Cumulative illness and neuropsychological decline in hospitalized geriatric patients

The Internet of Things in Geriatric Healthcare

There is a significant increase in the geriatric population across the globe. With the increase in the number of geriatric people and their associated health issues, the need for larger healthcare resources is inevitable. Because of this, healthcare service-providing industries are facing a severe challenge. However, technological advancement in recent years has enabled researchers to develop intelligent devices to deal with the scarcity of healthcare resources. In this regard, the Internet of things (IoT) technology has been a boon for healthcare services industries. It not only allows the monitoring of the health parameters of geriatric patients from a remote location but also lets them live an independent life in a cost-efficient way. The current paper provides up-to-date comprehensive knowledge of IoT-based technologies for geriatric healthcare applications. The study also discusses the current trends, issues, challenges, and future scope of research in the area of geriatric healthcare using IoT technology. Information provided in this paper will be helpful to develop futuristic solutions and provide efficient cost-effective healthcare services to the needy.

A Possible Association Between Executive Dysfunction and Frailty in Patients With Neurocognitive Disorders

Frailty is an age-related dynamic status, characterized by a reduced resistance to stressors due to the cumulative decline of multiple physiological systems. Several researches have highlighted a relationship between physical frailty and cognitive decline; however, the role of specific cognitive domains has not been deeply clarified yet. Current studies have hypothesized that physical frailty and neuropsychological deficits may share systemic inflammation and increased oxidative stress in different neurodegenerative disorders, such as Alzheimer’s and Parkinson’s disease. However, the role of the executive dysfunction should be investigated in a more detailed way using a multidimensional approach. With this aim, we conducted a review of the literature on the few experimental articles published to discuss the existence of a relationship between frailty and cognitive impairment in neurocognitive disorders, particularly focusing on the domain of executive dysfunction. The data suggest that physical frailty and cognitive decline, especially executive dysfunction, are two aspects strongly linked in mild and major neurocognitive disorders due to Alzheimer’s and Parkinson’s disease. In light of this, a new framework linking aging, cognitive decline, and neurodegenerative diseases is needed. In order to analyze the effects that aging processes have on neural decline and neurocognitive disease, and to identify relevant groups of users and patients, future longitudinal studies should adopt a multidimensional approach, in the field of primary prevention and in the continuum from mild to major neurocognitive disorder.

Multimorbidity, Function, and Cognition in Aging

Multimorbidity is a global health challenge. Here, we define multimorbidity, describe ways multimorbidity is measured, discuss the prevalence of multimorbidity and how it differs across different populations, examine mechanisms of disease and disability, and discuss the effects of multimorbidity on outcomes such as survival and function.

Long-term Associations Between Physical Frailty and Performance in Specific Cognitive Domains

OBJECTIVES

No longitudinal epidemiological research has reported associations between physical frailty and performance in specific cognitive domains. Our aim was to investigate whether such associations existed in the absence of accompanying neurodegenerative disorders such as mild cognitive impairment (MCI) and dementia.

METHOD

We addressed this issue in a population-based sample of 896 adults aged 70 years and older over 4 waves of data covering a 12-year period. Physical frailty was assessed and a cognitive battery included measures of processing speed, verbal fluency, face and word recognition, episodic memory and simple and choice reaction time (RT).

RESULTS

Latent growth models showed frailty was associated with poorer baseline performance in processing speed, verbal fluency, simple and choice RT, and choice intraindividual RT variability. However, no significant effects of frailty on slopes of cognition were observed, suggesting that frailty was not associated with cognitive decline. Importantly, when the models took possible dementia into account, significant effects were retained suggesting that differences were not associated with dementia-related neurodegenerative disorders.

DISCUSSION

The findings suggest that frailty-related cognitive deficits may exist independently of mechanisms underpinning neurodegenerative disorders such as MCI and dementia. If confirmed, this finding suggests a new avenue for preventative and therapeutic interventions in clinical and public health contexts for older adults.

Association Between Critical Care Admissions and Cognitive Trajectories in Older Adults

OBJECTIVES

Patients requiring admission to an ICU may subsequently experience cognitive decline. Our objective was to investigate longitudinal cognitive trajectories in older adults hospitalized in ICUs. We hypothesized that individuals hospitalized for critical illness develop greater cognitive decline compared with those who do not require ICU admission.

