintensities and Atrophy: Comparison of Computed Tomography and Magnetic Resonance Imaging

GOAL

Magnetic resonance imaging (MRI) is the preferred modality for research on structural age-related brain changes. However, computed tomography (CT) is widely available and has practical and cost advantages over MRI for large-scale brain imaging research studies in acutely unwell patients. However, the relationships between MRI and CT measures of white matter hyperintensities (WMH) and atrophy are unclear. We examined the relationships between visual ratings of WMH, atrophy, and old infarcts in patients who had both CT and MRI scans.

MATERIALS AND METHODS

Patients who had both CT and MRI scans in the International Stroke Trial-3 were studied. In both modalities, 2 raters independently completed standardized visual rating scales for WMH, and for central and superficial atrophy using a 5-point scale. In addition, 1 rater recorded old infarcts according to size and location.

FINDINGS

Seventy patients with a mean age of 69 years were studied. There were moderate to substantial intrarater CT-MRI agreements for periventricular components of WMH scales (weighted Κappa = .55-.75). Agreements for basal ganglia ratings were lower (weighted Κappa = .18-.44), partly because of the misclassification of prominent perivascular spaces. Atrophy scales showed moderate to substantial CT-MRI agreements (weighted Κappa = .44-.70). MRI was more sensitive in the detection of smaller infarcts and cavitated lesions.

CONCLUSIONS

Standardized visual rating scales of white matter lesions and atrophy mostly show substantial agreement between CT and MRI. Clinical CT scans have a strong potential for wider exploitation in research studies, particularly in acutely unwell populations.

The use of clonidine in elderly patients with delirium; pharmacokinetics and hemodynamic responses

Background

The Oslo Study of Clonidine in Elderly Patients with Delirium (LUCID) is an RCT investigating the effect of clonidine in medical patients > 65 years with delirium. To assess the dosage regimen and safety measures of this study protocol, we measured the plasma concentrations and hemodynamic effects of clonidine in the first 20 patients.

Methods

Patients were randomised to clonidine (n = 10) or placebo (n = 10). The treatment group was given a loading dose (75μg every 3rd hour up to a maximum of 4 doses) to reach steady state, and further 75μg twice daily until delirium free for 2 days, discharge or a maximum of 7 days. Blood pressure (BP) and heart rate (HR) were measured just before every dose. If the systolic BP was < 100 mmHg or HR < 50 beats per minute the next dose was omitted. Plasma concentrations of clonidine were measured 3 h after each drug intake on day 1, just before intake (day 2 and at steady state day 4–6) and 3 h after intake at steady state (C_max). Our estimated pre-specified plasma concentration target range was 0.3–0.7μg/L.

Results

3 h after the first dose of 75μg clonidine, plasma concentration levels rose to median 0.35 (range 0.24–0.40)μg/L. Median trough concentration (C₀) at day 2 was 0.70 (0.47–0.96)μg/L. At steady state, median C₀ was 0.47 (0.36–0.76)μg/L, rising to C_max 0.74 (0.56–0.95)μg/L 3 h post dose. A significant haemodynamic change from baseline was only found at a few time-points during the loading doses within the clonidine group. There was however extensive individual BP and HR variation in both the clonidine and placebo groups, and when comparing the change scores (delta values) between the clonidine and the placebo groups, there were no significant differences.

Conclusions

The plasma concentration of clonidine was at the higher end of the estimated therapeutic range. Hemodynamic changes during clonidine treatment were as expected, with trends towards lower blood pressure and heart rate in patients treated with clonidine, but with dose adjustments based on SBP this protocol appears safe.

Trial registration

ClinicalTrials.gov NCT01956604, 09.25.2013. EudraCT Number: 2013–000815-26, 03.18.2013. Enrolment of first participant: 04.24.2014.

Reduced level of arousal and increased mortality in adult acute medical admissions: a systematic review and meta-analysis

Background

Reduced level of arousal is commonly observed in medical admissions and may predict in-hospital mortality. Delirium and reduced level of arousal are closely related. We systematically reviewed and conducted a meta-analysis of studies in adult acute medical patients of the relationship between reduced level of arousal on admission and in-hospital mortality.

Methods

We conducted a systematic review (PROSPERO: CRD42016022048), searching MEDLINE and EMBASE. We included studies of adult patients admitted with acute medical illness with level of arousal assessed on admission and mortality rates reported. We performed meta-analysis using a random effects model.

Results

From 23,941 studies we included 21 with 14 included in the meta-analysis. Mean age range was 33.4 - 83.8 years. Studies considered unselected general medical admissions (8 studies, n=13,039) or specific medical conditions (13 studies, n=38,882). Methods of evaluating level of arousal varied. The prevalence of reduced level of arousal was 3.1%-76.9% (median 13.5%). Mortality rates were 1.7%-58% (median 15.9%). Reduced level of arousal was associated with higher in-hospital mortality (pooled OR 5.71; 95% CI 4.21-7.74; low quality evidence: high risk of bias, clinical heterogeneity and possible publication bias).

Conclusions

Reduced level of arousal on hospital admission may be a strong predictor of in-hospital mortality. Most evidence was of low quality. Reduced level of arousal is highly specific to delirium, better formal detection of hypoactive delirium and implementation of care pathways may improve outcomes. Future studies to assess the impact of interventions on in-hospital mortality should use validated assessments of both level of arousal and delirium.

Electronic supplementary material

The online version of this article (10.1186/s12877-017-0661-7) contains supplementary material, which is available to authorized users.

Predicting Discharge to Institutional Long-Term Care After Stroke: A Systematic Review and Metaanalysis

BACKGROUND/OBJECTIVES

Stroke is a leading cause of disability worldwide, and a significant proportion of stroke survivors require long-term institutional care. Understanding who cannot be discharged home is important for health and social care planning. Our aim was to establish predictive factors for discharge to institutional care after hospitalization for stroke.

DESIGN

We registered and conducted a systematic review and meta-analysis (PROSPERO: CRD42015023497) of observational studies. We searched MEDLINE, EMBASE, and CINAHL Plus to February 2017. Quantitative synthesis was performed where data allowed.

SETTING

Acute and rehabilitation hospitals.

PARTICIPANTS

Adults hospitalized for stroke who were newly admitted directly to long-term institutional care at the time of hospital discharge.

MEASUREMENTS

Factors associated with new institutionalization.

RESULTS

From 10,420 records, we included 18 studies (n = 32,139 participants). The studies were heterogeneous and conducted in Europe, North America, and East Asia. Eight studies were at high risk of selection bias. The proportion of those surviving to discharge who were newly discharged to long-term care varied from 7% to 39% (median 17%, interquartile range 12%), and the model of care received in the long-term care setting was not defined. Older age and greater stroke severity had a consistently positive association with the need for long-term care admission. Individuals who had a severe stroke were 26 times as likely to be admitted to long-term care than those who had a minor stroke. Individuals aged 65 and older had a risk of stroke that was three times as great as that of younger individuals. Potentially modifiable factors were rarely examined.

CONCLUSION

Age and stroke severity are important predictors of institutional long-term care admission directly from the hospital after an acute stroke. Potentially modifiable factors should be the target of future research. Stroke outcome studies should report discharge destination, defining the model of care provided in the long-term care setting.

Altered cortical brain activity in end stage liver disease assessed by multi-channel near-infrared spectroscopy: Associations with delirium

Delirium is a common and serious psychiatric syndrome caused by an underlying medical condition. It is associated with significant mortality and increased healthcare resource utilization. There are few biological markers of delirium, perhaps related to the etiologic heterogeneity of the syndrome. Functional near-infrared spectroscopy (fNIRS) is an optical topography system to measure changes in the concentration of oxygenated hemoglobin ([oxy-Hb]) in the cerebral cortex. We examined whether altered cortical brain activity in delirious patients with end stage liver disease (ESLD) is detected by fNIRS. We found that the [oxy-Hb] change during the verbal fluency task (VFT) was reduced in patients with ESLD compared with healthy controls (HC) in the prefrontal and bi-temporal regions. The [oxy-Hb] change during the sustained attention task (SAT) was elevated in patients with ESLD compared to HC in the prefrontal and left temporal regions. Notably, [oxy-Hb] change in the left dorsolateral prefrontal cortex during SAT showed a positive correlation with the severity of delirium. Our results suggest that [oxy-Hb] change in the prefrontal cortex during the sustained attention task measured with fNIRS might serve as a biological marker associated with delirium in ESLD patients.

