The Association Between Delirium and Cognitive Decline: A Review of the Empirical Literature

Delirium is a common neurobehavioral syndrome that occurs across health care settings which is associated with adverse outcomes, including death. There are limited data on long-term cognitive outcomes following delirium. This report reviews the literature regarding relationships between delirium and cognitive impairment. Psych Info and Medline searches and investigation of secondary references for all English language articles on delirium and subsequent cognitive impairment were carried out. Nine papers met inclusion criteria and documented cognitive impairment in patients following delirium. Four papers reported greater cognitive impairment among patients with delirium than matched controls. Four papers reported higher incidence of dementia in patients with a history of delirium. One study found 1 of 3 survivors of critical illness with delirium developed cognitive impairment. The evidence suggests a relationship between delirium and cognitive impairment, although significant questions remain regarding the nature of this association. Additional research on delirium-related effects on long-term cognitive outcome is needed.     

轻度认知损伤的语义记忆研究述评

轻度认知损伤（Mild cognitive impairment,MCI）是介于正常老化与痴呆之间的过渡阶段,表现为与年龄和教育程度不相称的认知功能减退。本文回顾了近期有关MCI语义记忆的研究,分析比较了各研究的实验任务及结果,得出MCI患者存在一定程度的由多种原因造成的语义记忆损伤,语义记忆测验对MCI的早期筛查和转归预测有重要作用。最后指出将来的研究需要将包括语义记忆成分在内的多种认知测验相结合,以便及早发现有可能发展为痴呆的危险个体并开展相应干预。     

Screening for cognitive impairment in an Australian aged care assessment team as part of comprehensive geriatric assessment

Accurate detection of mild cognitive impairment (MCI) is important to stratify and address risk. Yet, few short cognitive screening instruments are validated for this. . In Australia, all clients referred to an Aged Care Assessment Team (ACAT) receive comprehensive geriatric assessment (CGA) including the Standardized Mini-Mental State Examination (SMMSE). We compared the accuracy of the quick mild cognitive impairment (Qmci) screen to the SMMSE in 283 participants: 195 with dementia, 47 with MCI, and 41 with subjective cognitive decline (SCD) in an Australian community-based ACAT. Both had similar accuracy in identifying dementia, AUC of 0.86 for the Qmci versus 0.93 for the SMMSE (p = 0.10), but the Qmci was more accurate than the SMMSE in differentiating MCI from SCD, AUC of 0.84 versus 0.71, respectively, p = 0.046. These suggest that the new, short (3–5 min) Qmci screenis appropriate for use in an ACAT or other units conducting CGA.     

Visual associations to retrieve episodic memory across healthy elderly,mild cognitive impairment,and patients with Alzheimer’s disease

Episodic memory tests need to determine the degree to which patients with moderate to severe memory deficits can still benefit from retrieval support. Especially in the case of Alzheimer’s disease (AD), this may support health care to be more closely aligned with patients’ memory capacities. We investigated whether the different measures of episodic memory of the Visual Association Test-Extended (VAT-E) can provide a more detailed and informative assessment on memory disturbances across a broad range of cognitive decline, from normal to severe impairment as seen in AD, by examining differences in floor effects. The VAT-E consists of 24 pairs of black-and-white line drawings. In a within-group design, we compared score distributions of VAT-E subtests in healthy elderly controls, mild cognitive impairment (MCI), and AD (n = 144), as well as in relation to global cognitive impairment. Paired associate recall showed a floor effect in 41% of MCI patients and 62% of AD patients. Free recall showed a floor effect in 73% of MCI patients and 84% of AD patients. Multiple-choice cued recognition did not show a floor effect in either of the patient groups. We conclude that the VAT-E covers a broad range of episodic memory decline in patients. As expected, paired associate recall was of intermediate difficulty, free recall was most difficult, and multiple-choice cued recognition was least difficult for patients. These varying levels of difficulty enable a more accurate determination of the level of retrieval support that can still benefit patients across a broad range of cognitive decline.     