DESIGN

A retrospective cohort study using prospectively collected cognitive scores of participants enrolled in the Mayo Clinic Study of Aging and ICU admissions retrospectively ascertained from electronic medical records. A covariate-adjusted linear mixed effects model with random intercepts and slopes assessed the relationship between ICU admissions and the slope of global cognitive z scores and domains scores (memory, attention/executive, visuospatial, and language).

SETTING

ICU admissions and cognitive scores in the Mayo Clinic Study of Aging from October 1, 2004, to September 11, 2017.

PATIENTS

Nondemented participants age 50 through 91 at enrollment in the Mayo Clinic Study of Aging with an initial cognitive assessment and at least one follow-up visit.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 3,673 participants, 372 had at least one ICU admission with median (25-75th percentile) follow-up after first ICU admission of 2.5 years (1.2-4.4 yr). For global cognitive z score, admission to an ICU was associated with greater decline in scores over time compared with participants not requiring ICU admission (difference in annual slope = -0.028; 95% CI, -0.044 to -0.012; p < 0.001). ICU admission was associated with greater declines in memory (-0.029; 95% CI, -0.047 to -0.011; p = 0.002), attention/executive (-0.020; 95% CI, -0.037 to -0.004; p = 0.016), and visuospatial (-0.013; 95% CI, -0.026 to -0.001; p = 0.041) domains. ICU admissions with delirium were associated with greater declines in memory (interaction p = 0.006) and language (interaction p = 0.002) domains than ICU admissions without delirium.

CONCLUSIONS

In older adults, ICU admission was associated with greater long-term cognitive decline compared with patients without ICU admission. These findings were more pronounced in those who develop delirium while in the ICU.

The effect of parathyroidectomy on patients' symptoms in tertiary hyperparathyroidism

BACKGROUND

The efficacy of parathyroidectomy for primary and secondary hyperparathyroidism is well-established but evidence in tertiary hyperparathyroidism is lacking. We examined parathyroidectomy's effect in tertiary hyperparathyroidism.

METHODS

Patients with tertiary hyperparathyroidism who underwent parathyroidectomy were followed up for 12 months. A modification of the 13-item parathyroid symptoms list developed by Pasieka was administered at 0, 1, 3, 6, and 12 months post-surgery. We also examined if preoperative factors would predict symptom improvement post-surgery.

RESULTS

Ninety-one patients were included. Survey response rates at 1, 3, 6, and 12 months post-surgery were 97.8%, 90.1%, 82.4%, and 80.2%, respectively. Mean preoperative Pasieka parathyroid score (PSS) was 6.3 ± 2.7. At first month, PSS decreased to 2.9 ± 2.0 (P < .001) and was sustained at 3, 6, and 12 months (2.7 ± 2.1, P < .001, 2.3 ± 1.6, P < .001 and 3.4 ± 2.5, P < .001). The degree of PSS reduction at 1-month post-parathyroidectomy correlated strongly with preoperative symptom severity (Pearson's coefficient: 0.690, P < .001).

CONCLUSIONS

Parathyroid symptoms unequivocally improve post-parathyroidectomy. The greatest degree of improvement was observed in early postoperative period up to 6 months.

Neuropsychological Correlates of Pre-Frailty in Neurocognitive Disorders: A Possible Role for Metacognitive Dysfunction and Mood Changes

Background

Recent studies have suggested that cognitive functions in patients with neurocognitive disorders have a significant role in the pathogenic mechanisms of frailty. Although pre-frailty is considered an intermediate, preclinical state, epidemiological research has begun to dislodge cognition and frailty into their specific subcomponents to understand the relationship among them. We aim to analyse the possible association between pre-frailty and neuropsychological variables to outline which factors can contribute to minor and major neurocognitive disorders.

Methods

60 subjects complaining of different cognitive deficits underwent a deep-in-wide frailty and neuropsychological assessment. We conducted three multiple linear regression analyses adjusted for a combination of demographic measures and involving several neuropsychological–behavioural parameters selected by the literature on physical frailty.

Results

We found a significant association between frailty—as measured by the multidimensional prognostic index (MPI)—and action monitoring and monetary gain (cognitive domain), depression and disinhibition (behavioural domain). Moreover, an association between MPI and impaired awareness for instrumental activities disabilities exists.

Conclusion

We propose a novel framework for understanding frailty associated with metacognitive–executive dysfunction.

Physical frailty in late-life depression is associated with deficits in speed-dependent executive functions

OBJECTIVE

The aim of this study was to examine the association between physical frailty and neurocognitive performance in late-life depression (LLD).