Predicting discharge to institutional long-term care following acute hospitalisation: a systematic review and meta-analysis

Background

moving into long-term institutional care is a significant life event for any individual. Predictors of institutional care admission from community-dwellers and people with dementia have been described, but those from the acute hospital setting have not been systematically reviewed. Our aim was to establish predictive factors for discharge to institutional care following acute hospitalisation.

Methods

we registered and conducted a systematic review (PROSPERO: CRD42015023497). We searched MEDLINE; EMBASE and CINAHL Plus in September 2015. We included observational studies of patients admitted directly to long-term institutional care following acute hospitalisation where factors associated with institutionalisation were reported.

Results

from 9,176 records, we included 23 studies (n = 354,985 participants). Studies were heterogeneous, with the proportions discharged to a care home 3–77% (median 15%). Eleven studies (n = 12,642), of moderate to low quality, were included in the quantitative synthesis. The need for institutional long-term care was associated with age (pooled odds ratio (OR) 1.02, 95% confidence intervals (CI): 1.00–1.04), female sex (pooled OR 1.41, 95% CI: 1.03–1.92), dementia (pooled OR 2.14, 95% CI: 1.24–3.70) and functional dependency (pooled OR 2.06, 95% CI: 1.58–2.69).

Conclusions

discharge to long-term institutional care following acute hospitalisation is common, but current data do not allow prediction of who will make this transition. Potentially important predictors evaluated in community cohorts have not been examined in hospitalised cohorts. Understanding these predictors could help identify individuals at risk early in their admission, and support them in this transition or potentially intervene to reduce their risk.

New institutionalisation following acute hospital admission: a retrospective cohort study

Background

institutionalisation following acute hospital admission is common and yet poorly described, with policy documents advising against this transition.

Objective

to characterise the individuals admitted to a care home on discharge from an acute hospital admission and to describe their assessment.

Design and setting

a retrospective cohort study of people admitted to a single large Scottish teaching hospital.

Subjects

100 individuals admitted to the acute hospital from home and discharged to a care home.

Methods

a single researcher extracted data from ward-based case notes.

Results

people discharged to care homes were predominantly female (62%), widowed (52%) older adults (mean 83.6 years) who lived alone (67%). About 95% had a diagnosed cognitive disorder or evidence of cognitive impairment. One-third of cases of delirium were unrecognised. Hospital stays were long (median 78.5 days; range 14-231 days) and transfers between settings were common. Family request, dementia, mobility, falls risk and behavioural concerns were the commonest reasons for the decision to admit to a care home. About 55% were in the acute hospital when the decision for a care home was made and 44% of that group were discharged directly from the acute hospital.

Conclusions

care home admission from hospital is common and yet there are no established standards to support best practice. Decisions should involve the whole multidisciplinary team in partnership with patients and families. Documentation of assessment in the case notes is variable. We advocate the development of interdisciplinary standards to support the assessment of this vulnerable and complex group of patients.

Stress in childhood, adolescence and early adulthood, and cortisol levels in older age

The glucocorticoid hypothesis suggests that overexposure to stress may cause permanent upregulation of cortisol. Stress in youth may therefore influence cortisol levels even in older age. Using data from the 6-Day Sample, we investigated the effects of high stress in childhood, adolescence and early adulthood - as well as individual variables contributing to these measures; parental loss, social deprivation, school and home moves, illness, divorce and job instability - upon cortisol levels at age 77 years. Waking, waking +45 min (peak) and evening salivary cortisol samples were collected from 159 participants, and the 150 who were not using steroid medications were included in this study. After correcting for multiple comparisons, the only significant association was between early-adulthood job instability and later-life peak cortisol levels. After excluding participants with dementia or possible mild cognitive impairment, early-adulthood high stress showed significant associations with lower evening and mean cortisol levels, suggesting downregulation by stress, but these results did not survive correction for multiple comparisons. Overall, our results do not provide strong evidence of a relationship between stress in youth and later-life cortisol levels, but do suggest that some more long-term stressors, such as job instability, may indeed produce lasting upregulation of cortisol, persisting into the mid-to-late seventies.

Association of Delirium With Cognitive Decline in Late Life: A Neuropathologic Study of 3 Population-Based Cohort Studies

IMPORTANCE

Delirium is associated with accelerated cognitive decline. The pathologic substrates of this association are not yet known, that is, whether they are the same as those associated with dementia, are independent, or are interrelated.

OBJECTIVE

To examine whether the accelerated cognitive decline observed after delirium is independent of the pathologic processes of classic dementia.

DESIGN, SETTING, AND PARTICIPANTS

Harmonized data from 987 individual brain donors from 3 observational cohort studies with population-based sampling (Vantaa 85+, Cambridge City Over-75s Cohort, Cognitive Function and Ageing Study) performed from January 1, 1985, through December 31, 2011, with a median follow-up of 5.2 years until death, were used in this study. Neuropathologic assessments were performed with investigators masked to clinical data. Data analysis was performed from January 1, 2012, through December 31, 2013. Clinical characteristics of brain donors were not different from the rest of the cohort. Outcome ascertainment was complete given that the participants were brain donors.

EXPOSURES

Delirium (never vs ever) and pathologic burden of neurofibrillary tangles, amyloid plaques, vascular lesions, and Lewy bodies. Effects modeled using random-effects linear regression and interactions between delirium and pathologic burden were assessed.

OUTCOMES

Change in Mini-Mental State Examination (MMSE) scores during the 6 years before death.

RESULTS

There were 987 participants (290 from Vantaa 85+, 241 from the Cambridge City Over-75s Cohort, and 456 from the Cognitive Function and Ageing Study) with neuropathologic data; mean (SD) age at death was 90 (6.4) years, including 682 women (69%). The mean MMSE score 6 years before death was 24.7 points. The 279 individuals with delirium (75% women) had worse initial scores (-2.8 points; 95% CI, -4.5 to -1.0; P < .001). Cognitive decline attributable to delirium was -0.37 MMSE points per year (95% CI, -0.60 to -0.13; P < .001). Decline attributable to the pathologic processes of dementia was -0.39 MMSE points per year (95% CI, -0.57 to -0.22; P < .001). However, the combination of delirium and the pathologic processes of dementia resulted in the greatest decline, in which the interaction contributed an additional -0.16 MMSE points per year (95% CI, -0.29 to -0.03; P = .01). The multiplicative nature of these variables resulted in individuals with delirium and the pathologic processes of dementia declining 0.72 MMSE points per year faster than age-, sex-, and educational level-matched controls.

CONCLUSIONS AND RELEVANCE

Delirium in the presence of the pathologic processes of dementia is associated with accelerated cognitive decline beyond that expected for delirium or the pathologic process itself. These findings suggest that additional unmeasured pathologic processes specifically relate to delirium. Age-related cognitive decline has many contributors, and these findings at the population level support a role for delirium acting independently and multiplicatively to the pathologic processes of classic dementia.

Challenges and opportunities in understanding dementia and delirium in the acute hospital

In an Essay, Andrew Jackson and colleagues discuss challenges in the diagnosis and management of older people with dementia and delirium in acute hospitals.

