Loss of IQ in the ICU brain injury without the insult

Evolution of Neuroimaging Findings in Severe COVID-19 Patients with Initial Neurological Impairment: An Observational Study

BACKGROUND AND OBJECTIVES

Cerebral complications related to the COVID-19 were documented by brain MRIs during the acute phase. The purpose of the present study was to describe the evolution of these neuroimaging findings (MRI and FDG-PET/CT) and describe the neurocognitive outcomes of these patients.

METHODS

During the first wave of the COVID-19 outbreak between 1 March and 31 May 2020, 112 consecutive COVID-19 patients with neurologic manifestations underwent a brain MRI at Strasbourg University hospitals. After recovery, during follow-up, of these 112 patients, 31 (initially hospitalized in intensive care units) underwent additional imaging studies (at least one brain MRI).

RESULTS

Twenty-three men (74%) and eight women (26%) with a mean age of 61 years (range: 18-79) were included. Leptomeningeal enhancement, diffuse brain microhemorrhages, acute ischemic strokes, suspicion of cerebral vasculitis, and acute inflammatory demyelinating lesions were described on the initial brain MRIs. During follow-up, the evolution of the leptomeningeal enhancement was discordant, and the cerebral microhemorrhages were stable. We observed normalization of the vessel walls in all patients suspected of cerebral vasculitis. Four patients (13%) demonstrated new complications during follow-up (ischemic strokes, hypoglossal neuritis, marked increase in the white matter FLAIR hyperintensities with presumed vascular origin, and one suspected case of cerebral vasculitis). Concerning the grey matter volumetry, we observed a loss of volume of 3.2% during an average period of approximately five months. During follow-up, the more frequent FDG-PET/CT findings were hypometabolism in temporal and insular regions.

CONCLUSION

A minority of initially severe COVID-19 patients demonstrated new complications on their brain MRIs during follow-up after recovery.

Delirium in Intensive Care

Purpose of Review

Delirium in the intensive care unit (ICU) has become increasingly acknowledged as a significant problem for critically ill patients affecting both the actual course of illness as well as outcomes. In this review, we focus on the current evidence and the gaps in knowledge.

Recent Findings

This review highlights several areas in which the evidence is weak and further research is needed in both pharmacological and non-pharmacological treatment. A better understanding of subtypes and their different response to therapy is needed and further studies in aetiology are warranted. Larger studies are needed to explore risk factors for developing delirium and for examining long-term consequences. Finally, a stronger focus on experienced delirium and considering the perspectives of both patients and their families is encouraged.

Summary

With the growing number of studies and a better framework for research leading to stronger evidence, the outcomes for patients suffering from delirium will most definitely improve in the years to come.

Design and rationale of the "Sedation strategy and cognitive outcome after critical illness in early childhood" study

There is increasing concern that sedatives commonly used during critical illness may be neurotoxic during the period of early brain development. The Sedation strategy and cognitive outcome after critical illness in early childhood (RESTORE-cognition) study is a prospective cohort study designed to examine the relationships between sedative exposure during pediatric critical illness and long-term neurocognitive outcomes. We assess multiple domains of neurocognitive function 2.5-5 years post-hospital discharge, at a single time point and depending on participant and clinician availability, in up to 500 subjects who had normal baseline cognitive function, were aged 2 weeks to 8 years at pediatric intensive care unit admission, and were enrolled in a cluster randomized controlled trial of a sedation protocol (the RESTORE trial; U01 HL086622 and HL086649). In addition, to provide comparable data on an unexposed group with similar baseline biological characteristics and environment, we are studying matched, healthy siblings of RESTORE patients. Our goal is to increase understanding of the relationships between sedative exposure, critical illness, and long-term neurocognitive outcomes in infants and young children by studying these subjects 2.5 to 5 years after their index hospitalization. This paper highlights the design challenges in conducting comprehensive neurocognitive assessment procedures across a broad age span at multiple testing centers across the United States. Our approach, which includes building interprofessional teams and novel cohort retention strategies, may be of help in future longitudinal trials.