METHODS

Cross-sectional design using baseline data from a treatment study of late-life depression was used in this study. Individuals aged 60 years and older were diagnosed with major depressive disorder at time of assessment (N = 173). All participants received clinical assessment of depression and completed neuropsychological testing during a depressive episode. Physical frailty was assessed using an adaptation of the FRAIL scale. Neuropsychological domains were derived from a factor analysis that yielded three factors: (i) speeded executive and fluency, (ii) episodic memory, and (iii) working memory. Associations were examined with bivariate tests and multivariate models.

RESULTS

Depressed individuals with a FRAIL score >1 had worse performance than nonfrail depressed across all three factors; however, speeded executive and fluency was the only factor that remained significant after controlling for depression symptom severity and demographic characteristics.

CONCLUSIONS

Although physical frailty is associated with broad neurocognitive deficits in LLD, it is most robustly associated with deficits in speeded executive functions and verbal fluency. Causal inferences are limited by the cross-sectional design, and future research would benefit from a comparison group of nondepressed older adults with similar levels of frailty. Research is needed to understand the mechanisms underlying associations among depression symptoms, physical frailty, and executive dysfunction and how they are related to the cognitive and symptomatic course of LLD.

Cognitive function in the prefrailty and frailty syndrome

OBJECTIVES

To explore the relationship between cognitive function and frailty.

DESIGN

A cross-sectional study using data from Wave 1 of The Irish Longitudinal Study on Ageing, a population representative study of adults aged 50 and older in the Republic of Ireland.

SETTING

Community-dwelling adults completed a home- or health center-based nurse-led assessment.

PARTICIPANTS

Individuals aged 50 and older without a history of stroke, Parkinson's disease, or severe cognitive impairment (Mini-Mental State Examination (MMSE) score <18) and not taking antidepressants (N = 4,649).

MEASUREMENTS

A cognitive battery including MMSE, Montreal Cognitive Assessment, Color Trails Test, Cambridge Mental Disorders of the Elderly Examination memory and executive function subtests, 10-word recall, Sustained Attention to Response Task, and choice reaction time was used to generate composite scores of cognitive domains. Frailty was assessed according to weakness, slowness, exhaustion, low physical activity, and weight loss.

RESULTS

After full adjustment, cognitive function across all domains except self-rated memory and processing speed was significantly worse in prefrail and frail participants (P < .05) than in those who were robust. Weakness and walking speed were most consistently linked to poorer cognition, whereas low activity and weight loss were not independently associated with any cognitive domain. Exhaustion was associated with global cognition (B = -0.18 ± 0.06), with some evidence of links to objectively measured and self-rated memory.

CONCLUSION

Cognitive function is worse across multiple cognitive domains in prefrail and frail individuals aged 50 and older than in those who are robust, although the absolute differences are small after adjusting for confounding factors.

Hospitalization and cognitive decline: Can the nature of the relationship be deciphered?

BACKGROUND

Evidence for a relationship between hospitalization and incident cognitive decline exists mainly in the literature focusing on critical care hospitalization. Recent studies, however, have also found an association between noncritical care hospitalization and the development of cognitive decline.

OBJECTIVE

This article will review the literature pertaining to hospitalization and cognitive decline, including hospitalizations for both critical and noncritical care, and in medical and surgical patients. The article will also explore the various factors that have been implicated in the development of cognitive decline and dementia.

METHODS

Review of the literature was completed using PubMed and Medline search programs.

RESULTS

Several articles supporting evidence for the association between hospitalization and cognitive decline are available. Evidence for potential mediating factors also does exist.

CONCLUSIONS

There is evidence to support an association between hospitalization and development of cognitive decline. Factors that could mediate this association include, but may not be limited to, delirium, medications, stress, and depression. There is a need for further research in this area in order to better understand the underlying pathophysiology involved in the development of cognitive decline and dementia and to determine if preventive measures might be beneficial in decreasing risk for cognitive decline for patients who are hospitalized.

Frailty and cognitive impairment--a review of the evidence and causal mechanisms

Incidence rates of cognitive impairment and dementia are rising with the ageing population. Meanwhile, the limited success of current treatments has led to a search for early markers of dementia which could predict future progression or improve quality of life for those already suffering from the disease. One focus has been on the correlation between physical and cognitive measures with an increasing interest in the association between frailty and cognitive decline. Frailty is an age-related syndrome described as the decreased ability of an organism to respond to stressors. A number of epidemiological studies have reported that frailty increases the risk of future cognitive decline and that cognitive impairment increases the risk of frailty suggesting that cognition and frailty interact within a cycle of decline associated with ageing. This paper reviews the evidence for an association between frailty and cognitive impairment and outlines some of the mechanisms that potentially underpin this relationship from brain neuropathology and hormonal dysregulation to cardiovascular risk and psychological factors.