Diagnostic test accuracy of informant-based tools to diagnose dementia in older hospital patients with delirium: a prospective cohort study

BACKGROUND

delirium and dementia co-exist commonly in hospital. Older people with delirium have high rates of undiagnosed dementia, but delirium affects the use of cognitive testing in dementia diagnosis. Novel methods to detect dementia in delirium are needed. The purpose of the study was to investigate the diagnostic test accuracy of informant tools to detect dementia in hospitalised older people with delirium.

METHODS

the presence of dementia on admission was assessed using the short form of the Informant Questionnaire of Cognitive Decline in the Elderly (IQCODE-SF) and Alzheimer's Disease 8 (AD8) in people over 70 years old with delirium. Reference standard diagnosis was made using Diagnostic and Statistical Manual of Mental Disorders fourth edition (DSM-IV) criteria at 3 months. The main outcome measures were the diagnostic test accuracy of the IQCODE-SF and the AD8 in diagnosing DSM-IV dementia.

RESULTS

dementia prevalence at 3 months was 61%. The area under the receiver operating characteristic curve (AUROC) was 0.93 (P < 0.0005) for admission IQCODE-SF and 0.91 (P < 0.0005) for admission AD8. An IQCODE-SF test result of >3.82 on admission had a sensitivity of 0.91 (0.79-0.97) and specificity of 0.93 (0.76-0.99) for detecting dementia. An AD8 of >6 had a sensitivity of 0.83 (0.69-0.92) and specificity of 0.90 (0.72-0.97) for detecting dementia.

CONCLUSION

the IQCODE-SF and AD8 are sensitive and specific tools to detect prior dementia in older people with delirium. The routine use of either tool in practice could have important clinical impact, by improving the recognition and hence management of those with dementia.

Undiagnosed long-term cognitive impairment in acutely hospitalised older medical patients with delirium: a prospective cohort study

BACKGROUND

delirium and dementia are common in the general hospital, being present in nearly 50% of older unselected admissions to hospital. Cognitive impairment is a risk factor for delirium, but the prevalence of previously undiagnosed cognitive impairment (dementia or mild cognitive impairment) in patients with delirium is unknown.

METHODS

we performed a prospective cohort study of people over 70 years admitted to hospital with delirium to establish the prevalence of previously unrecognised prior cognitive impairment. Delirium was diagnosed at baseline using the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR). Mild cognitive impairment and dementia were diagnosed 3 months following recruitment in survivors using the International Working Group on Mild Cognitive Impairment criteria and DSM-IV criteria, respectively.

RESULTS

delirium was identified in 17.9% of older patients, and 82 participants with delirium were assessed at 3 months: 5 (6%) had persistent delirium, 14 (17%) had mild cognitive impairment and 47 (57%) had dementia. In 17 participants with prior dementia and 14 with prior mild cognitive impairment, the diagnosis had been unrecognised, amounting to 31/82 (38%) of all patients with delirium having some form of previously undiagnosed cognitive impairment.

CONCLUSION

given that over 1/3 of older patients with delirium were found to have a previously undiagnosed cognitive impairment, the development and evaluation of services to follow-up and manage patients with delirium are warranted.

Increasing delirium skills at the front door: results from a repeated survey on delirium knowledge and attitudes

BACKGROUND

delirium is under-recognised in comparison to other common and serious acute disorders. A 2006 survey of UK junior doctors (not undertaking specialist training) identified poor knowledge of the diagnostic criteria and treatment of delirium. We hypothesised that increased prominence accorded to delirium in the form of national initiatives and guidelines may have had an impact on understanding among junior doctors.

OBJECTIVE

we repeated a multi-centre survey of knowledge of and attitudes to delirium in junior doctors (not undertaking specialist training) assessing unselected acute medical presentations (the 'medical take').

DESIGN

questionnaire-based survey in 48 acute hospitals in UK and Ireland.

METHODS

we used questionnaires designed to test understanding of delirium, including prevalence, knowledge of the DSM-IV diagnostic criteria, use of specific screening tools, association with adverse outcomes and pharmacological management.

RESULTS

one thousand two hundred and fifteen trainee physicians participated. Compared with the 2006 cohort, improvements were seen in 9 of 17 knowledge-based questions and overall score improved in the 2013 cohort. Nonetheless, significant deficits in knowledge, particularly for the diagnostic criteria for delirium, remained.

CONCLUSIONS

despite improvements in some aspects of delirium knowledge, the diagnostic criteria for delirium remain poorly understood. Challenges remain in ensuring adequate training for junior doctors in delirium.

Cerebrospinal fluid levels of neopterin are elevated in delirium after hip fracture

BACKGROUND

The inflammatory cell product neopterin is elevated in serum before and during delirium. This suggests a role for disordered cell-mediated immunity or oxidative stress. Cerebrospinal fluid (CSF) neopterin levels reflect brain neopterin levels more closely than serum levels. Here we hypothesized that CSF neopterin levels would be higher in delirium.

METHODS

In this prospective cohort study, 139 elderly patients with acute hip fracture were recruited in Oslo and Edinburgh. Delirium was diagnosed with the confusion assessment method performed daily pre-operatively and on the first 5 days post-operatively. Paired CSF and blood samples were collected at the onset of spinal anaesthesia. Neopterin levels were measured using high-performance liquid chromatography.

RESULTS

Sixty-four (46 %) of 139 hip fracture patients developed delirium perioperatively. CSF neopterin levels were higher in delirium compared to controls (median 29.6 vs 24.7 nmol/mL, p = 0.003), with highest levels in patients who developed delirium post-operatively. Serum neopterin levels were also higher in delirium (median 37.0 vs 27.1 nmol/mL, p = 0.003). CSF neopterin remained significantly associated with delirium after controlling for relevant risk factors. Higher neopterin levels were associated with poorer outcomes (death or new institutionalization) 1 year after surgery (p = 0.02 for CSF and p = 0.03 for serum).

CONCLUSIONS

This study is the first to examine neopterin in CSF from patients with delirium. Our findings suggest potential roles for activation of cell-mediated immune responses or oxidative stress in the delirium process. High levels of serum or CSF neopterin in hip fracture patients may also be useful in predicting poor outcomes.

Detecting Delirium Superimposed on Dementia: Evaluation of the Diagnostic Performance of the Richmond Agitation and Sedation Scale

OBJECTIVES

Delirium disproportionately affects patients with dementia and is associated with adverse outcomes. The diagnosis of delirium superimposed on dementia (DSD), however, can be challenging due to several factors, including the absence of caregivers or the severity of preexisting cognitive impairment. Altered level of consciousness has been advocated as a possible useful indicator of delirium in this population. Here we evaluated the performance of the Richmond Agitation and Sedation Scale (RASS) and the modified-RASS (m-RASS), an ultra-brief measure of the level of consciousness, in the diagnosis of DSD.

DESIGN

Multicenter prospective observational study. RASS and m-RASS results were analyzed together, labeled RASS/m-RASS.

SETTING

Acute geriatric wards, in-hospital rehabilitation, emergency department.

PARTICIPANTS

Patients 65 years and older with dementia.

MEASUREMENTS

Delirium was diagnosed with the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) or with the Delirium Rating Scale-Revised (DRS-R-98), or with the 4 A's Test (4AT). Dementia was detected with the Clinical Dementia Rating (CDR) Scale, the Short Form-Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) or via the clinical records.

RESULTS

Of the 645 patients included, 376 (58%) had delirium. According to the instrument used to evaluate delirium, the prevalence was 66% with the 4AT, 23% with the DSM, and 100% with the DRS-R-98. Overall a RASS/m-RASS score other than 0 was 70.5% sensitive (95% confidence interval [CI] 65.9%-75.1%) and 84.8% (CI 80.5%-89.1%) specific for DSD. Using a RASS/m-RASS value greater than +1 or less than -1 as a cutoff, the sensitivity was 30.6% (CI 25.9%-35.2%) and the specificity was 95.5% (CI 93.1%-98.0%). The sensitivity and the specificity did not greatly vary according to the method of delirium diagnosis and the dementia ascertainment, although the specificity was slightly higher when the DSM and the IQCODE were used.