The role of predictive coding in the pathogenesis of delirium

Delirium and dementia represent an emerging global crisis in healthcare. Attempts have been made to identify the pathognomonic feature that would make delirium stand out from dementia but unfortunately the global neural dysfunction of both disorders has made the establishment of a direct measurement difficult. Modern conceptualisations of delirium have been influenced by the assessment tools used to assess, detect, and analyse its complex and transient nature. Recent publication of the DSM-V criteria for delirium has marginally altered the previous DSM-IV criteria with a focus upon inattention with vague terms such as consciousness downplayed. Such an alteration has been found to be restrictive and thus impact upon delirium case identification. Although these findings are approximating the empirical state of delirium as measured by validated instruments, a more refined neuroscientifically informed phenomenological framework is required in order to enhance the theoretical understanding of delirium assessment and resolve these challenges. One such application is the predictive coding (PC) model, also known as the hierarchical Bayesian inference model, to interpreting delirium pathophysiology. Therefore, the aims of this paper are to 1) propose the hypothesis that delirium pathophysiology can be explained in terms of the PC model, 2) support this hypothesis by applying this model to current methods of assessing delirium phenomenology, particularly attention, and 3) outline a future programme of research to test many of the parameters of this application.

Evolution of Cerebral Atrophy in a Patient with Super Refractory Status Epilepticus Treated with Barbiturate Coma

Introduction. Status epilepticus is associated with neuronal breakdown. Radiological sequelae of status epilepticus include diffusion weighted abnormalities and T2/FLAIR cortical hyperintensities corresponding to the epileptogenic cortex. However, progressive generalized cerebral atrophy from status epilepticus is underrecognized and may be related to neuronal death. We present here a case of diffuse cerebral atrophy that developed during the course of super refractory status epilepticus management despite prolonged barbiturate coma. Methods. Case report and review of the literature. Case. A 19-year-old male with a prior history of epilepsy presented with focal clonic seizures. His seizures were refractory to multiple anticonvulsants and eventually required pentobarbital coma for 62 days and midazolam coma for 33 days. Serial brain magnetic resonance imaging (MRI) showed development of cerebral atrophy at 31 days after admission to our facility and progression of the atrophy at 136 days after admission. Conclusion. This case highlights the development and progression of generalized cerebral atrophy in super refractory status epilepticus. The cerebral atrophy was noticeable at 31 days after admission at our facility which emphasizes the urgency of definitive treatment in patients who present with super refractory status epilepticus. Further research into direct effects of therapeutic coma is warranted.

Observed medical and surgical complications of prolonged barbiturate coma for refractory status epilepticus

BACKGROUND

Refractory status epilepticus is often treated with third-line therapy, such as pentobarbital coma. However, its use is limited by side effects. Recognizing and preventing major and minor adverse effects of prolonged pentobarbital coma may increase good outcomes. This study retrospectively reviewed direct and indirect medical and surgical pentobarbital coma.

METHODS

Retrospective chart review of all patients with refractory status epilepticus treated with pentobarbital over a 1 year period at a large tertiary care center. We collected baseline data, EEG data, and complications that were observed.

RESULTS

Overall, nine patients [median age 46.4 (IQR 21.7, 75.5) years] were induced with pentobarbital coma median 11 (IQR 3, 33) days after seizure onset for a median of 9 (IQR 3.5, 45.4) days. A total of four to eight concurrent antiepileptics were tried prior to the pentobarbital coma. Phenobarbital, due to recurrence of seizures on weaning pentobarbital coma, was required in seven patients. Observed complications included peripheral neuropathy (77.8%), cerebral atrophy (33.3%), volume overload (44.4%), renal/metabolic (77.8%), gastrointestinal (66.6%), endocrine (55.6%), cardiac/hemodynamic/vascular (77.8%), respiratory (100%), and infectious (77.8%). The number of complications trended with duration of induced coma but was nonsignificant. Median ICU length of stay was 40 (IQR 28, 97.5) days. Overall, five patients were able to follow commands after a median 37 (IQR 25.5, 90) days from coma onset. There were eight patients that were discharged from hospital with three remaining in a prolonged unresponsive state. There was one patient that died prior to discharge.

