Delirium and long-term cognitive impairment

A longitudinal study of motor subtypes in delirium: frequency and stability during episodes

OBJECTIVE

Motor-defined subtypes are a promising means of identifying clinically relevant patient subgroups but little is known about their course and stability during a delirium episode.

METHODS

We assessed 100 consecutive adult palliative care patients with DSM-IV delirium twice weekly during their episodes using the Delirium Motor Subtype Scale (DMSS), Delirium Rating Scale-Revised-98 (DRS-R98) and Cognitive Test for Delirium (CTD). DMSS subtypes were assigned for each assessment and analysed for stability within patients during episodes.

RESULTS

Across all assessments (n=303; mean 3 per patient, range 2-9), subtype occurrence was hypoactive (35%), mixed (26%), hyperactive (15%) and no subtype (24%). "No subtype" was associated with significantly lower DRS-R98 severity scores, of which 80% were subsyndromal, whereas mixed subtype assessments were the most impaired on the DRS-R98 and CTD. Subtypes were stable within delirium episodes in 62% of patients: 29% hypoactive, 18% mixed, 10% hyperactive and 6% no-subtype. The DRS-R98 noncognitive subscale scores differed across groups whereas cognitive subscale scores did not (p<0.001).

CONCLUSIONS

We conclude that motor subtypes occur in nearly all patients with full syndromal delirium and are often stable during an episode. Subtypes exhibited comparable levels of cognitive impairment but differed in non-cognitive symptoms, supporting the importance of cognitive testing to detect delirium in less overt cases.

A systematic literature review of cerebrospinal fluid biomarkers in delirium

BACKGROUND

Cerebrospinal fluid (CSF) analysis has great potential to advance understanding of delirium pathophysiology.

METHODS

A systematic literature review of CSF studies of DSM or ICD delirium was performed.

RESULTS

In 8 studies of 235 patients, delirium was associated with: elevated serotonin metabolites, interleukin-8, cortisol, lactate and protein, and reduced somatostatin, β-endorphin and neuron-specific enolase. Elevated acetylcholinesterase predicted poor outcome after delirium and higher dopamine metabolites were associated with psychotic features.

CONCLUSIONS

No clear conclusions emerged, but the current literature suggests multiple areas for further investigation with more detailed studies.

Features of subsyndromal and persistent delirium

BACKGROUND

Longitudinal studies of delirium phenomenology are lacking.

AIMS

We studied features that characterise subsyndromal delirium and persistent delirium over time.

METHOD

Twice-weekly evaluations of 100 adults with DSM-IV delirium using the Delirium Rating Scale-Revised-98 (DRS-R98) and Cognitive Test for Delirium (CTD). The generalised estimating equation method identified symptom patterns distinguishing full syndromal from subsyndromal delirium and resolving from persistent delirium.

RESULTS

Participants (mean age 70.2 years (s.d. = 10.5)) underwent 323 assessments (range 2-9). Full syndromal delirium was significantly more severe than subsyndromal delirium for DRS-R98 thought process abnormalities, delusions, hallucinations, agitation, retardation, orientation, attention, and short- and long-term memory items, and CTD attention, vigilance, orientation and memory. Persistent full syndromal delirium had greater disturbance of DRS-R98 thought process abnormalities, delusions, agitation, orientation, attention, and short- and long-term memory items, and CTD attention, vigilance and orientation.

CONCLUSIONS

Full syndromal delirium differs from subsyndromal delirium over time by greater severity of many cognitive and non-cognitive symptoms. Persistent delirium involves increasing prominence of recognised core diagnostic features and cognitive impairment.