CONCLUSION

In older patients admitted to different clinical settings, the RASS and m-RASS analyzed as a single group had moderate sensitivity and very high specificity for the detection of DSD. Level of consciousness is therefore a valuable clinical indicator that should form part of delirium screening strategies, although for higher sensitivity other methods of assessment should be used.

The protocol of the Oslo Study of Clonidine in Elderly Patients with Delirium; LUCID: a randomised placebo-controlled trial

Background

Delirium affects 15% of hospitalised patients and is linked with poor outcomes, yet few pharmacological treatment options exist. One hypothesis is that delirium may in part result from exaggerated and/or prolonged stress responses. Dexmedetomidine, a parenterally-administered alpha2-adrenergic receptor agonist which attenuates sympathetic nervous system activity, shows promise as treatment in ICU delirium. Clonidine exhibits similar pharmacodynamic properties and can be administered orally. We therefore wish to explore possible effects of clonidine upon the duration and severity of delirium in general medical inpatients.

Methods/Design

The Oslo Study of Clonidine in Elderly Patients with Delirium (LUCID) is a randomised, placebo-controlled, double-blinded, parallel group study with 4-month prospective follow-up. We will recruit 100 older medical inpatients with delirium or subsyndromal delirium in the acute geriatric ward. Participants will be randomised to oral clonidine or placebo until delirium free for 2 days (Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria), or after a maximum of 7 days treatment. Assessment of haemodynamics (blood pressure, heart rate and electrocardiogram) and delirium will be performed daily until discharge or a maximum of 7 days after end of treatment. The primary endpoint is the trajectory of delirium over time (measured by Memorial Delirium Assessment Scale). Secondary endpoints include the duration of delirium, use of rescue medication for delirium, pharmacokinetics and pharmacodynamics of clonidine, cognitive function after 4 months, length of hospital stay and need for institutionalisation.

Discussion

LUCID will explore the efficacy and safety of clonidine for delirium in older medical inpatients.

Trial registration

ClinicalTrials.gov NCT01956604. EudraCT Number: 2013-000815-26

Towards an understanding of why undergraduate teaching about delirium does not guarantee gold-standard practice--results from a UK national survey

BACKGROUND

delirium is common and serious, yet frequently missed by medical staff. It is known that delirium is widely taught and examined in UK medical schools; however, what is taught, and how such teaching is delivered, remains unknown. The primary aim of this study was to determine the content of UK undergraduate medical education about delirium and establish how it is delivered. A secondary aim was to highlight and share examples of gold-standard teaching on delirium.

METHODS

all UK undergraduate medical schools were invited to complete a survey. Schools were asked to describe how delirium was taught and to provide delirium-related learning outcomes. Learning outcomes were mapped to the three overarching themes outlined in Tomorrow's Doctors (knowledge, skills and attitudes).

RESULTS

24/31 schools (77%) provided responses. In line with previous work, delirium was widely taught and examined. 18/24 schools reported at least one learning outcome that mapped to the knowledge domain, 19/24 for the skills domain and 2/24 for the attitudes domain. 4/24 evaluated the impact of sessions and 3/24 involved patients and the public in teaching. 13/24 schools were confident that exposure to delirium was guaranteed. Innovative teaching methods were reported by a number of schools; weblinks to examples are provided.

DISCUSSION

there was widespread failure to address attitudes on delirium within teaching, to evaluate the impact of sessions, to involve patients and the public in teaching and to guarantee exposure to delirium. Future teaching interventions should be directed at attitudinal outcomes, using a synthesis of clinical experience with multidisciplinary interaction and supportive technologies.

Objective assessment of attention in delirium: a narrative review

OBJECTIVE

Inattention is a core feature of delirium, and valid assessment of attention is central to diagnosis. Methods of measuring attention in delirium can be divided into two broad categories: (i) objective neuropsychological testing; and (ii) subjective grading of behaviour during interview and clinical examination. Here, we review and critically evaluate studies of objective neuropsychological testing of attention in delirium. We examine the implications of these studies for delirium detection and monitoring in clinical practice and research, and how these studies inform understanding of the nature of attentional deficits in delirium.

METHODS

Searches of MEDLINE and ISI Web of Knowledge databases were performed to identify studies in which objective tests of attention had been administered to patients with delirium, who had been diagnosed using DSM or ICD criteria.

RESULTS

Sixteen publications were identified. The attention tests administered in these studies were grouped into the following categories: measures of attention span, vigilance tests, other pen-and-paper tests (e.g. Trail Making Test) and computerised tests of speeded reaction, vigilance and sustained attention. Patients with delirium showed deficits on all tasks, although most tasks were not considered pure measures of attention. Five papers provided data on differential diagnosis from dementia. Cancellation tests, spatial span tests and computerised tests of sustained attention discriminated delirium from dementia. Five studies presented reliability or validity statistics.

CONCLUSIONS

The existing evidence base on objective assessment of attention in delirium is small. Objective testing of attention is underdeveloped but shows considerable promise in clinical practice and research.

Validation of a consensus method for identifying delirium from hospital records

Background

Delirium is increasingly considered to be an important determinant of trajectories of cognitive decline. Therefore, analyses of existing cohort studies measuring cognitive outcomes could benefit from methods to ascertain a retrospective delirium diagnosis. This study aimed to develop and validate such a method for delirium detection using routine medical records in UK and Ireland.

Methods

A point prevalence study of delirium provided the reference-standard ratings for delirium diagnosis. Blinded to study results, clinical vignettes were compiled from participants' medical records in a standardised manner, describing any relevant delirium symptoms recorded in the whole case record for the period leading up to case-ascertainment. An expert panel rated each vignette as unlikely, possible, or probable delirium and disagreements were resolved by consensus.

Results

From 95 case records, 424 vignettes were abstracted by 5 trained clinicians. There were 29 delirium cases according to the reference standard. Median age of subjects was 76.6 years (interquartile range 54.6 to 82.5). Against the original study DSM-IV diagnosis, the chart abstraction method gave a positive likelihood ratio (LR) of 7.8 (95% CI 5.7–12.0) and the negative LR of 0.45 (95% CI 0.40–0.47) for probable delirium (sensitivity 0.58 (95% CI 0.53–0.62); specificity 0.93 (95% CI 0.90–0.95); AUC 0.86 (95% CI 0.82–0.89)). The method diagnosed possible delirium with positive LR 3.5 (95% CI 2.9–4.3) and negative LR 0.15 (95% CI 0.11–0.21) (sensitivity 0.89 (95% CI 0.85–0.91); specificity 0.75 (95% CI 0.71–0.79); AUC 0.86 (95% CI 0.80–0.89)).

Conclusions

This chart abstraction method can retrospectively diagnose delirium in hospitalised patients with good accuracy. This has potential for retrospectively identifying delirium in cohort studies where routine medical records are available. This example of record linkage between hospitalisations and epidemiological data may lead to further insights into the inter-relationship between acute illness, as an exposure, for a range of chronic health outcomes.

Cerebrospinal fluid markers of neuroinflammation in delirium: a role for interleukin-1β in delirium after hip fracture

OBJECTIVE

Exaggerated central nervous system (CNS) inflammatory responses to peripheral stressors may be implicated in delirium. This study hypothesised that the IL-1β family is involved in delirium, predicting increased levels of interleukin-1β (IL-1β) and decreased IL-1 receptor antagonist (IL-1ra) in the cerebrospinal fluid (CSF) of elderly patients with acute hip fracture. We also hypothesised that Glial Fibrillary Acidic Protein (GFAP) and interferon-γ (IFN-γ) would be increased, and insulin-like growth factor 1 (IGF-1) would be decreased.

