Search

Background Delirium has conventionally been considered a disorder of consciousness. Alertness and arousal are used as surrogates in clinical practice but are insufficient for the purposes of a more dimensional assessment of consciousness. We present a process of development and validation of candidate measures of phenomenal consciousness that could be applied to the diagnosis of delirium. Methods First, a narrative review of available instruments in the fields of phenomenal consciousness, including prereflective consciousness, the phenomenal-sensed experience and reflective thought, was undertaken. Eligibility of tools in the context of applicability to delirium was based upon objectivity in test interpretation and the requirement for tester administration. Second, where there was a gap in suitable cognitive tools, new items were derived using the silent generation technique. A process of face and construct validity using a diverse panel of experts was performed, and readability was evaluated. Results 814 articles were screened from the literature review. Fourteen candidate tools were reported from the three domains of phenomenal consciousness. One of these met the eligibility criteria for a delirium assessment. Fifty-seven new tests of phenomenal consciousness were identified. After a process of item reduction, a total of 26 individual tests were identified. After content validity, 22 of the 26 items were retained. The scale average content validity index was 0.89. The agreement between raters was between 80% and 97%. 100% of responses for face validity were rated as positive. Flesch Reading Ease Score was 91.6 (very easy to read). Conclusions Candidate measures of phenomenal consciousness are described, and early validity studies are promising. [ABSTRACT FROM AUTHOR]

Background recognition of the multifactorial causes of delirium represents a clinical challenge. Objectives to develop and show proof of principle of a diagnostic support tool (DST) for identification of causes of delirium. Methods stage 1—development of the aetiology in delirium-diagnostic support tool (AiD-DST); stage 2—validation of the AiD-DST against reference standard diagnosis, based on clinical assessment from two independent consultant geriatricians. Results a series of eight steps AiD-DST were formulated by an expert group to identify possible causes of delirium. Forty inpatients admitted to a general medical unit with a consultant physician/geriatrician diagnosis of delirium were recruited, consented and reviewed against the AiD-DST. Mean age was 85.1 (standard deviation 7.9) years and 26 (65%) of participants were female. Participants had multiple chronic co-morbidities [median Charlson Comorbidity Index 7; interquartile range (IQR 6–9)] and median number of medications was 8 (IQR 6–11.75). Median number of causes of delirium detected on AiD-DST was 3 (IQR 3–4) versus 5 (IQR 3–6) using the reference standard diagnosis, with sensitivity of 88.8% (95% confidence interval, 81.6–93.9%) and specificity of 71.8% (63–79.5%). Conclusions the aetiology in delirium DST shows promise in the identification of cause(s) in delirium. [ABSTRACT FROM AUTHOR]

Background: Dysfunction of the cholinergic basal forebrain (BF) neurotransmitter system, including cholinergic axon denervation of the cortex, plays an important role in cognitive decline and dementia. The association of cortical cholinergic denervation with diverse cognitive profiles in dementia, particularly at early stages, has not yet been fully explored. We assessed the relationship of cholinergic denervation in the cortex measured using 18F‐fluoroethoxybenzovesamicol (FEOBV) with cognitive decline at an early stage of dementia. Method: Participants (8 with mild cognitive impairment (MCI) and 10 cognitively unimpaired (CU) controls, aged 60‐86, 55.6% female, MMSE = 28.7±1.5) underwent neuropsychological assessment and FEOBV PET imaging. The neuropsychological battery of tests included measures of memory, executive function, attention and language. Domain‐specific composite scores were calculated by averaging z‐scores of the related tests or subtasks within a domain. FEOBV images were co‐registered to the concurrent structural MRI and normalised to the supratentorial white matter reference region resulting in a standardized uptake value ratio (SUVR). Voxel‐wise analysis was performed on normalised FEOBV images to investigate associations with clinical diagnosis and domain‐specific cognitive performance. Voxel‐based morphometry was also performed to rule out differences in brain morphology. All analyses were corrected for age, sex and total intracranial volume and adjusted for multiple comparisons. Result: The MCI group showed significantly lower global FEOBV SUVR in the cortex although only a focal cluster of reductions near the right middle temporal gyrus was found in the voxel‐wise comparisons. When associations with cognitive performance profiles were assessed in the full cohort, regional positive correlations were found between FEOBV SUVR and cognitive scores across different domains (Figure 1), although these did not include memory. For executive functioning, widespread correlation patterns were observed across both cortical and subcortical regions. Moreover, overlapping profiles were identified for all three cognitive domains of executive function, attention and language, which covered the anterior cingulate gyrus, olfactory cortex, calcarine cortex, middle temporal gyrus and caudate nucleus. Conclusion: We have demonstrated that the topographic profile of FEOBV retention correlated with reduced cognitive performance in different domains, suggesting that reduced cortical cholinergic terminal integrity is an important pathological feature of cognitive decline. [ABSTRACT FROM AUTHOR]