Are stroke survivors with delirium at higher risk of post-stroke dementia? Current evidence and future directions

Delirium in acute stroke is associated with increased cognitive and psychiatric symptoms over time: The Nor-COAST study

BACKGROUND

Delirium, an acute and fluctuating mental disturbance of attention, cognition, and consciousness, commonly occurs in acute stroke. Research on long-term outcomes of stroke patients experiencing delirium is limited, especially regarding cognitive and psychiatric symptoms.

METHODS

As part of the Nor-COAST study, 373 patients were screened for delirium using the Confusion Assessment Method (CAM) in the acute phase of stroke. Patients were included in the mixed-model linear regression analyses if they had available data from the follow-ups at three, 18 or 36 months, totaling 334 (44.6 % women, mean (SD) age: 72.1 (12.5) years, 17 (5.1 %) diagnosed with delirium). Global cognition was measured using the Montreal Cognitive Assessment (MoCA). Psychiatric symptoms were measured using the Hospital Anxiety and Depression Scale (HADS) and the Neuropsychiatric Inventory-Questionnaire (NPI-Q).

RESULTS

At three months, delirium was associated with a higher NPI-Q score (Mean (SD) 2.9 (3.6) vs 1.4 (2.2)). At 18 and 36 months, delirium was associated with a lower MoCA score (Mean (SD) 19.7 (6.6) vs 24.3 (5.0), and 20.6 (7.6) vs 24.6 (4.8)), higher HADS anxiety symptoms (5.0 (4.3) vs 3.3 (3.3), and 5.9 (4.1) vs 3.4 (3.6)), higher HADS depression symptoms (7.2 (4.7) vs 3.4 (3.3), and 6.6 (5.1) vs 3.7 (3.7)), and higher NPI-Q score (2.4 (4.4) vs 1.7 (2.3), 2.6 (4.5) vs 1.0 (1.9)). Delirium significantly predicted the psychiatric symptoms hallucinations and agitation.

CONCLUSIONS

Patients with delirium in the acute phase of stroke may be particularly vulnerable to developing cognitive and psychiatric symptoms in the chronic phase.

ICU admission Braden score independently predicts delirium in critically ill patients with ischemic stroke

BACKGROUND

Delirium is a common and severe complication in intensive care unit (ICU) patients with acute ischemic stroke, exacerbating cognitive and physical impairments. It prolongs hospitalization, increases healthcare costs, and raises mortality risk. Early prediction is crucial because it facilitates prompt interventions that could possibly reverse or alleviate the detrimental consequences of delirium. Braden scores, traditionally used to assess pressure injury risk, could also signal frailty, providing an early warning of delirium and aiding in prompt and effective patient management.

OBJECTIVE

To examine the association between the Braden score and delirium.

METHODS

A retrospective analysis of adult ischemic stroke patients in the ICU of a tertiary academic medical center in Boston from 2008 to 2019 was performed. Braden scores were obtained on admission for each patient. Delirium, the primary study outcome, was assessed using the Confusion Assessment Method for Intensive Care Unit and a review of nursing notes. The association between Braden score and delirium was determined using Cox proportional hazards modeling, with hazard ratios (HR) and 95% confidence intervals (CI) calculated.

RESULTS

The study included 3,680 patients with a median age of 72 years, of whom 1,798 were women (48.9 %). The median Braden score at ICU admission was 15 (interquartile range 13-17). After adjustment for demographics, laboratory tests, severity of illness, and comorbidities, the Braden score was inversely associated with the risk of delirium (adjusted HR: 0.94, 95 % CI: 0.92-0.96, P < 0.001).

CONCLUSIONS

The Braden score may serve as a convenient and simple screening tool to identify the risk of delirium in ICU patients with ischemic stroke.

IMPLICATION FOR CLINICAL PRACTICE

The use of the Braden score as a predictor of delirium in ischemic stroke patients in the ICU allows early identification of high-risk patients. This facilitates timely intervention, thereby improving patient outcomes and potentially reducing healthcare costs.