CONCLUSIONS

This study highlights the high morbidity in patients with refractory status epilepticus requiring pentobarbital coma. Anticipating and addressing the indirect and direct complications in prolonged pentobarbital coma may improve survival and functional outcomes in patients with refractory status epilepticus.

[Septic encephalopathy]

Septic encephalopathy describes a diffuse cerebral dysfunction in association with sepsis. It is the most common cause of altered brain function in the intensive care unit setting but other causes have to be excluded. Alterations in the level of consciousness occur early and are common. Epileptic seizures may occur but asymmetric neurological findings are not typical. The pathophysiology of septic encephalopathy is diverse and not fully elucidated; however, perfusion abnormalities play an important role. Neuropathological findings are diffuse, widespread and often show features of ischemia and non-bacterial inflammation. Diagnostic procedures should exclude frequent differential diagnoses, such as stroke, meningitis or encephalitis. Cerebral computed tomography (CT) is usually unremarkable but magnetic resonance imaging (MRI) may reveal vasogenic edema in terms of a posterior reversible encephalopathy syndrome. Septic encephalopathy requires an adequate therapy of the sepsis syndrome but a specific therapy is not yet available.

The association between brain volumes, delirium duration, and cognitive outcomes in intensive care unit survivors: the VISIONS cohort magnetic resonance imaging study*

OBJECTIVE

Delirium duration is predictive of long-term cognitive impairment in intensive care unit survivors. Hypothesizing that a neuroanatomical basis may exist for the relationship between delirium and long-term cognitive impairment, we conducted this exploratory investigation of the associations between delirium duration, brain volumes, and long-term cognitive impairment.

DESIGN, SETTING, AND PATIENTS

A prospective cohort of medical and surgical intensive care unit survivors with respiratory failure or shock.

MEASUREMENTS

Quantitative high resolution 3-Tesla brain magnetic resonance imaging was used to calculate brain volumes at discharge and 3-month follow-up. Delirium was evaluated using the confusion assessment method for the intensive care unit; cognitive outcomes were tested at 3- and 12-month follow-up. Linear regression was used to examine associations between delirium duration and brain volumes, and between brain volumes and cognitive outcomes.

RESULTS

A total of 47 patients completed the magnetic resonance imaging protocol. Patients with longer duration of delirium displayed greater brain atrophy as measured by a larger ventricle-to-brain ratio at hospital discharge (0.76, 95% confidence intervals [0.10, 1.41]; p = .03) and at 3-month follow-up (0.62 [0.02, 1.21], p = .05). Longer duration of delirium was associated with smaller superior frontal lobe (-2.11 cm(3) [-3.89, -0.32]; p = .03) and hippocampal volumes at discharge (-0.58 cm(3) [-0.85, -0.31], p < .001)--regions responsible for executive functioning and memory, respectively. Greater brain atrophy (higher ventricle-to-brain ratio) at 3 months was associated with worse cognitive performances at 12 months (lower Repeatable Battery for the Assessment of Neuropsychological Status score -11.17 [-21.12, -1.22], p = .04). Smaller superior frontal lobes, thalamus, and cerebellar volumes at 3 months were associated with worse executive functioning and visual attention at 12 months.

CONCLUSIONS

These preliminary data show that longer duration of delirium is associated with smaller brain volumes up to 3 months after discharge, and that smaller brain volumes are associated with long-term cognitive impairment up to 12 months. We cannot, however, rule out that smaller preexisting brain volumes explain these findings.