Impact of familiar and unfamiliar settings on cooking task assessments in frail older adults with poor and preserved executive functions

BACKGROUND

Hospitalized frail older patients are usually assessed for their ability to perform some daily living activities in a clinical setting prior to discharge. However, assessments that take place in this unfamiliar environment might not be as representative of their functional performance as assessments at home. This may be related to a decline in some cognitive components, such as executive functions (EF), which enable one to cope with new environments. This study thus aims to compare cooking task performance in familiar and unfamiliar settings in a population of frail older adults with poor and preserved EF.

METHODS

Thirty-seven frail older adults were assigned to one of two groups: poor EF or preserved EF. Participants performed two cooking tasks in familiar and unfamiliar settings, using a counterbalanced design. Their performance was assessed with a reliable tool based on observation of motor and process skills (Assessment of Motor and Process Skills).

RESULTS

Thirty-three participants were retained for analysis. They demonstrated significantly better motor skills (F = 5.536; p = 0.025) and process skills (F = 8.149; p = 0.008) in the familiar setting. The difference between settings was particularly marked for process skills in participants with poor EF (F = 16.920; p < 0.001).

CONCLUSIONS

This study suggests that a home setting may be preferable for a more accurate assessment of cooking task performance in frail older adults, especially those with poor EF. These findings highlight the risk of underestimating frail older adults' performance when assessed in an unfamiliar setting (e.g. hospital), which could lead to inefficient allocation of home care services.

The Montreal Cognitive Assessment (MoCA) in geriatric rehabilitation: psychometric properties and association with rehabilitation outcomes

BACKGROUND

Cognitive status has been reported to be an important predictor of rehabilitation outcome. The Montreal Cognitive Assessment (MoCA) was designed to overcome some of the limitations of established cognitive screening tools such as the Mini-Mental State Examination (MMSE). The purpose of this study is to evaluate the psychometric characteristics of the MoCA as a screening tool in a geriatric rehabilitation program and its ability to predict rehabilitation outcome.

METHODS

Forty-seven geriatric rehabilitation program patients participated in the study. Assessments of each patient's functional (Functional Independence Measure) and cognitive status (MMSE and MoCA) were performed. Information on discharge destinations were obtained and rehabilitation efficacy and efficiency scores were calculated.

RESULTS

Significant correlations were found between the MoCA and other cognitive status measures. Cognitive status at admission and successful rehabilitation were also associated. Defining rehabilitation success on the basis of relative functional efficacy (an indicator that includes the patient's potential for improvement), the sensitivity and specificity of the MoCA were 80% and 30% respectively. The attention subscale of the MoCA was also uniquely predictive of rehabilitation success. The attention subscale (cutoff 5/6) of the MoCA had a sensitivity of 40% and specificity of 90%, as did the MMSE.

CONCLUSIONS

As a cognitive screening tool, the MoCA appears to have acceptable psychometric properties. Results suggest that the MoCA can have a considerable advantage over the MMSE in sensitivity and equivalence in specificity using both total and attention scale scores. The MoCA may be a more useful measure for detecting cognitive impairment and predicting rehabilitation outcome in this population.

Influence of multimorbidity on cognition in a normal aging population: a 12-year follow-up in the Maastricht Aging Study

OBJECTIVE

The prevalence of multimorbidity has risen considerably because of the increase in longevity and the rapidly growing number of older individuals. Today, only little is known about the influence of multimorbidity on cognition in a normal healthy aging population. The primary aim of the present study was to investigate the effect of multimorbidity on cognition over a 12-year period in an adult population with a large age range.

METHODS

Data were collected as part of the Maastricht Aging Study (MAAS), a prospective study into the determinants of cognitive aging. Eligible MAAS participants (N = 1763), 24-81 years older, were recruited from the Registration Network Family Practices (RNH) which enabled the use of medical records. The association between 96 chronic diseases, grouped into 23 disease clusters, and cognition on baseline, at 6 and 12 years of follow-up, were analyzed. Cognitive performance was measured in two main domains: verbal memory and psychomotor speed. A multilevel statistical analysis, a method that respects the hierarchical data structure, was used.