Associations of Delirium to Posthospital Outcomes After Acute Stroke: A Scoping Review

ABSTRACT

Background: Delirium is a common and distressing manifestation of acute brain dysfunction that is associated with poor outcomes in various critically ill patient populations. Although patients with acute stroke experience delirium, understanding of delirium in this population is limited. The purpose of this scoping review is to describe existing evidence about delirium and associations with posthospital outcomes after acute stroke. Methods: Arksey and O'Malley's 5-stage framework was used to perform a scoping review. PubMed, CINAHL, and EMBASE electronic databases were searched. Outcome domains of interest included mortality, cognitive function, physical function, mental health, and quality of life. Full-text, peer-reviewed articles with adult stroke sample populations (acute ischemic stroke, intracerebral hemorrhage, subarachnoid hemorrhage) were included. Results: Nineteen articles, involving 5611 unique patients, were included. Most sample populations included patients with either acute ischemic stroke or intracerebral hemorrhage. Heterogeneous research aims, methods, and outcome measures limit the ability to compare specific findings across studies. However, included studies suggest higher mortality at 12 months, worse cognition, and greater functional impairment in patients who have experienced acute stroke and delirium. Limited information regarding associations of delirium with posthospital mental health outcomes and quality of life precluded the ability to analyze these relationships and warrants further investigation. Conclusion: This review suggests concerning findings about associations of delirium to posthospital outcomes after acute stroke. Better characterization of delirium after acute stroke and analysis of its impact on long-term outcomes are needed.

Cognitive, Functional, and Mortality Outcomes of Attenuated Delirium Syndrome in Stroke Survivors

OBJECTIVES

There is a knowledge gap on the prognostic significance of subsyndromes of delirium. We describe the association of poststroke attenuated delirium syndrome (ADS) with cognitive, functional, and mortality outcomes at 3 months.

METHODS

A longitudinal observational study in which repeated assessments for delirium symptoms were conducted in the first week of stroke using the confusion assessment method. Attenuated delirium syndrome was characterized in survivors who were free of the full delirium syndrome but had ≥2 core features of delirium. Baseline and follow-up assessments were conducted using the Mini-Mental State Examination (MMSE), 10-word list learning and delayed recall test, Animal naming test, and Barthel index.

RESULTS

Among 150 participants recruited consecutively over 2 years, ADS was present in 32 (21.3%). Of 121 who were free of the full delirium syndrome, 21 (17.4%) had died by 3 months. Those who survived were more likely to be receiving treatment for systemic hypertension (88.5%, P = .007). In analyses adjusting for the effect of age, economic status, and systemic hypertension, ADS in the first week of stroke predicted cognitive decline at 3 months ([mean difference (MD) in MMSE scores = -3.8, 95% CI = -7.0 to -0.7, P = .019]). However, ADS was not associated with greater decline in activities of daily life (MD = -0.4, 95% CI = -2.8 to 2.0) or significant odds ratio (OR) of mortality (OR = 2.3, 95% CI = 0.8-6.3).

CONCLUSION

Attenuated delirium syndrome may be an important marker of cognitive impairment at 3 months poststroke. Its detection may lead to identification of stroke survivors who are likely to benefit from evidence-based preventive interventions for poststroke cognitive decline.

Microglia-mediated phagocytosis of apoptotic nuclei is impaired in the adult murine hippocampus after stroke