METHODS

Participants with acute hip fracture aged >60 (N=43) were assessed for delirium before and 3-4 days after surgery. CSF samples were taken at induction of spinal anaesthesia. Enzyme-linked immunosorbent assays (ELISA) were used for protein concentrations.

RESULTS

Prevalent delirium was diagnosed in eight patients and incident delirium in 17 patients. CSF IL-1β was higher in patients with incident delirium compared to never delirium (incident delirium 1.74 pg/ml (1.02-1.74) vs. prevalent 0.84 pg/ml (0.49-1.57) vs. never 0.66 pg/ml (0-1.02), Kruskal-Wallis p=0.03). CSF:serum IL-1β ratios were higher in delirious than non-delirious patients. CSF IL-1ra was higher in prevalent delirium compared to incident delirium (prevalent delirium 70.75 pg/ml (65.63-73.01) vs. incident 31.06 pg/ml (28.12-35.15) vs. never 33.98 pg/ml (28.71-43.28), Kruskal-Wallis p=0.04). GFAP was not increased in delirium. IFN-γ and IGF-1 were below the detection limit in CSF.

CONCLUSION

This study provides novel evidence of CNS inflammation involving the IL-1β family in delirium and suggests a rise in CSF IL-1β early in delirium pathogenesis. Future larger CSF studies should examine the role of CNS inflammation in delirium and its sequelae.

Compensation or inhibitory failure? Testing hypotheses of age-related right frontal lobe involvement in verbal memory ability using structural and diffusion MRI

Functional neuroimaging studies report increased right prefrontal cortex (PFC) involvement during verbal memory tasks amongst low-scoring older individuals, compared to younger controls and their higher-scoring contemporaries. Some propose that this reflects inefficient use of neural resources through failure of the left PFC to inhibit non-task-related right PFC activity, via the anterior corpus callosum (CC). For others, it indicates partial compensation - that is, the right PFC cannot completely supplement the failing neural network, but contributes positively to performance. We propose that combining structural and diffusion brain MRI can be used to test predictions from these theories which have arisen from fMRI studies. We test these hypotheses in immediate and delayed verbal memory ability amongst 90 healthy older adults of mean age 73 years. Right hippocampus and left dorsolateral prefrontal cortex (DLPFC) volumes, and fractional anisotropy (FA) in the splenium made unique contributions to verbal memory ability in the whole group. There was no significant effect of anterior callosal white matter integrity on performance. Rather, segmented linear regression indicated that right DLPFC volume was a significantly stronger positive predictor of verbal memory for lower-scorers than higher-scorers, supporting a compensatory explanation for the differential involvement of the right frontal lobe in verbal memory tasks in older age.

The descriptive epidemiology of delirium symptoms in a large population-based cohort study: results from the Medical Research Council Cognitive Function and Ageing Study (MRC CFAS)

Background

In the general population, the epidemiological relationships between delirium and adverse outcomes are not well defined. The aims of this study were to: (1) construct an algorithm for the diagnosis of delirium using the Geriatric Mental State (GMS) examination; (2) test the criterion validity of this algorithm against mortality and dementia risk; (3) report the age-specific prevalence of delirium as determined by this algorithm.

Methods

Participant and informant data in a randomly weighted subsample of the Cognitive Function and Ageing Study were taken from a standardized assessment battery. The algorithmic definition of delirium was based on the DSM-IV classification. Outcomes were: proportional hazard ratios for death; odds ratios of dementia at 2-year follow-up.

Results

Data from 2197 persons (representative of 13,004) were used, median age 77 years, 64% women. Study-defined delirium was associated with a new dementia diagnosis at two years (OR 8.82, 95% CI 2.76 to 28.2) and death (HR 1.28, 95% CI 1.03 to 1.60), even after adjustment for acute illness severity. Similar associations were seen for study-defined subsyndromal delirium. Age-specific prevalence as determined by the algorithm increased with age from 1.8% in the 65-69 year age group to 10.1% in the ≥85 age group (p < 0.01 for trend). For study-defined subsyndromal delirium, age-specific period prevalence ranged from 8.2% (65-69 years) to 36.1% (≥85 years).

Conclusions

These results demonstrate the possibility of constructing an algorithmic diagnosis for study-defined delirium using data from the GMS schedule, with predictive criterion validity for mortality and dementia risk. These are the first population-based analyses able to account prospectively for both illness severity and an earlier study diagnosis of dementia.

Validation of the 4AT, a new instrument for rapid delirium screening: a study in 234 hospitalised older people

OBJECTIVE

to evaluate the performance of the 4 'A's Test (4AT) in screening for delirium in older patients. The 4AT is a new test for rapid screening of delirium in routine clinical practice.

DESIGN

: prospective study of consecutively admitted elderly patients with independent 4AT and reference standard assessments.

SETTING

: an acute geriatrics ward and a department of rehabilitation.

PARTICIPANTS

two hundred and thirty-six patients (aged ≥70 years) consecutively admitted over a period of 4 months.

MEASUREMENTS

in each centre, the 4AT was administered by a geriatrician to eligible patients within 24 h of admission. Reference standard delirium diagnosis (DSM-IV-TR criteria) was obtained within 30 min by a different geriatrician who was blind to the 4AT score. The presence of dementia was assessed using the Alzheimer's Questionnaire and the informant section of the Clinical Dementia Rating scale. The main outcome measure was the accuracy of the 4AT in diagnosing delirium.

RESULTS

patients were 83.9 ± 6.1 years old, and the majority were women (64%). Delirium was detected in 12.3% (n = 29), dementia in 31.2% (n = 74) and a combination of both in 7.2% (n = 17). The 4AT had a sensitivity of 89.7% and specificity 84.1% for delirium. The areas under the receiver operating characteristic curves for delirium diagnosis were 0.93 in the whole population, 0.92 in patients without dementia and 0.89 in patients with dementia.

CONCLUSIONS

the 4AT is a sensitive and specific method of screening for delirium in hospitalised older people. Its brevity and simplicity support its use in routine clinical practice.

Brain white matter integrity and cortisol in older men: the Lothian Birth Cohort 1936

Elevated glucocorticoid (GC) levels are hypothesized to be deleterious to some brain regions, including white matter (WM). Older age is accompanied by increased between-participant variation in GC levels, yet relationships between WM integrity and cortisol levels in older humans are underexplored. Moreover, it is unclear whether GC-WM associations might be general or pathway specific. We analyzed relationships between salivary cortisol (diurnal and reactive) and general measures of brain WM hyperintensity (WMH) volume, fractional anisotropy (g_FA), and mean diffusivity (g_MD) in 90 males, aged 73 years. Significant associations were predominantly found between cortisol measures and WMHs and g_MD but not g_FA. Higher cortisol at the start of a mild cognitive stressor was associated with higher WMH and g_MD. Higher cortisol at the end was associated with greater WMHs. A constant or increasing cortisol level during cognitive testing was associated with lower g_MD. Tract-specific bases of these associations implicated anterior thalamic radiation, uncinate, and arcuate and inferior longitudinal fasciculi. The cognitive sequelae of these relationships, above other covariates, are a priority for future study.

•

We correlated salivary cortisol and brain white matter (WM) measures in older males.

•

Cortisol was measured diurnally and in reaction to a cognitive challenge.

•

Diffusion tensor magnetic resonance imaging (fractional anisotropy and mean diffusivity) and total hyperintensity volume measured WM integrity.

•

WM-cortisol relations were found for mean diffusivity and hyperintensity volume but not fractional anisotropy.

•

Higher cortisol in response to cognitive stressor denoted lower WM integrity.

Experience and opinions on post-graduate dementia training in the UK: a survey of selected consultant geriatricians

INTRODUCTION

people with dementia are more likely to come into contact with a geriatrician than any other hospital specialty. Whilst it is known that there are some geriatricians with a special interest in dementia, it is unclear how this group of clinicians gained experience, and what their opinions are on current training.