RESULTS

Multiple disease clusters were associated with cognition during a 12-year follow-up period in a healthy adult population. The disease combination malignancies and movement disorders multimorbidity also appeared to significantly affect cognition.

CONCLUSIONS

The current results indicate that a variety of medical conditions adversely affects cognition. However, these effects appear to be small in a normal healthy aging population.

Pervasive cognitive impairment in acute rehabilitation inpatients without brain injury

OBJECTIVE

To establish feasibility for the hypothesis that patients in acute rehabilitation who are hospitalized for disorders not known to involve cerebral injury can have significant cognitive impairment.

DESIGN

A comparison of performances on neuropsychological tests between 2 samples of subjects: inpatients in an acute rehabilitation hospital without known cerebral disease and normal community-dwelling persons.

SETTING

Acute inpatient rehabilitation hospital.

PATIENTS AND PARTICIPANTS

Nineteen hospitalized patients without delirium who were screened for pre-existing cerebral and psychiatric illness, dementia, and dependency in basic self-care skills before hospitalization. Eighteen community-dwelling persons who were not different in terms of age and education served as the control group.

METHODS

Participants completed 10 commonly used neuropsychological tests of executive, language, and memory functions. Data were analyzed by using multivariate analysis of variance.

MAIN OUTCOME MEASUREMENTS

Raw scores on the 10 neuropsychological tests.

RESULTS

Hospitalized patients performed significantly worse on 9 of 10 tests than community-dwelling participants. Older hospitalized participants had significantly greater cognitive impairment than younger hospitalized participants, which suggested increased susceptibility to effects of hospitalization on cognition.

CONCLUSIONS

Patients hospitalized without brain injury, and especially elderly patients, should be carefully monitored for cognitive deficits that may affect posthospitalization quality of living. Further research is needed to determine whether the cognitive deficits in such patients persist after discharge and affect functional independence, and to identify mechanisms for the deficits. Furthermore, the use of hospitalized participants without brain injury as control subjects in neuropsychological studies of brain injury should be balanced with an additional comparison group of matched, neurologically healthy, normal subjects who live in the community to control for cognitive impairments that are associated with acute hospitalization.

High medical co-morbidity and family history of dementia is associated with lower cognitive function in older patients

BACKGROUND

Risk factors for cognitive decline in ageing are multifactorial, including medical co-morbidities and familial genetic risk.

OBJECTIVES

To assess the effect of medical co-morbidity and family history of dementia on cognitive performance in older outpatients of family practitioners.

METHODS

Analysis of 535 outpatients from 11 practices aged 65 and older, without a diagnosis of dementia. Information on medical co-morbidities, family history of dementia and cognitive test data were obtained.

RESULTS

Patients were classified into high or low medical co-morbidities (<7 versus >8) and positive or negative family history of dementia. After controlling for age, education, gender and depression, global cognitive test scores, as well as memory, executive function, spatial ability and attention were significantly lower for persons having a high number of medical co-morbidities. Cognitive test scores were not significantly different for persons with or without a family history of dementia. A significant interaction between medical co-morbidities and family history of dementia was observed for the global cognitive score, executive function and spatial ability. Those persons with a high number of medical co-morbidities and positive family history of dementia had the lowest performance. Separate regression analysis assessing individual disease risk factors (e.g. hypertension and diabetes) did not find any relationship between specific medical variables and cognitive test scores for any of the subgroups.

CONCLUSIONS

A high number of medical co-morbidities in addition to a reported family history of dementia are particularly detrimental to cognitive performance in elderly non-demented family practice patients.

Home and Clinical Assessments of Instrumental Activities of Daily Living: What Could Explain the Difference between Settings in Frail Older Adults, If Any?

Background:

Older patients are usually assessed by occupational therapists in hospital before going home. However, for many frail older adults, this assessment in an unfamiliar environment might not be as representative of their functional abilities as an assessment at home. The aim of this literature review was to determine if differences exist between home and clinical instrumental activities of daily living (IADL) assessments of frail older adults and identify factors that might explain those differences, if any.

Method:

The sources of the review data were Medline, CINAHL, AMED, PsycINFO, Embase and Current Content from 1988 to 2008. As few relevant studies concerning frail people were found, the search was extended to mixed-age and older adult populations. Ten articles were retained.

Main findings:

The results suggest differences in IADL assessment between settings for older adults without dementia. Some factors, such as familiarity with the environment and coping skills, might explain those differences. Based on this review, similar results might be expected with frail older people.