Following stroke, neuronal death takes place both in the infarct region and in brain areas distal to the lesion site including the hippocampus. The hippocampus is critically involved in learning and memory processes and continuously generates new neurons. Dysregulation of adult neurogenesis may be associated with cognitive decline after a stroke lesion. In particular, proliferation of precursor cells and the formation of new neurons are increased after lesion. Within the first week, many new precursor cells die during development. How dying precursors are removed from the hippocampus and to what extent phagocytosis takes place after stroke is still not clear. Here, we evaluated the effect of a prefrontal stroke lesion on the phagocytic activity of microglia in the dentate gyrus (DG) of the hippocampus. Three-months-old C57BL/6J mice were injected once with the proliferation marker BrdU (250 mg/kg) 6 hr after a middle cerebral artery occlusion or sham surgery. The number of apoptotic cells and the phagocytic capacity of the microglia were evaluated by means of immunohistochemistry, confocal microscopy, and 3D-reconstructions. We found a transient but significant increase in the number of apoptotic cells in the DG early after stroke, associated with impaired removal by microglia. Interestingly, phagocytosis of newly generated precursor cells was not affected. Our study shows that a prefrontal stroke lesion affects phagocytosis of apoptotic cells in the DG, a region distal to the lesion core. Whether disturbed phagocytosis might contribute to inflammatory- and maladaptive processes including cognitive impairment following stroke needs to be further investigated.

Current view on post-stroke dementia

Dementia is one of the leading complications after stroke affecting about one third of survivors. Prevalence of post-stroke dementia (PSD) differs between studies due to variability in methodology, characteristics of included patients, type of stroke, diagnostic tools used to identify patients with dementia, or time when the assessment was performed. Patients diagnosed with PSD are at higher risk of mortality, disability, and institutionalization. Aetiology of PSD may include mixed overlapping processes such as vascular brain pathology or Alzheimer's disease. Several risk factors have been found to increase PSD incidence, involving demographics, vascular factors, stroke characteristics, abnormalities on neuroimaging, and stroke complications. However, the influence of some other factors still remains unclear. PSD may coexist with other neuropsychiatric disorders and its association with post-stroke depression seems to be the most significant. There is a strong need for further research on possible genetic, biological, and inflammatory biomarkers. Also, there are no unambiguously efficacious methods of management. Continuing to address these issues will help to find more effective interventions directly targeting prevention and treatment of PSD in the future.

Different Cognitive and Functional Outcomes in Attenuated and Full Delirium Syndromes Among Recent Stroke Survivors

BACKGROUND

Very little is known about the outcomes of poststroke delirium in relation to its symptom spectrum. We investigated the 3-months cognitive and functional outcomes of attenuated (ADS) and full delirium syndromes in Nigerian survivors of first ever stroke.

METHODS

A prospective observational study with repeated assessments conducted in the first week of stroke using the confusion assessment method. Full delirium was diagnosed according to criteria in the fifth edition of the diagnostic and statistical manual of mental disorders (DSM-V). ADS was characterised in survivors who were free of full, but had ≥two core features of, delirium. Baseline and follow-up assessments were conducted using the Mini-Mental state examination (MMSE), 10-words list learning and delayed recall test, Animal naming test and Barthel index.

RESULTS

Among 150 participants, ADS was present in 32 (21.3%), full delirium in 29 (19.3%). In linear regression analyses adjusting for age, economic status and systemic hypertension, ADS [(Mean difference (MD) = -3.8, 95% C.I = -7.0, -0.7)] and full delirium (MD = -5.6, 95% C.I = -9.0, -2.1) independently predicted poorer global cognitive functioning at follow-up. Significant declines in memory (MD = -1.9, 95% C.I = -2.8, 0.9), executive (MD = -2.2, 95% C.I = -4.1, -0.3) and physical functioning (MD = -2.8, 95% C.I = -5.5, -0.2), as well as a 4-fold increase in the independent odds (O.R) for dementia (O.R = 4.1, 95% C.I = 1.0,16.1) were also recorded in full, but not attenuated, delirium.

CONCLUSION

Attenuated and full delirium are associated with graded risk of poststroke cognitive decline. Reconsideration of poststroke delirium as a spectrum, rather than threshold-based categorical diagnosis will improve detection and prioritization of stroke survivors at increased risk of cognitive decline.

Association Between Common Infections and Incident Post-Stroke Dementia: A Cohort Study Using the Clinical Practice Research Datalink

PURPOSE

To investigate the association between common infections and post-stroke dementia in a UK population-based cohort.