Cognitive functioning, mental health, and quality of life in ICU survivors: an overview

The significant and sometimes permanent effects of critical illness on wide-ranging aspects of functioning are increasingly recognized. Among the areas affected are acute and long-term cognitive functioning, depression, anxiety, PTSD, and quality of life. These and other areas are increasingly being studied and indeed are increasingly the focus of clinical attention and investigations. These conditions have been a focus of attention for more than a dozen years, with much improvement occurring in the ability to characterize these phenomena. For instance, in intervening years, it has been learned that cognitive impairment is highly prevalent and functionally disruptive and that it occurs in wide-ranging domains. Key questions remain unanswered with regard to vital questions such as determining causes, risk factors, and mechanisms as well as the degree to which brain injuries associated with critical illness are amenable to rehabilitation. Little remains known about the effects of critical illness on elderly ICU cohorts and on the neurologic functioning of individuals with preexisting impairment versus those who are normal. Few data exist regarding the development of strategies designed to prevent the emergence of neuropsychological deficits after critical illness. Although great progress has been made and is ongoing, a pressing need exists for additional investigation of cognitive impairment and other conditions,such as PTSD and quality of life after critical illness, that will seek to untangle the many pertinent questions related to this condition and that will ultimately offer help and hope to the thousands of survivors affected by this condition.

Risk of serious falls associated with oxybutynin and tolterodine: a population based study

PURPOSE

We compared the short-term risk of falls among recipients of oxybutynin or tolterodine to treat urinary incontinence.

MATERIALS AND METHODS

We conducted a population based, retrospective cohort study with propensity score matching among patients 66 years old or older who commenced treatment with oxybutynin or tolterodine in Ontario, Canada. The primary outcome was a hospital visit for a fall within 90 days of drug initiation. Secondary outcomes included hospital visits for fractures, delirium or all cause mortality.

RESULTS

We found no difference in the risk of falls among users of oxybutynin vs tolterodine (adjusted hazard ratio 1.04, 95% CI 0.95 to 1.14). Secondary analyses revealed no differential risk of fractures (aHR 0.96, 95% CI 0.82 to 1.13) or delirium (aHR 0.90, 95% CI 0.66 to 1.23) associated with oxybutynin. However, statistically significant increases in the risk of all cause hospitalization (aHR 1.12, 95% CI 1.07 to 1.17) and death (aHR 1.20, 95% CI 1.07 to 1.35) were seen with oxybutynin.

CONCLUSIONS

Oxybutynin was not associated with a short-term increased risk of hospital visit for falls, fractures or delirium compared to tolterodine. Further research is needed to confirm whether oxybutynin is associated with an increased risk of hospitalization or death.

Diabetes and psychiatric disorders

Interface of diabetes and psychiatry has fascinated both endocrinologists and mental health professionals for years. Diabetes and psychiatric disorders share a bidirectional association -- both influencing each other in multiple ways. The current article addresses different aspects of this interface. The interaction of diabetes and psychiatric disorders has been discussed with regard to aetio-pathogenesis, clinical presentation, and management. In spite of a multifaceted interaction between the two the issue remains largely unstudied in India.

Statins and brain dysfunction: a hypothesis to reduce the burden of cognitive impairment in patients who are critically ill

Delirium is a frequent form of acute brain dysfunction in patients who are critically ill and is associated with poor clinical outcomes, including a critical illness brain injury that may last for months to years. Despite widespread recognition of significant adverse outcomes, pharmacologic approaches to prevent or treat delirium during critical illness remain unproven. We hypothesize that commonly prescribed statin medications may prevent and treat delirium by targeting molecular pathways of inflammation (peripheral and central) and microglial activation that are central to the pathogenesis of delirium. Systemic inflammation, a principal mechanism of injury, for example, in sepsis, acute respiratory distress syndrome, and other critical illnesses, can cause neuronal apoptosis, blood-brain barrier injury, brain ischemia, and microglial activation. We hypothesize that the known pleiotropic effects of statins, which attenuate such neuroinflammation, may redirect microglial activation and promote an antiinflammatory phenotype, thereby offering the potential to reduce the public health burden of delirium and its associated long-term cognitive injury.

Neuropsychiatric and cognitive profile of patients with DSM-IV delirium referred to an old age psychiatry consultation-liaison service

BACKGROUND

The phenomenology of delirium is understudied, including how the symptom profile varies across populations. The aim of this study was to explore phenomenology occurring in patients with delirium referred to an old age psychiatry consultation-liaison setting and compare with delirium occurring in palliative care patients.