Biomarkers associated with delirium in critically ill patients and their relation with long-term subjective cognitive dysfunction; indications for different pathways governing delirium in inflamed and noninflamed patients

Introduction

Delirium occurs frequently in critically ill patients and is associated with disease severity and infection. Although several pathways for delirium have been described, biomarkers associated with delirium in intensive care unit (ICU) patients is not well studied. We examined plasma biomarkers in delirious and nondelirious patients and the role of these biomarkers on long-term cognitive function.

Methods

In an exploratory observational study, we included 100 ICU patients with or without delirium and with ("inflamed") and without ("noninflamed") infection/systemic inflammatory response syndrome (SIRS). Delirium was diagnosed by using the confusion-assessment method-ICU (CAM-ICU). Within 24 hours after the onset of delirium, blood was obtained for biomarker analysis. No differences in patient characteristics were found between delirious and nondelirious patients. To determine associations between biomarkers and delirium, univariate and multivariate logistic regression analyses were performed. Eighteen months after ICU discharge, a cognitive-failure questionnaire was distributed to the ICU survivors.

Results

In total, 50 delirious and 50 nondelirious patients were included. We found that IL-8, MCP-1, procalcitonin (PCT), cortisol, and S100-β were significantly associated with delirium in inflamed patients (n = 46). In the noninflamed group of patients (n = 54), IL-8, IL-1ra, IL-10 ratio Aβ_1-42/40, and ratio Aβ_N-42/40 were significantly associated with delirium. In multivariate regression analysis, IL-8 was independently associated (odds ratio, 9.0; 95% confidence interval (CI), 1.8 to 44.0) with delirium in inflamed patients and IL-10 (OR 2.6; 95% CI 1.1 to 5.9), and Aβ_1-42/40 (OR, 0.03; 95% CI, 0.002 to 0.50) with delirium in noninflamed patients. Furthermore, levels of several amyloid-β forms, but not human Tau or S100-β, were significantly correlated with self-reported cognitive impairment 18 months after ICU discharge, whereas inflammatory markers were not correlated to impaired long-term cognitive function.

Conclusions

In inflamed patients, the proinflammatory cytokine IL-8 was associated with delirium, whereas in noninflamed patients, antiinflammatory cytokine IL-10 and Aβ_1-42/40 were associated with delirium. This suggests that the underlying mechanism governing the development of delirium in inflamed patients differs from that in noninflamed patients. Finally, elevated levels of amyloid-β correlated with long-term subjective cognitive-impairment delirium may represent the first sign of a (subclinical) dementia process. Future studies must confirm these results.

The study was registered in the Clinical Trial Register (NCT00604773).

Delirium: an emerging frontier in the management of critically ill children

Delirium is a syndrome of acute brain dysfunction that commonly occurs in critically ill adults and most certainly is prevalent in critically ill children all over the world. The dearth of information about the incidence, prevalence, and severity of pediatric delirium stems from the simple fact that there have not been well-validated instruments for routine delirium diagnosis at the bedside. This article reviewed the emerging solutions to this problem, including description of a new pediatric tool called the pCAM-ICU. In adults, delirium is responsible for significant increases in both morbidity and mortality in critically ill patients. The advent of new tools for use in critically ill children will allow the epidemiology of this form of acute brain dysfunction to be studied adequately, will allow clinical management algorithms to be developed and implemented following testing, and will present the necessary incorporation of delirium as an outcome measure for future clinical trials in pediatric critical care medicine.

A brief metacognition questionnaire for the elderly: comparison with cognitive performance and informant ratings the Cache County Study

OBJECTIVE

To examine the utility of a brief, metacognition questionnaire by examining its association with objective cognitive testing and informant ratings. We hypothesized that the association between self-ratings of change and both outcomes would be greater among individuals without dementia than among those with dementia.

METHODS

Participants were 535 persons without dementia and 152 with dementia from the Cache County Memory Study who had completed a metacognition questionnaire, two administrations of the Modified Mini-Mental State Exam (3 MS) and who had data on the Informant Questionnaire of Cognitive Decline in the Elderly (IQCODE). Cronbach's alpha was calculated as a measure of internal consistency of the metacognition questionnaire. Multiple regression was used to examine the relationship between metacognition and 3 MS change. Logistic regression was used to examine the relationship between metacognition and IQCODE ratings (no change vs. worse).