METHODS

we obtained a list of geriatricians known to have an interest in dementia care (known as dementia champions) from the British Geriatric Society Dementia and Similar Disorders Special Interest Group. We contacted 100 'dementia champions' with an invitation to respond to a questionnaire relating to their role, experience and opinions on current training in dementia within geriatric medicine.

RESULTS

fifty-five geriatricians responded. Ninety-one per cent were consultant physicians, and 71% were not involved in outpatient diagnostic services. Fifty-six per cent reported that their experience was via clinical attachments with old age psychiatry, and 47% regarded themselves as 'self-taught'. The majority felt that current training was inadequate with a need for more structure and time spent on attachments, less geographical variation, more training at undergraduate level and throughout other specialties and better collaboration with psychiatry.

DISCUSSION

this is the first survey of the views of geriatricians leading on dementia care in acute hospitals within the UK. It gives a useful insight into how they have gained their own experience, and their opinions on how training may be improved. Equipped with the right training and expertise in diagnosis and management of dementia perhaps geriatricians may feel more confident in taking a lead in dementia care.

Specialty experience in geriatric medicine is associated with a small increase in knowledge of delirium

Background: delirium is underdiagnosed and undertreated. Understanding of delirium among doctors in medical and ICU settings has previously been shown to be low. We hypothesised that junior doctors who had gained experience in geriatrics, neurology or psychiatry may have an increased knowledge of delirium.

Methods: we used data from a large multi-centre study of junior doctors conducted between December 2006 and January 2007 which is, to date, the largest survey of understanding of delirium among junior doctors. The original survey used a questionnaire within which certain key items led to a correct or incorrect answer. Total correct answers were recorded giving a maximum total knowledge score of 17 for each participant. The relationship between total knowledge score achieved on the questionnaire and time since qualification; specialty experience in geriatric medicine, psychiatry and/or neurology and self-reported experience with the Confusion Assessment Method (independent variables) were modelled using linear regression.

Results: around half (53.2%; 399 of 750) of those surveyed stated that they had experience in geriatric medicine. In contrast only 4.1 and 8.0% of respondents had experience in psychiatry and neurology, respectively. Experience in geriatric medicine was significantly associated with a modest increase in correct answers (4.7 versus 4.3 points, P = 0.020). No other variables were significantly associated with better scores.

Conclusion: experience in geriatric medicine leads to a small improvement in understanding of delirium among junior doctors.

Increased skeletal muscle 11βHSD1 mRNA is associated with lower muscle strength in ageing

Background

Sarcopenia, the loss of muscle mass and function with age, is associated with increased morbidity and mortality. Current understanding of the underlying mechanisms is limited. Glucocorticoids (GC) in excess cause muscle weakness and atrophy. We hypothesized that GC may contribute to sarcopenia through elevated circulating levels or increased glucocorticoid receptor (GR) signaling by increased expression of either GR or the GC-amplifying enzyme 11beta-hydroxysteroid dehydrogenase type 1 (11βHSD1) in muscle.

Methods

There were 82 participants; group 1 comprised 33 older men (mean age 70.2years, SD 4.4) and 19 younger men (22.2years, 1.7) and group 2 comprised 16 older men (79.1years, 3.4) and 14 older women (80.1years, 3.7). We measured muscle strength, mid-thigh cross-sectional area, fasting morning plasma cortisol, quadriceps muscle GR and 11βHSD1 mRNA, and urinary glucocorticoid metabolites. Data were analysed using multiple linear regression adjusting for age, gender and body size.

Results

Muscle strength and size were not associated with plasma cortisol, total urinary glucocorticoids or the ratio of urinary 5β-tetrahydrocortisol +5α-tetrahydrocortisol to tetrahydrocortisone (an index of systemic 11βHSD activity). Muscle strength was associated with 11βHSD1 mRNA levels (β -0.35, p = 0.04), but GR mRNA levels were not significantly associated with muscle strength or size.

Conclusion

Although circulating levels of GC are not associated with muscle strength or size in either gender, increased cortisol generation within muscle by 11βHSD1 may contribute to loss of muscle strength with age, a key component of sarcopenia. Inhibition of 11βHSD1 may have therapeutic potential in sarcopenia.

Delirium and cerebrospinal fluid S100B in hip fracture patients: a preliminary study

OBJECTIVES

Delirium is associated with an increased risk of long-term cognitive decline, suggesting the possibility of concurrent central nervous system (CNS) injury. S100B is a putative biomarker of CNS injury and elevated serum levels in delirium have been reported. Here we hypothesize that delirium is associated with raised concentrations of cerebrospinal fluid (CSF) S100B.

METHODS

Forty-five patients with hip fracture aged over 60 and awaiting surgery under spinal anesthesia were assessed for delirium pre- and post-operatively. CSF S100B levels were measured in samples collected at the onset of surgery.

RESULTS

Participants with pre-operative delirium (N = 8) had elevated Log10 CSF S100B (mean: -0.156; SD: 0.238) compared with those without delirium (mean: -0.306; SD: 0.162), Student's t-test t = 2.18, df = 43, p = 0.035.

CONCLUSIONS

This study provides preliminary evidence of elevated CSF S100B in current delirium, consistent with findings in serum and with other studies showing elevated S100B in the presence of diverse forms of CNS injury.

Neck muscle cross-sectional area, brain volume and cognition in healthy older men: a cohort study

Background

Two important consequences of the normal ageing process are sarcopenia (the age-related loss of muscle mass and function) and age-related cognitive decline. Existing data support positive relationships between muscle function, cognition and brain structure. However, studies investigating these relationships at older ages are lacking and rarely include a measure of muscle size. Here we test whether neck muscle size is positively associated with cognition and brain structure in older men.

Methods

We studied 51 healthy older men with mean age 73.8 (sd 1.5) years. Neck muscle cross-sectional area (CSA) was measured from T1-weighted MR-brain scans using a validated technique. We measured multiple cognitive domains including verbal and visuospatial memory, executive functioning and estimated prior cognitive ability. Whole brain, ventricular, hippocampal and cerebellar volumes were measured with MRI. General linear models (ANCOVA) were performed.

Results

Larger neck muscle CSA was associated with less whole brain atrophy (t = 2.86, p = 0.01, partial eta squared 17%). Neck muscle CSA was not associated with other neuroimaging variables or current cognitive ability. Smaller neck muscle CSA was unexpectedly associated with higher prior cognition (t = −2.12, p < 0.05, partial eta squared 10%).

Conclusions

In healthy older men, preservation of whole brain volume (i.e. less atrophy) is associated with larger muscle size. Longitudinal ageing studies are now required to investigate these relationships further.

Delirium is a strong risk factor for dementia in the oldest-old: a population-based cohort study

Recent studies suggest that delirium is associated with risk of dementia and also acceleration of decline in existing dementia. However, previous studies may have been confounded by incomplete ascertainment of cognitive status at baseline. Herein, we used a true population sample to determine if delirium is a risk factor for incident dementia and cognitive decline. We also examined the effect of delirium at the pathological level by determining associations between dementia and neuropathological markers of dementia in patients with and without a history of delirium. The Vantaa 85+ study examined 553 individuals (92% of those eligible) aged ≥85 years at baseline, 3, 5, 8 and 10 years. Brain autopsy was performed in 52%. Fixed and random-effects regression models were used to assess associations between (i) delirium and incident dementia and (ii) decline in Mini-Mental State Examination scores in the whole group. The relationship between dementia and common neuropathological markers (Alzheimer-type, infarcts and Lewy-body) was modelled, stratified by history of delirium. Delirium increased the risk of incident dementia (odds ratio 8.7, 95% confidence interval 2.1-35). Delirium was also associated with worsening dementia severity (odds ratio 3.1, 95% confidence interval 1.5-6.3) as well as deterioration in global function score (odds ratio 2.8, 95% confidence interval 1.4-5.5). In the whole study population, delirium was associated with loss of 1.0 more Mini-Mental State Examination points per year (95% confidence interval 0.11-1.89) than those with no history of delirium. In individuals with dementia and no history of delirium (n = 232), all pathologies were significantly associated with dementia. However, in individuals with delirium and dementia (n = 58), no relationship between dementia and these markers was found. For example, higher Braak stage was associated with dementia when no history of delirium (odds ratio 2.0, 95% confidence interval 1.1-3.5, P = 0.02), but in those with a history of delirium, there was no significant relationship (odds ratio 1.2, 95% confidence interval 0.2-6.7, P = 0.85). This trend for odds ratios to be closer to unity in the delirium and dementia group was observed for neuritic amyloid, apolipoprotein ε status, presence of infarcts, α-synucleinopathy and neuronal loss in substantia nigra. These findings are the first to demonstrate in a true population study that delirium is a strong risk factor for incident dementia and cognitive decline in the oldest-old. However, in this study, the relationship did not appear to be mediated by classical neuropathologies associated with dementia.