METHODS

Consecutive cases of DSM-IV delirium were assessed with the Delirium Rating scale Revised-98 (DRS-R98) and Cognitive Test for Delirium (CTD).

RESULTS

Eighty patients (mean age 79.3 ± 7.7 years; mean DRS-R98 total score 21.7 ± 4.9 and total CTD score 10.2 ± 6.3) were included. Forty patients (50%) with comorbid dementia were older, had a longer duration of symptoms at referral, and more severe delirium due to greater cognitive impairments. Inattention (100%) was the most prominent cognitive disturbance, while sleep-wake cycle disturbance (98%), altered motor activity (97%), and thought process abnormality (96%) were the most frequent DRS-R98 non-cognitive features. Inattention was associated with severity of other cognitive disturbances on both the DRS-R98 and CTD, but not with DRS-R98 non-cognitive items. The phenomenological profile was similar to palliative care but with more severe delirium due to greater cognitive and non-cognitive disturbance.

CONCLUSION

Delirium is a complex neuropsychiatric syndrome with generalized cognitive impairment and disproportionate inattention. Sleep-wake cycle and motor-activity disturbances are also common. Comorbid dementia results in a similar phenomenological pattern but with greater cognitive impairment and later referral.

Systemic inflammation and delirium: important co-factors in the progression of dementia

It is widely accepted that inflammation plays some role in the progression of chronic neurodegenerative diseases such as AD (Alzheimer's disease), but its precise role remains elusive. It has been known for many years that systemic inflammatory insults can signal to the brain to induce changes in CNS (central nervous system) function, typically grouped under the syndrome of sickness behaviour. These changes are mediated via systemic and CNS cytokine and prostaglandin synthesis. When patients with dementia suffer similar systemic inflammatory insults, delirium is a frequent consequence. This profound and acute exacerbation of cognitive dysfunction is associated with poor prognosis: accelerating cognitive decline and shortening time to permanent institutionalization and death. Therefore a better understanding of how delirium occurs during dementia and how these episodes impact on existing neurodegeneration are now important priorities. The current review summarizes the relationship between dementia, systemic inflammation and episodes of delirium and addresses the basic scientific approaches currently being pursued with respect to understanding acute cognitive dysfunction during aging and dementia. In addition, despite there being limited studies on this subject, it is becoming increasingly clear that infections and other systemic inflammatory conditions do increase the risk of AD and accelerate the progression of established dementia. These data suggest that systemic inflammation is a major contributor to the progression of dementia and constitutes an important clinical target.

Insulin-like growth factor I and the pathogenesis of delirium: a review of current evidence

Delirium is a frequent complication in medically ill elderly patients that is associated with serious adverse outcomes including increased mortality. Delirium risk is linked to older age, dementia, and illness that involves activation of inflammatory responses. IGF-I is increasingly postulated as a key link between environmental influences on body metabolism with a range of neuronal activities and has been described as the master regulator of the connection between brain and bodily well-being. The relationships between IGF-I and ageing, cognitive impairment and inflammatory illness further support a possible role in delirium pathogenesis. Five studies of IGF-I in delirium were identified by a systematic review. These conflicting findings, with three of the five studies indicating an association between IGF-1 and delirium occurrence, may relate to the considerable methodological differences in these studies. The relevance of IGF-I and related factors to delirium pathogenesis can be clarified by future studies which account for these issues and other confounding factors. Such work can inform therapeutic trials of IGF-I and/or growth hormone administration.

A clinical update on delirium: from early recognition to effective management

Delirium is a neuropsychiatric syndrome characterized by altered consciousness and attention with cognitive, emotional and behavioural symptoms. It is particularly frequent in elderly people with medical or surgical conditions and is associated with adverse outcomes. Predisposing factors render the subject more vulnerable to a congregation of precipitating factors which potentially affect brain function and induce an imbalance in all the major neurotransmitter systems. Early diagnosis of delirium is crucial to improve the prognosis of patients requiring the identification of subtle and fluctuating signs. Increased awareness of clinical staff, particularly nurses, and routine screening of cognitive function with standardized instruments, can be decisive to increase detection rates of delirium. General measures to prevent delirium include the implementation of protocols to systematically identify and minimize all risk factors present in a particular clinical setting. As soon as delirium is recognized, prompt removal of precipitating factors is warranted together with environmental changes and early mobilization of patients. Low doses of haloperidol or olanzapine can be used for brief periods, for the behavioural control of delirium. All of these measures are a part of the multicomponent strategy for prevention and treatment of delirium, in which the nursing care plays a vital role.