MATERIALS AND METHODS

A total of 60,392 stroke survivors (51.2% male, median age 74.3 years, IQR 63.9-82.4 years) were identified using primary care records from the Clinical Practice Research Datalink (CPRD) linked to Hospital Episode Statistics (HES) with no history of dementia. Primary exposure was any GP-recorded infection (lower respiratory tract infection (LRTI), urinary tract infection (UTI) requiring antibiotics, skin and soft tissue infection requiring antibiotics) occurring after stroke. The primary outcome was incident all-cause dementia recorded in primary care records. In sensitivity analyses, we restricted to individuals with linked hospital records and expanded definitions to include ICD-10 coded hospital admissions. We used multivariable Cox regression to investigate the association between common infections and dementia occurring from 3 months to 5 years after stroke.

RESULTS

Of 60,392 stroke survivors, 20,969 (34.7%) experienced at least one infection and overall 4512 (7.5%) developed dementia during follow-up. Early dementia (3 months to 1-year post-stroke) risk was increased in those with at least one GP-recorded infection (HR 1.44, 95% CI 1.21-1.71), with stronger associations when hospitalised infections were included (HR 1.84, 95% CI 1.58-2.14). Late dementia (1-5 years) was only associated with hospitalised, but not with GP-recorded, infections.

CONCLUSION

There was evidence of an association between common infections and post-stroke dementia, strongest in the 3-12 months following stroke. Better understanding of this relationship could help inform knowledge of pathways to dementia post-stroke and targeting of preventive interventions.

Delirium Post-Stroke-Influence on Post-Stroke Dementia (Research Study-Part of the PROPOLIS Study)

BACKGROUND

Previous research confirmed association between delirium and subsequent dementia in different clinical settings, but the impact of post-stroke delirium on cognitive functioning is still under-investigated. Therefore, we aimed to assess the risk of dementia among patients with stroke and in-hospital delirium.

METHODS

A total of 750 consecutive patients admitted to the stroke unit with acute stroke or transient ischemic attacks were screened for delirium, during the first seven days after admission. At the three- and twelve-month follow-up, patients underwent cognitive evaluation. The DSM-5 definition for dementia was used. Cases with pre-stroke dementia were excluded from the analysis.

RESULTS

Out of 691 included cases, 423 (61.22%) and 451 (65.27%) underwent cognitive evaluation, three and twelve months after stroke; 121 (28.61%) and 151 (33.48%) patients were diagnosed with dementia, respectively. Six (4.96%) patients with dementia, three months post-stroke did not meet the diagnostic criteria for dementia nine months later. After twelve months, 37 (24.50%) patients were diagnosed with dementia, first time after stroke. Delirium in hospital was an independent risk factor for dementia after three months (OR = 7.267, 95%CI 2.182-24.207, p = 0.001) but not twelve months after the stroke.

CONCLUSIONS

Patients with stroke complicated by in-hospital delirium are at a higher risk for dementia at three but not twelve months post-stroke.

Delirium in patients with ischaemic and haemorrhagic stroke: findings from a scoping review

BACKGROUND

Delirium is a complex syndrome characterised by disturbances in attention and awareness, associated with alterations in cognitive functions, which can emerge in a time frame of hours or days and tend to fluctuate in severity over time. Delirium is a clinical manifestation of the brain's vulnerability and diminished resilience to insult. Stroke patients are particularly vulnerable to delirium episodes.

AIMS

The aim of this study was to map: (a) studies focused on ischaemic or haemorrhagic post-stroke delirium; (b) factors that have been investigated as being possibly associated with post-stroke delirium; and (c) outcomes that have been studied to date.

METHODS

A scoping review was performed. Medline, CINAHL, Cochrane Database of Systematic Reviews, PsycINFO and Scopus databases were searched. Eligible studies were those: (a) exploring any variable regarding delirium in patients with stroke; (b) involving adults; (c) as primary studies; (d) written in English; and (e) published before April 2017.