RESULTS

Cronbach's alpha was 0.75. Among individuals without dementia, metacognition significantly predicted 3 MS change (p = .027) and IQCODE ratings (OR = 4.0, 95% CI = 1.2-13.8, p = .029), suggesting consistency among measures. For those with dementia, there was a weak, inverse relationship between 3 MS change and metacognition (r = -0.16, p = .056). IQCODE ratings were not significantly associated with metacognition (p = .729). Degree of dementia severity did not modify the relationship between metacognition and either outcome (p > .05).

CONCLUSIONS

We demonstrated adequate internal consistency and evidence for validity of a brief metacognition questionnaire. The questionnaire may provide a useful adjunct to memory and functional assessments for assessing anosognosia in elderly populations.

Brain autopsy findings in intensive care unit patients previously suffering from delirium: a pilot study

PURPOSE

Delirium affects 50% to 80% of intensive care unit (ICU) patients and is associated with increased risk of mortality. Given the paucity of data reporting the neuropathologic findings in ICU patients experiencing delirium, the purpose of this pilot, hypothesis-generating study was to evaluate brain autopsies in ICU patients who suffered from delirium to explore possible neuroanatomical correlates.

MATERIALS AND METHODS

Using delirium databases at Vanderbilt University, we identified patients who had delirium in the ICU and subsequently died and received a brain autopsy during the same hospitalization. Brain autopsy reports were collected retrospectively on all 7 patients who met these criteria.

RESULTS

Patients' mean age was 55 (SD ± 8.4) years, and median number of days spent with delirium was 7 (± 5 interquartile range). In 6 (86%) of 7 patients, pathologic lesions normally attributed to hypoxia or ischemia were noted in the hippocampus, pons, and striatum. Hippocampal lesions represented the most common neuropathologic site of injury, present in 5 (71%) of 7 patients.

CONCLUSIONS

Hypoxic ischemic injury in multiple locations of the brain was a common finding. The biological plausibility of hippocampal lesions as a contributor to long-term cognitive impairment warrants postmortem investigation on a larger scale with comparison to patients not experiencing ICU delirium.

Is hypoglycaemia dangerous?

Tight glycaemic control (TGC) for patients treated in an intensive care unit ICU is associated with an increased risk for hypoglycaemia. Since hypoglycaemia mainly occurs in the sickest patients, no matter whether TGC is applied or not, it might be a marker for severity of illness or a harmful event in itself. Furthermore, it remains a matter of debate whether harmful effects of hypoglycaemia outbalance the clinical benefits of TGC. This review focusses on the clinical manifestations of hypoglycaemia in the critically ill and highlights its potential short- and long-term consequences specifically concerning neurocognitive function.

Acute respiratory distress syndrome, sepsis, and cognitive decline: a review and case study

The objective of this investigation is to review existing research pertaining to cognitive impairment and decline following critical illness and describe a case involving a 49-year-old female with sepsis and acute respiratory distress syndrome (ARDS) with no prior neurologic history who, compared to baseline neuropsychological test data, experienced dramatic cognitive decline and brain atrophy following treatment in the medical intensive care unit (ICU) at Vanderbilt University Medical Center. The patient participated in detailed clinical interviews and underwent comprehensive neuropsychological testing and neurological magnetic resonance imaging (MRI) at approximately 8 months and 3.5 years after ICU discharge. Compared to pre-ICU baseline test data, her intellectual function declined approximately 2 standard deviations from 139 to 106 (from the 99 to the 61 percentile) on a standardized intelligence test 8 months post-discharge, with little subsequent improvement. Initial diffusion tensor brain magnetic resonance imaging (DT-MRI) at the end of ICU hospitalization showed diffuse abnormal hyperintense areas involving predominately white matter in both hemispheres and the left cerebellum. A brain MRI nearly 4 years after ICU discharge demonstrated interval development of profound and generalized atrophy with sulcal widening and ventricular enlargement. The magnitude of cognitive decline experienced by ICU survivors is difficult to quantify due to the unavailability of pre-morbid neuropsychological data. The current case, conducted on a patient with baseline neuropsychological data, illustrates the trajectory of decline occurring after critical illness and ICU-associated brain injury with marked atrophy and concomitant cognitive impairments.