Detecting deficits of sustained visual attention in delirium

BACKGROUND

Inattention is a core clinical feature of delirium and yet the particular aspects of attentional impairment associated with this feature are poorly understood. Objective methods for assessing inattention are also lacking. A new set of computerised tests of attentional deficits designed for use in patients with delirium have been developed. Test performances in patients with delirium, dementia and cognitively normal controls are compared.

METHODS

Eight novel tasks measuring sustained visual attention were administered to 20 older patients with delirium using the Edinburgh Delirium Test Box, a purpose built, computerised neuropsychological testing device. Comparison groups of 18 patients with Alzheimer's dementia and 20 cognitively normal patients of similar age were also assessed. Delirium was diagnosed using the Confusion Assessment Method. General cognitive impairment was measured using the Mini-Mental State Examination.

RESULTS

Patients with delirium had significantly lower scores than both comparison groups on all sustained attention tasks (p values from 0.003 to <0.001). Performance of the dementia patients generally did not differ from the cognitively normal group. Receiver operating characteristic analyses indicated that all tasks showed good or excellent accuracy for discriminating between delirium and dementia (AUC values 0.80-0.94), and between delirium and cognitively normal (AUC values 0.89-0.99) patients.

CONCLUSIONS

Patients with delirium showed marked deficits in sustained visual attention, as measured by objective neuropsychological testing. These attentional deficits were mainly mild or absent in patients with dementia and in cognitively normal controls. Objective testing of sustained visual attention has promising utility in detecting delirium, and in discriminating delirium from dementia.

11β-hydroxysteroid dehydrogenase type 1, brain atrophy and cognitive decline

Excess cortisol levels are linked with brain atrophy and cognitive decline in older people. 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) potently amplifies intracellular glucocorticoid action by converting inert cortisone to active cortisol, but any causal importance in brain aging is unexplored. We tested the hypotheses that higher systemic 11β-HSD1 activity predicts brain atrophy and cognitive decline in older men. In a longitudinal study of 41 men (65-70 years old at baseline) we measured baseline systemic 11β-HSD1 activity, the urinary 5alpha- and 5beta-tetrahydrocortisol to tetrahydrocortisone ratio (ratio of tetrahydrometabolites of cortisol (THFs)/ratio of tetrahydrometabolites of cortisol (THE)), and assessed change in brain atrophy, white matter lesions and cognitive function over 6 years. Baseline THFs/THE correlated negatively with baseline hippocampal volumes (left: r = -0.37; right: r = -0.34; p < 0.05) and positively with ventricular volumes (r = 0.43, p = 0.006) and periventricular white matter lesions (rho = 0.31, p = 0.047). Importantly, baseline THFs/THE but not cortisol predicted increase in ventricular volumes (r = 0.33, p = 0.037) and decline in processing speed (r = -0.55, p = 0.0002) over 6 years. The predictive link between systemic 11β-HSD1 activity and progressive brain atrophy and cognitive decline suggests 11β-HSD1 inhibition as a plausible therapy for brain aging.

Quantifying the effects of normal ageing on white matter structure using unsupervised tract shape modelling

Quantitative tractography may provide insights into regional heterogeneity of changes in white matter structure in normal ageing. Here we examine how brain atrophy and white matter lesions affect correlations between tract shape, tract integrity and age in a range of frontal and non-frontal tracts in 90 non-demented subjects aged over 65 years using an enhanced version of probabilistic neighbourhood tractography. This novel method for automatic single seed point placement employs unsupervised learning and streamline selection to provide reliable and accurate tract segmentation, whilst also indicating how the shape of an individual tract compares to that of a predefined reference tract. There were significant negative correlations between tract shape similarity to reference tracts derived from a young brain white matter atlas and age in genu and splenium of corpus callosum. Controlling for intracranial and lateral ventricle volume, the latter of which increased significantly with age, attenuated these correlations by 40% and 84%, respectively, indicating that this age-related change in callosal tract topology is significantly mediated by global atrophy and ventricular enlargement. In accordance with the "frontal ageing" hypothesis, there was a significant positive correlation between mean diffusivity (D) and age, and a significant negative correlation between fractional anisotropy (FA) and age in corpus callosum genu; correlations not seen in splenium. Significant positive correlations were also observed between D and age in bilateral cingulum cingulate gyri, uncinate fasciculi and right corticospinal tract. This pattern of correlations was not, however, reproduced when those subjects with significant white matter lesion load were analyzed separately from those without. These data therefore suggest that brain atrophy and white matter lesions play a significant role in driving regional patterns of age-related changes in white matter tract shape and integrity.

Enlarged perivascular spaces on MRI are a feature of cerebral small vessel disease

BACKGROUND AND PURPOSE

Enlarged perivascular spaces in the brain are common but generally overlooked and of uncertain pathophysiology. They may reflect underlying cerebral small vessel disease. We determined whether enlarged perivascular spaces were associated with lacunar stroke subtype and white matter hyperintensities, markers of established small vessel disease.

MATERIALS AND METHODS

We prospectively recruited patients with acute ischemic lacunar or cortical stroke. Age-matched nonstroke control subjects were also recruited. We rated basal ganglia and centrum semiovale enlarged perivascular spaces 0 to 4 (0=none, 4=>40) on T2-weighted MRI and white matter hyperintensities. We compared enlarged perivascular spaces between stroke subtypes and control subjects and assessed associations with vascular risk factors and white matter hyperintensities.

RESULTS

We recruited 350 patients; 129 lacunar, 124 cortical stroke, and 97 age-matched control subjects. Adjusting for vascular risk factors and white matter hyperintensities, total enlarged perivascular spaces were associated with lacunar stroke subtype (P=0.04) in the acute stroke group (n=253); basal ganglia enlarged perivascular spaces were associated with lacunar stroke subtype (P=0.003), deep (P=0.02) and periventricular white matter hyperintensities (P=0.01); in all 350 subjects, total enlarged perivascular spaces were associated with deep (P<0.001) and periventricular (P<0.001) white matter hyperintensities.

CONCLUSIONS

Although prevalent in patients with vascular risk factors and stroke, enlarged perivascular spaces are specifically associated with lacunar ischemic stroke and white matter hyperintensities. Further studies should determine the mechanism of this association while including adequate controls to account for stroke and vascular risk factors. Enlarged perivascular spaces should not be overlooked in studies of small vessel disease.

Quantitative and qualitative measures of hippocampal atrophy are not correlated in healthy older men

BACKGROUND AND PURPOSE

In neuroimaging studies of dementia and mild cognitive impairment, hippocampal atrophy (HA) is commonly assessed by qualitative ratings of hippocampal appearance, or by measuring hippocampal volumes. These estimates of HA are considered to be equivalent. However, few studies have examined their relationship, especially in healthy older individuals. We therefore examined the relationship between hippocampal qualitative atrophy scores and quantitative volumetric measurements in healthy older men.