The evaluation and management of delirium among older persons

This article reviews the pathophysiology, prevalence, incidence, and consequences of delirium, focusing on the evaluation of delirium, the published models of care for prevention in patients at risk of delirium, and management of patients for whom delirium is not preventable. Evidence on why physical restraints should not be used for patients with delirium is reviewed. Current available evidence on antipyschotics does not support the role for the general use in the treatment of delirium. An example of a restraint-free, nonpharmacologic management approach [called the TADA approach (tolerate, anticipate, and don't agitate)] is presented.

Delirium in acute stroke: a predictor of subsequent cognitive impairment? A two-year follow-up study

OBJECTIVE

Delirium is an independent risk factor for cognitive impairment and development of dementia in medical patients. It has never been thoroughly studied whether this association is also present in the stroke population. Our aim was to evaluate the effects of delirium in the acute phase after stroke on cognitive functioning two years later.

METHODS

Two years after stroke, 50 patients (22 with and 28 without delirium in the acute phase) were assessed on two screening instruments for dementia and a neuropsychological test battery.

RESULTS

Delirium was an independent predictor for development of dementia as assessed by the Clinical Dementia Rating Scale (odds ratio (OR) 4.7; 95% confidence interval (CI) 1.08 to 20.42) and by the Rotterdam-CAMCOG (OR 7.2, 95% CI 1.88 to 27.89). Cognitive domains most affected in patients with previous delirium were memory, language, visual construction and executive functioning.

CONCLUSIONS

Delirium in the acute phase after stroke is an independent predictor for severe cognitive impairment two years after stroke. These findings emphasize the importance of both rapid detection and treatment of delirium after stroke. Furthermore, periodic monitoring and evaluation of cognitive functioning in these vulnerable patients in the years after stroke is strongly recommended.

The neuropsychological course of acute delirium in adult hematopoietic stem cell transplantation patients

Although delirium is a common medical comorbidity with altered cognition as its defining feature, few publications have addressed the neuropsychological prodrome, profile, and recovery of patients tested during delirium. We characterize neuropsychological performance in 54 hemapoietic stem cell/bone marrow transplantation (BMT) patients shortly before, during, and after delirium and in BMT patients without delirium and 10 healthy adults. Patients were assessed prospectively before and after transplantation using a brief battery. BMT patients with delirium performed more poorly than comparisons and those without delirium on cross-sectional and trend analyses. Deficits were in expected areas of attention and memory, but also in psychomotor speed and learning. The patients with delirium did not return to normative "average" on any test during observation. Most tests showed a mild decline in the visit before delirium, a sharp decline with delirium onset, and variable performance in the following days. This study adds to the few investigations of neuropsychological performance surrounding delirium and provides targets for monitoring and early detection; Trails A and B, RBANS Coding, and List Recall may be useful for delirium assessment.

Clinical associations of delirium in hospitalized adult patients and the role of on admission presentation

OBJECTIVE

To describe clinical associations of delirium in hospitalized patients and relationships to on admission presentation.

DESIGN

Retrospective analysis of an administrative hospitalization database 1998-2007.

SETTING

Acute care hospitalizations in the New York State (NYS).

MEASUREMENTS

Four categories of diagnosis related group (DRG) hospitalizations were extracted from a NYS administrative database: pneumonia, congestive heart failure, urinary tract/kidney infection (UTI), and lower extremity orthopedic surgery (LEOS) DRGs. These hospitalizations were examined for clinical associations with delirium coding both on and after admission.

