Electroencephalographic Measures of Delirium in the Perioperative Setting: A Systematic Review.

Postoperative delirium (POD) is frequent in older adults and is associated with adverse cognitive and functional outcomes. In the last several decades, there has been an increased interest in exploring tools that easily allow the early recognition of patients at risk of developing POD. The electroencephalogram (EEG) is a widely available tool used to understand delirium pathophysiology, and its use in the perioperative setting has grown exponentially, particularly to predict and detect POD. We performed a systematic review to investigate the use of EEG in the pre-, intra-, and postoperative settings. We identified 371 studies, and 56 met the inclusion criteria. A range of techniques was used to obtain EEG data, from limited 1-4 channel setups to complex 256-channel systems. Power spectra were often measured preoperatively, yet the outcomes were inconsistent. During surgery, the emphasis was primarily on burst suppression (BS) metrics and power spectra, with a link between the frequency and timing of BS, and POD. The EEG patterns observed in POD aligned with those noted in delirium in different contexts, suggesting a reduction in EEG activity. Further research is required to investigate preoperative EEG indicators that may predict susceptibility to delirium.

Prodromal Dementia with Lewy Bodies: A Case Series of the 3 Prodromal Types from Clinical Practice.

Prodromal dementia with Lewy bodies (DLB) refers to a state prior to the onset of dementia with clinical signs or symptoms that may indicate the future development of DLB. Prodromal symptoms can include not only cognitive deficits but also a mix of clinical features including sleep disorders, autonomic dysfunction, and neuro-psychiatric disturbances. While diagnostic criteria for the subtypes of prodromal DLB were recently published, they are largely used in research settings. However, these criteria have important implications for clinical practice. Recognition of prodromal DLB stages can lead to identifying deficits sooner, improved patient and family counseling, and advance care planning. This case series presents examples of the 3 subtypes of prodromal DLB - mild cognitive impairment onset, delirium onset, and psychiatric onset - to help clinicians identify individuals who may be on a trajectory to develop DLB.

Sex, sepsis and the brain: defining the role of sexual dimorphism on neurocognitive outcomes after infection.

Sexual dimorphisms exist in multiple domains, from learning and memory to neurocognitive disease, and even in the immune system. Male sex has been associated with increased susceptibility to infection, as well as increased risk of adverse outcomes. Sepsis remains a major source of morbidity and mortality globally, and over half of septic patients admitted to intensive care are believed to suffer some degree of sepsis-associated encephalopathy (SAE). In the short term, SAE is associated with an increased risk of in-hospital mortality, and in the long term, has the potential for significant impairment of cognition, memory, and acceleration of neurocognitive disease. Despite increasing information regarding sexual dimorphism in neurologic and immunologic systems, research into these dimorphisms in sepsis-associated encephalopathy remains critically understudied. In this narrative review, we discuss how sex has been associated with brain morphology, chemistry, and disease, sexual dimorphism in immunity, and existing research into the effects of sex on SAE.

American Delirium Society 2022 Year in Review: Highlighting the Year's Most Impactful Delirium Research.

Background: Since 2015, the American Delirium Society (ADS) Research Committee has conducted an annual survey of the delirium literature for presentation in its year-in-review session. Our objectives were to describe the review process used for the 2021-2022 and to summarise the selected publications. Methods: Each member of the ADS Research Committee nominated up to 6 publications considered to be the most impactful primary delirium research published from September 1, 2021, to July 31, 2022. The 24 nominated studies were divided into three categories balanced by number of articles: medical intervention trials, non-medical intervention trials, and delirium detection/basic science studies. Each ADS Research Committee member ranked all studies in their assigned category for methodological rigor and for impact, each being scored as 0-10, for a total score of 0-20. It was decided a priori to select the top three highest-scoring articles in each category for presentation, with ties adjudicated by Committee consensus. Results: Nineteen Research Committee members served as reviewers. Scores for each category were similar: medical interventions mean (standard deviation) 12.8 (1.1), non-medical interventions 13.1 (1.1), and detection/basic science 12.6 (1.0). We summarise the results of the papers presented in the 2022 ADS year-in-review session. Conclusion: The diversity of studies presented for the 2022 ADS year-in-review session illustrates the breadth of the delirium field and the growing number of clinical trials. The dissemination of publications across a broad, diverse array of journals provides further justification of the need for delirium-specific journals.

Vertical pseudoneglect: Sensory-attentional versus action-intentional.

INTRODUCTION: Healthy persons demonstrate an upward bias on the vertical-line bisection test (vertical or "altitudinal" pseudoneglect). This bias might be sensory-attentional or action-intentional in origin. To test the action-intention hypothesis, we analyze whether the direction of action has an effect on altitudinal pseudoneglect. METHODS: Twenty-four healthy right-handed adults performed vertical-line bisection on an apparatus designed to distinguish the effects of sensory-attention and action-intention. Depending on hand placement, participants estimated line midpoints with a marker that moved in the same (congruent) or opposite (incongruent) direction as their hand movements. Two binary factors - hand movement in the upward versus downward direction and congruent vs incongruent hand movements - produced four conditions. RESULTS: There was upward deviation from the midline across all conditions. Bisections in the incongruent condition were higher than in the congruent condition. Bisections were also higher with upward hand movements than with downward hand movements. There was not a significant interaction between these factors. CONCLUSIONS: These results suggest that vertical pseudoneglect is primarily influenced by the allocation of allocentric attention, rather than action-intention. However, action-perceptual spatial incongruence increased this deviation. Perhaps the incongruent condition requires greater allocation of attention, but further exploration is needed. Additionally, these results suggest that visual attention follows the direction of motor action. Future studies of visual attention should consider the potential influence of this factor.

Neuropsychiatric profiles in dementia.

We compared patterns of neuropsychiatric symptoms across 4 dementia types [Alzheimer disease (AD), vascular dementia (VAD), dementia with Lewy bodies (DLB), and Parkinson disease dementia], and 2 mixed groups (AD/VAD and AD/DLB) in sample of 2,963 individuals from the National Alzheimer's Coordinating Center Uniform Data Set between September 2005 and June 2008. We used confirmatory factor analysis to compare neuropsychiatric symptom severity ratings made by collateral sources on the Neuropsychiatric Inventory Questionnaire for people with Clinical Dementia Rating scores of 1 or higher. A 3-factor model of psychiatric symptoms (mood, psychotic, and frontal) was shared across all dementia types. Between-group comparisons revealed unique neuropsychiatric profiles by dementia type. The AD group had moderate levels of mood, psychotic, and frontal symptoms whereas VAD exhibited the highest levels and Parkinson disease dementia had the lowest levels. DLB and the mixed dementias had more complex symptom profiles. Depressed mood was the dominant symptom in people with mild diagnoses. Differing psychiatric symptom profiles provide useful information regarding the noncognitive symptoms of dementia.