METHODS

Ninety-seven healthy community-dwelling 65-70-year-old men underwent magnetic resonance imaging scanning. Hippocampal volumes were measured and adjusted for intracranial size. A validated 4-point visual rating scale was used to assess hippocampal atrophy.

RESULTS

There was a wide range of unadjusted hippocampal volumes among subjects (right: 2,582 to 5,196 mm(3)[mean 3,626 mm(3); SD 465.5 mm(3)] and left: 2,111 to 4,580 mm(3)[mean 3,501 mm(3); SD 439.5 mm(3)]), which was maintained following adjustment for intracranial size. However, only 9% of subjects were rated as having moderate or severe HA. Qualitative and quantitative measures were not significantly correlated (left hippocampus: rho = .07, P= .52; right hippocampus: rho = .10, P= .34).

CONCLUSIONS

This study shows that qualitative and quantitative indices of hippocampal atrophy in healthy older men are not equivalent. Small hippocampal volumes do not necessarily equate to hippocampal atrophy.

Delirium and long-term cognitive impairment

Delirium is a severe, acute neuropsychiatric syndrome that is highly prevalent in acute hospital populations. Delirium has noticeable effects on length of hospitalization, cost of care, mortality and morbidity. In addition to these well-established adverse consequences, there is increasing evidence linking delirium and a higher risk of long-term cognitive impairment (LTCI), including dementia. A prior review (Jackson, Gordon, Hart, Hopkins, & Ely, 2004), in which nine studies (total N = 1,885, years 1989-2003) were considered, concluded that there was evidence for an association between delirium and LTCI. Here we provide a review of studies published since Jackson's review. We included nine reports, with a total of 2,025 patients. The studies show diverse sample sizes, methodologies, designs and patient populations. However, taken together, the results of these new studies broadly confirm that there is a link between delirium and LTCI. We go on to discuss putative mechanisms and explanations. These include (1) delirium as a marker of chronic progressive pathology, but unrelated to any progression, (2) delirium as a consequence of acute brain damage which is also responsible for a 'single hit' or triggering of active processes causing LTCI, (3) delirium itself as a cause of LTCI, and (4) drug treatment of delirium or other conditions as a cause of LTCI. We conclude with suggestions for future research.

Diabetes and cognitive decline: are steroids the missing link?

Although elevated cortisol levels may be found in diabetes, cortisol's role in diabetes-associated cognitive impairment is unclear. A recent study (Stranahan et al., 2008) shows that reducing glucocorticoid levels in rodent diabetes models prevents cognitive deficits and enhances neurogenesis and synaptic plasticity. The clinical relevance of these intriguing findings remains undetermined.

The role of research training during higher medical education in the promotion of academic medicine in the UK

OBJECTIVES

To examine the research activities and perceived barriers to research among higher specialist trainees in geriatric medicine and to show how trainees active in research might have a role in assisting their peers in getting started in research.

DESIGN

Cross-sectional questionnaire survey on research activities, attitudes to doing research and perceived difficulties in doing research.

SETTING AND PARTICIPANTS

Trainee members of the British Geriatrics Society (BGS) in the UK.

RESULTS

A total of 122 responses (30% response rate) were received after a single mailing and a follow-up questionnaire to trainees attending the BGS national conference. Although 64% (67/104) of respondents would like to undertake a period of research, many perceived barriers preventing them from planning, funding and executing a research project. Among those who had not undertaken research, the majority (70%, 42/60) indicated that they have no clear idea of a topic to research, 64% (39/61) did not know how to develop an idea and 62% (38/61) indicated that they did not know how to get funding. Trainees motivated to do research were faced with particular difficulties with regards to funding and selection of a project topic.

CONCLUSIONS

One useful method would be systematically to provide basic information to trainees on how to enter into the early stages of research. This would help to overcome some of the unnecessary uncertainty that many trainees keen to do research seem to have.

Smaller left anterior cingulate cortex volumes are associated with impaired hypothalamic-pituitary-adrenal axis regulation in healthy elderly men

CONTEXT

Studies in animals suggest that the limbic prefrontal cortex, including the anterior cingulate cortex, is involved in regulation of the hypothalamic-pituitary-adrenal (HPA) axis, but human data are lacking.

OBJECTIVE

This study tested the hypothesis that smaller anterior cingulate cortex volumes are associated with HPA axis dysregulation in healthy older men.

DESIGN AND PARTICIPANTS

Comparison was made of volumes of bilateral anterior cingulate cortex, hippocampus, and superior frontal gyrus (control region) volumes in two groups of 10 healthy men, aged 65-70 yr, who showed nonsuppression or suppression of cortisol levels in response to low dose (250 microg) dexamethasone. Analysis of brain volumes was performed blind to the cortisol levels.

SETTING

This study was performed at a tertiary care clinical research center.

RESULTS

Nonsuppressors had significantly smaller left anterior cingulate cortex volumes than suppressors (5757 vs. 7817 mm(3); P = 0.01). Right anterior cingulate cortex, bilateral hippocampus, and bilateral superior frontal gyrus volumes were not significantly different between nonsuppressors and suppressors.

CONCLUSIONS

Smaller left anterior cingulate cortex volumes may be associated with HPA axis dysregulation in humans. These results substantiate evidence from animal studies indicating an important role for the anterior cingulate cortex in suprahypothalamic feedback regulation of the HPA axis. The results also have implications for disorders in which HPA axis dysregulation and abnormalities of the anterior cingulate cortex are frequently observed, such as depression and Alzheimer's disease.

Plasma cortisol levels, brain volumes and cognition in healthy elderly men

PURPOSE

In ageing animals, exposure to chronic high levels of glucocorticoids is associated with cognitive impairment and hippocampal atrophy. However, there are few studies examining relationships among glucocorticoids, brain volumes and cognitive function in healthy older humans. This study examined the hypotheses that higher plasma cortisol levels and altered sensitivity to glucocorticoids are associated with worse cognition and more brain atrophy in elderly men.

MATERIALS AND METHODS

Ninety-seven healthy men aged 65-70 had plasma cortisol measured at 09:00, 14:30 h, and post-dexamethasone (0.25mg, 09:00 h), and had dermal sensitivity to glucocorticoids measured. They also underwent cognitive testing, with scores adjusted for estimated prior mental ability, and had MRI measurements of intracranial area (a validated estimate of intracranial capacity), and hippocampus, temporal lobe and frontal lobe volumes.

RESULTS

Plasma cortisol levels at 09:00 h were significantly and negatively correlated with a summary General Cognitive Factor accounting for 51% of the variance of cognitive function (rho=-0.22, p=0.035), and specific cognitive tests: delayed paragraph recall (rho=-0.28, p=0.036) and processing speed (rho=-0.23, p=0.026). Regional brain volumes adjusted for intracranial area generally did not correlate with cortisol levels. Tissue glucocorticoid sensitivity did not correlate with any measure of cognition or brain volume.

CONCLUSIONS

In healthy older men, higher plasma cortisol levels are associated with worse ageing-related overall cognitive change but not ageing-related brain atrophy.

Size of the neocerebellar vermis is associated with cognition in healthy elderly men

Cerebellar volumes show small positive correlations with cognitive ability in young adults, but no studies have examined this relationship in older adults. Furthermore, no studies have examined relationships between sizes of subareas of the cerebellum and cognitive ability. We hypothesized that size of the two areas of the neocerebellar vermis would correlate with a battery of eight cognitive tests in 50 men aged 65-70. Size of the neocerebellar areas of the vermis correlated positively with several cognitive tests (r's=.29-.37, p<.05), whilst sizes of other parts of the vermis did not correlate with any cognitive tests. Total cerebellar volumes correlated significantly with a test of nonverbal reasoning (r=.030, p=.42). These findings suggest a specific association of neocerebellar vermis size with variations in cognitive ability in older adults.