RESULTS

Delirium was coded in 0.8% of the cohort, of which an on admission diagnosis was present in 59%. On admission delirium was strongly associated with dementia (adjusted odds ratio 0, 95%CI 5.8-6.3) and with adverse drug effects (ADEs) (adjusted odds ratio 4.6, 95%CI 4.3, 5.0). After admission delirium was even more highly associated with ADEs (adjusted odds ratio 22.2, 95%CI 20.7-23.7). The UTI DRG category had the greatest proportion of on admission delirium. However after admission delirium was more common in the LEOS DRG category. Over time, there was a greater increase in delirium proportions in the UTI DRG category, and an overall increase in coding for encephalopathy states (potential alternative delirium descriptors).

CONCLUSION

ADEs play an important role in delirium regardless of whether or not it is present on admission. While the finding that most delirium hospitalizations presented on admission suggests that delirium impacts more as a clinical admitting determinant, in-hospital prevention strategies may still have benefit in targeted settings where after admission delirium is more frequent, such as patients with LEOS.

Delirium as a predictor of long-term cognitive impairment in survivors of critical illness

OBJECTIVE

To test the hypothesis that duration of delirium in the intensive care unit is an independent predictor of long-term cognitive impairment after critical illness requiring mechanical ventilation.

DESIGN

Prospective cohort study.

SETTING

Medical intensive care unit in a large community hospital in the United States.

PATIENTS

Mechanically ventilated medical intensive care unit patients who were assessed daily for delirium while in the intensive care unit and who underwent comprehensive cognitive assessments 3 and 12 mos after discharge.

MEASUREMENTS AND MAIN RESULTS

Of 126 eligible patients, 99 survived>or=3 months after critical illness; long-term cognitive outcomes were obtained for 77 (78%) patients. Median age was 61 yrs, 51% were admitted with sepsis/acute respiratory distress syndrome, and median duration of delirium was 2 days. At 3-mo and 12-mo follow-up, 79% and 71% of survivors had cognitive impairment, respectively (with 62% and 36% being severely impaired). After adjusting for age, education, preexisting cognitive function, severity of illness, severe sepsis, and exposure to sedative medications in the intensive care unit, increasing duration of delirium was an independent predictor of worse cognitive performance-determined by averaging age-adjusted and education-adjusted T-scores from nine tests measuring seven domains of cognition-at 3-mo (p=.02) and 12-mo follow-up (p=.03). Duration of mechanical ventilation, alternatively, was not associated with long-term cognitive impairment (p=.20 and .58).

CONCLUSIONS

In this study of mechanically ventilated medical intensive care unit patients, duration of delirium (which is potentially modifiable) was independently associated with long-term cognitive impairment, a common public health problem among intensive care unit survivors.

The neuroinflammatory hypothesis of delirium

Delirium is a neuropsychiatric syndrome characterized by a sudden and global impairment in consciousness, attention and cognition. It is particularly frequent in elderly subjects with medical or surgical conditions and is associated with short- and long-term adverse outcomes. The pathophysiology of delirium remains poorly understood as it involves complex multi-factorial dynamic interactions between a diversity of risk factors. Several conditions associated with delirium are characterized by activation of the inflammatory cascade with acute release of inflammatory mediators into the bloodstream. There is compelling evidence that acute peripheral inflammatory stimulation induces activation of brain parenchymal cells, expression of proinflammatory cytokines and inflammatory mediators in the central nervous system. These neuroinflammatory changes induce neuronal and synaptic dysfunction and subsequent neurobehavioural and cognitive symptoms. Furthermore, ageing and neurodegenerative disorders exaggerate microglial responses following stimulation by systemic immune stimuli such as peripheral inflammation and/or infection. In this review we explore the neuroinflammatory hypothesis of delirium based on recent evidence derived from animal and human studies.