RESULTS

To date 25 studies have been published, mainly prospective or cohort studies. The most commonly studied predisposing factors have been the older age, gender, aetiology of the stroke and its location, and the presence of previous cognitive decline/dementia. The most studied precipitating factors to date have been pneumonia, urinary tract infections and symptoms of neglect. Functional dependence, length of inhospital stays, post-stroke cognitive impairments or dementia, short and long-term mortality have been the most studied post-stroke delirium outcomes.

CONCLUSIONS

Studies across different clinical settings, also at the international level, including more female patients and a wider range of ages should be designed in order to improve the evidence available to develop specific clinical guidelines. Standardised frameworks of research addressing the great variability of methods and measures used in the field should be established at the international level by clinicians and researchers' experts in the field.

Study on epidemiology of cognitive dysfunction after stroke in the population over the age of 45 in Inner Mongolia

OBJECTIVE

To analyze the prevalence of different degrees vascular cognitive impairment (VCI) in stroke and the characteristics of demography distribution in Inner Mongolia. In order to provide reference data and theoretical guidance for the prevention and treatment of VCI after stroke in the area.

METHODS

Stratified multi-stage random sampling was used to extract six regions of Inner Mongolia as the first sampling cluster; and then the corresponding banners (counties) were selected randomly as the secondary sampling cluster; according to the number of patient required to investigation, the corresponding number of communities was randomly selected from the secondary sampling cluster. According to the diagnostic criteria of 'Guidelines for the diagnosis and treatment of vascular cognitive impairment' and National Institute of Neurological Disorders and Stroke convened an International Workshop with support from the Association Internationale pour la Recherche et l'Enseignement en Neurosciences (NINDS-AIREN), we screened all stroke patients aged 45 or older from each community, a total of 444 patients participated in the questionnaire and various scale assessments.

RESULTS

The prevalence of VCI, vascular cognitive impairment no dementia and vascular dementia was 80.41%, 34.46% and 45.95% respectively. The prevalence of VCI in stroke was significantly different in different nationality, age and education level (P < 0.05), and there was no significant difference in gender, occupation, marital status and family structure (P > 0.05).

CONCLUSION

The prevalence of VCI after stroke was higher in Inner Mongolia, and VCI had a relatively high morbidity in old age people and person with less education in Chinese Han population.

Stroke severity predicts poststroke delirium and its association with dementia: Longitudinal observation from a low income setting

OBJECTIVE

The effect of delirium on stroke outcome has not been quantified in sub-Saharan Africa. We investigated the prevalence of delirium occurring within one week of stroke in Nigerian survivors and its association with dementia and mortality at 3months.

METHODS

Delirium was ascertained after repeated assessments within one week of stroke using the Confusion Assessment Method. Demographic and clinical characteristics, stroke severity, current and pre-morbid cognitive functioning were also assessed. Participants were then followed up for 3months using culturally-validated neuropsychological tools. Probable dementia was ascertained according to the National Institute of Neurological Disorders and Stroke (NINDS-AIREN) criteria. Associations were investigated using both binomial and multinomial logistic regression analyses and presented as odds ratios (O.R) and relative risk ratios (RRR).

RESULTS

Of 101 consenting stroke survivors, 99 had two assessments for delirium within one week of the stroke. Delirium was present in 33.3% of stroke survivors (65.6% hypoactive, 21.9% hyperactive, and 12.1% mixed type). Having a severe stroke was associated with delirium (O.R=6.2, 95% C.I=1.1-13.8) after adjusting for age, gender, education and economic status, lifestyle factors, multimorbidities and laterality. At follow-up, those with severe stroke had a stronger association between delirium and dementia (RRR=4.3, 95% C.I=1.2-15.6) or death (RRR=3.7, 95% C.I=1.1-12.1).

CONCLUSION

Delirium, in this sub-Saharan African sample, was already present in about one-third of survivors within one week of stroke. Survivors of severe stroke are at higher risk of delirium and its complications, and could be important target for delirium preventive interventions.