Implications for practice:

Given the dearth of literature on this topic, further research is needed to compare home and clinical assessments and measure relevant factors in a frail population. Helping occupational therapists to identify frail patients, who may show different abilities in unfamiliar settings, could mean more appropriate services after discharge from hospital.

Amisulpride doses and plasma levels in different age groups of patients with schizophrenia or schizoaffective disorder

Because of a unique pharmacodynamic profile, amisulpride seems appropriate for treatment of elderly patients with schizophrenia. In a large-scale naturalistic therapeutic drug monitoring study, daily amisulpride dose, trough and dose-corrected amisulpride plasma levels, co-medication, clinical effectiveness (CGI) and side effects (UKU) were compared between age groups in 395 patients with schizophrenia or schizoaffective disorder (46% women; mean age 39.1 +/- 14.2 years, range 18-83 years) under amisulpride therapy. Mean amisulpride doses (574 +/- 269 mg/day), plasma levels (304 +/- 274 ng/mL), dose-corrected amisulpride plasma levels (C/D ratios, 0.52 +/- 0.41 ng/mL:mg), clinical response (at least moderate improvement, 71.6%), and side effects (any side effect, 32.2%; extrapyramidal symptoms, 14.9%) were comparable between age groups (P > 0.25). At higher age, significantly more benzodiazepines (P = 0.04), non-benzodiazepine hypnotics (P = 0.004) and non-psychotropic medications (P < 0.0001) were prescribed. The naturalistic study showed higher C/D ratios in women (P = 0.019) and a slight increase of C/D ratios with age (P = 0.026), but no substantial age-dependent effects on amisulpride doses or plasma levels. In patients above 60 years, clinical response was associated with lower amisulpride plasma levels (P = 0.016) at comparable doses. Neither the age-dependent decrease of amisulpride clearance nor the significantly higher prevalence of co-morbidity and co-medication seem to be the reasons for definite clinical concerns against amisulpride treatment of elderly if contraindications are seriously taken.

Somatic chronic diseases and 6-year change in cognitive functioning among older persons

The influence of seven highly prevalent somatic chronic diseases on changes in cognitive functioning is investigated in older persons in a prospective design covering a 6-year follow-up period. The data were collected as part of the Longitudinal Aging Study Amsterdam (LASA). The associations between chronic diseases and cognitive functioning during 6 years of follow-up were analyzed among 1358 respondents (age 62-85) using generalized estimated equations (GEE). Cognitive tests were used to assess: general cognitive functioning, fluid intelligence, information processing speed and memory performance. In the fully adjusted models diabetes mellitus, stroke and peripheral artherosclerosis were associated with cognitive decline during a 6-year follow-up period in older persons. In the unadjusted models cardiac disease was negatively associated with memory function. However, after the correction for possible confounders this association became positive. Cancer was also associated with better memory function. A faster decline in especially memory function was found for diabetes mellitus, stroke, cancer, and peripheral artherosclerosis. The study shows that in older persons specific chronic diseases (diabetes mellitus, stroke, cancer, and peripheral artherosclerosis) are associated with decline in one or more domains of cognitive functioning during a 6-year follow-up period. These findings further stress that careful clinical evaluation of cognitive functioning in older persons with these diseases is required in order to provide adequate care.

Assessing neurocognitive outcomes after critical illness: are delirium and long-term cognitive impairments related?

PURPOSE OF REVIEW

Critically ill patients have a high risk of developing neurologic dysfunction including delirium and long-term cognitive impairment. In this paper we examine possible relationships between delirium and long-term cognitive impairments and explore this in the context of critical illness.

RECENT FINDINGS

Critical illness and its treatment can lead to neurologic morbidity including neuropathological abnormalities, delirium, and cognitive impairments. The association between delirium and long-term cognitive impairments has been shown in a number of populations. Among intensive care unit cohorts, delirium appears to be one of many possible causes of cognitive impairments and may be a leading modifiable cause. The mechanisms of both delirium and intensive care unit related cognitive impairment remain unclear, although a variety of common mechanisms have been proposed.

SUMMARY

Potential neurologic consequences of critical illness include delirium and long-term cognitive impairments. Defining the extent of their association in intensive care unit cohorts is an important research priority due to the high prevalence of delirium and persistent cognitive impairments in critically ill patients. Future research should focus on strategies for the early identification of delirium and cognitive impairments, elucidating mechanisms of brain injury, and the development and implementation of therapeutic modalities designed to prevent or decrease delirium and cognitive morbidity.