Systemic inflammation induces acute working memory deficits in the primed brain: relevance for delirium

Delirium is an acute, severe neuropsychiatric syndrome, characterized by cognitive deficits, that is highly prevalent in aging and dementia and is frequently precipitated by peripheral infections. Delirium is poorly understood and the lack of biologically relevant animal models has limited basic research. Here we hypothesized that synaptic loss and accompanying microglial priming during chronic neurodegeneration in the ME7 mouse model of prion disease predisposes these animals to acute dysfunction in the region of prior pathology upon systemic inflammatory activation. Lipopolysaccharide (LPS; 100 μg/kg) induced acute and transient working memory deficits in ME7 animals on a novel T-maze task, but did not do so in normal animals. LPS-treated ME7 animals showed heightened and prolonged transcription of inflammatory mediators in the central nervous system (CNS), compared with LPS-treated normal animals, despite having equivalent levels of circulating cytokines. The demonstration that prior synaptic loss and microglial priming are predisposing factors for acute cognitive impairments induced by systemic inflammation suggests an important animal model with which to study aspects of delirium during dementia.

Systemic infection and delirium: when cytokines and acetylcholine collide

Systemic infection and drugs with anticholinergic effects are well-recognised and prevalent risk factors for delirium in elderly people. Experimental findings and neuropathological observations suggest that activation of microglia is pivotal for mediation of the behavioural effects of systemic infections. The microglial response is usually regulated tightly, but defensive features could turn neurotoxic once microglial cells escape from cholinergic inhibition. A self-propelling neuroinflammatory reaction might follow, and this cascade could account for the strong association between delirium and long-term cognitive impairment and even dementia. Here, we propose a hypothetical model, suggesting that poor outcome after delirium can be averted in vulnerable elderly people by use of readily available drugs. Agents that either restore cholinergic control of microglia or directly inhibit neuroinflammation warrant testing in clinical trials.

Cognitive functioning, mental health, and quality of life in ICU survivors: an overview

Critical illness can and often does lead to significant cognitive impairment and to the development of psychological disorders. These conditions are persistent and, although they improve with time, often fail to completely abate. Although the functional correlates of cognitive and psychological morbidity (depression, anxiety, and posttraumatic stress disorder) have been studied, they may include poor quality of life, inability to return to work or to work at previously established levels, and inability to function effectively in emotional and interpersonal domains. The potential etiologies of cognitive impairment and psychological morbidity in ICU survivors are particularly poorly understood and may vary widely across patients. Potential contributors may include the potentially toxic effects of sedatives and narcotics, delirium, hypoxia, glucose dysregulation, metabolic derangements, and inflammation. Patients with preexisting vulnerabilities, including predisposing genetic factors, and frail elderly populations may be at particular risk for emergence of acceleration of conditions such as mild cognitive impairment.

Study on the efficacy and tolerability of amisulpride in medical/surgical inpatients with delirium admitted to a general hospital

PURPOSE

To evaluate the efficacy and safety of amisulpride in medical inpatients who present with delirium.

METHOD

Open label prospective study with 7-day follow-up. Forty hospital inpatients with delirium were recruited, seven of whom died and two of whom refused medication. The average dose of amisulpride for delirium treatment was 200-300 mg/day. Daily assessments were performed with Delirium Rating Scale (DRS), Positive Subscale of the Positive and Negative Syndrome Scale (PANSS-P), Mini Mental State Examination (MMSE), Neurological Subscale of the UKU side effect rating scale. Variance analysis was performed through repeated measurements, with the general linear model with paired comparisons and Bonferroni correction for each measured variable.

RESULTS

Patients showed significant improvement on the DRS from the first day of treatment DRS = 17.55 until day 7 DRS = 7.26 (F = 92.485; p < 0.001), psychotic symptoms improved from first day PANSS-P = 18.26 to last day PANSS-P = 9.35 (F = 144.83; p < 0.001). Cognitive status showed a significant improvement from day 2 MMSE = 18.71 until day 7 MMSE = 24.06 (F = 96.56; p < 0.001), and the neurological subscale of the UKU side effect rating scale showed a significant improvement the last day with respect to baseline pretreatment level (F = 7.539; p = 0.01).

CONCLUSIONS

These results suggest a good response to amisulpride in the acute phase of delirium, although further randomized controlled studies must be performed.