Delirium: an emerging frontier in the management of critically ill children

The objectives of this article are (1) to introduce pediatric delirium and provide understanding of acute brain dysfunction with its classification and clinical presentations (2) to understand how delirium is diagnosed and discuss current modes of delirium diagnosis in the critically ill adult population and translation to pediatrics (3) to understand the prevalence and prognostic significance of delirium in the adult and pediatric critically ill population (4) to discuss the pathophysiology of delirium as currently understood, and (5) to provide general management guidelines for delirium.

Delirium in the intensive care unit

Delirium is a common manifestation of acute brain dysfunction in critically ill patients with prevalence as high as 75%. In the last years there has been a progressive increase of publications regarding intensive care (ICU) delirium, acknowledging its importance. The occurrence of delirium in ICU is related to more adverse outcomes including self-extubation and removal of catheters, prolonged hospitalization, increased costs, higher mortality, and potentially, long-term cognitive impairment. The pathophysiology explaining the processes subtending the development of delirium is still elusive, though several theories have been discussed. It is known that different risk factors are associated with delirium in the ICU. Patients in ICU frequently receive medications to treat pain and to ensure sedation, but an association between these drugs and delirium has been shown. Therefore, this pharmacological exposure should be modified to reduce the risk factors. Giving the multifactorial genesis of delirium, multicomponent interventions to prevent delirium developed in non-ICU settings can be adapted to critically ill patients with the purpose of reducing the incidence. When delirium is diagnosed the use of typical and atypical antipsychotics may be effective for its treatment. Future studies should evaluate target interventions to prevent delirium in the ICU.

Types of brain dysfunction in critical illness

Cerebral dysfunction and injury in the ICU presents as focal neurologic deficits, seizures, coma, and delirium. These syndromes may result from a primary brain insult, such as stroke or trauma, but commonly are a complication of a systemic insult, such as cardiac arrest, hypoxemia, sepsis, metabolic derangements, and pharmacologic exposures. Many survivors of critical illness have cognitive impairment, which is believed to underlie the poor long-term functional status and quality of life observed in many critical illness survivors. Although progress has been made in characterizing the epidemiology of cerebral dysfunction in the ICU, more research is needed to elucidate underlying mechanisms that might represent targets for therapeutic intervention.

Mechanisms of neurologic failure in critical illness

Critical illness frequently is associated with neurologic failure that may involve the central and peripheral nervous systems. Central nervous system failure is associated with a spectrum of neurobehavioral changes including delirium, coma, and long-term cognitive dysfunction. Peripheral neurologic failure, or critical illness neuromuscular abnormalities, is suggested by diffuse arreflexic weakness and protracted respiratory insufficiency, and may also persist long after the acute hospitalization. While the burden of neurological disease complicating critical illness is considerable, preventive or therapeutic options are limited. This article provides an overview of research evaluating the relationship between critical illness and neurologic function, with a special emphasis on underlying mechanisms.

Pathophysiology of delirium in the intensive care unit

Delirium, or acute brain dysfunction, is a life-threatening global disturbance in cognitive functioning that frequently manifests in critically ill patients. This review examines the current status of knowledge regarding the pathophysiology of delirium in the ICU, in particular, evaluating the role of iatrogenic factors such as sedatives and analgesic administration in brain dysfunction. This hypothesis is considered along with several other plausible mechanisms of ICU delirium, including sepsis, postoperative cognitive dysfunction, and changes in biomarkers and neurotransmitters. The review concludes by highlighting potential future directions in molecular genetics for the elucidation of delirium and its long-term consequences.