Assessing cognitive impairment in Indigenous Australians: Re‐evaluation of the Kimberley Indigenous Cognitive Assessment in Western Australia and the Northern Territory

The Kimberley Indigenous Cognitive Assessment (KICA) was initially developed and validated as a culturally appropriate dementia screening tool for older Indigenous people living in the Kimberley. This paper describes the re‐evaluation of the psychometric properties of the cognitive section (KICA‐Cog) of this tool in two different populations, including a Northern Territory sample, and a larger population‐based cohort from the Kimberley. In both populations, participants were evaluated on the KICA‐Cog tool, and independently assessed by expert clinical raters blinded to the KICA scores, to determine validity and reliability of dementia diagnosis for both groups. Community consultation, feedback and education were integral parts of the research. for the Northern Territory sample, 52 participants were selected primarily through health services. Sensitivity was 82.4% and specificity was 87.5% for diagnosis of dementia, with area under the curve (AUC) of .95, based on a cut‐off score of 31/32 of a possible 39. for the Kimberley sample, 363 participants from multiple communities formed part of a prevalence study of dementia. Sensitivity was 93.3% and specificity was 98.4% for a cut‐off score of 33/34, with AUC = .98 (95% confidence interval: 0.97–0.99). There was no education bias found. The KICA‐Cog appears to be most reliable at a cut‐off of 33/39.     

Relative absence of neuropsychological deficit in patients with low grade astrocytomas

Given the current accuracy and precision of modern brain imaging technology, there is presumed to be little utility in neuropsychological assessment procedures in patients with brain tumors. The primary exposure of many clinical neuropsychologists to patients with brain tumors is during their training, in the form of didactic classroom activities, such as reviewing the brain tumor cases of early investigators in the field. Historically, these brain tumors were the more aggressive and destructive tumors, such as grade III and IV astrocytomas, that could be identified with pre CT and pre MRI technology. With current imaging technology, low grade tumors that might previously have gone undiagnosed for years can be detected and patients followed over time. This series of cases represents documentation of the very unique neuropsychological status of patients with relatively slow growing, infiltrative brain tumors classified as grade II astrocytomas. The potential relevance of neuropsychological assessment for such cases is discussed.     

Contextual Factors for Research on Psychological Therapies for Aboriginal Australians

This paper is to provide a commentary to Can cognitive behavioural therapy (CBT) be effective for Aboriginal Australians? Perspectives of Aboriginal practitioners trained in CBT. It is inspiring that this study has found that CBT can play a useful role in therapy for Aboriginal and Torres Strait Islander people but the outcomes need to be considered with caution. CBT can provide a useful tool when working with Aboriginal and Torres Strait Islander people, but in itself is not adequate for a number of reasons. Firstly, it is not culturally responsive but can be part of an approach that might be culturally appropriate. The authors are compelled at this point to give a history of mental health and Aboriginal and Torres Strait Islander people to provide a background context to the discussion and to illustrate why some psychological approaches such as CBT can only ever be part of the tools that might be used in a broader framework, that is required to address and strengthen Aboriginal and Torres Strait Islander people's well‐being.     

How impaired is too impaired? Exploring futile neuropsychological test patterns as a function of dementia severity and cognitive screening scores

Some older adults cannot meaningfully participate in the testing portion of a neuropsychological evaluation due to significant cognitive impairments. There are limited empirical data on this topic. Thus, the current study sought to provide an operational definition for a futile testing profile and examine cognitive severity status and cognitive screening scores as predictors of testing futility at both baseline and first follow-up evaluations. We analysed data from 9,263 older adults from the National Alzheimer’s Coordinating Center Uniform Data Set. Futile testing profiles occurred rarely at baseline (7.40%). There was a strong relationship between cognitive severity status and the prevalence of futile testing profiles, χ²(4) = 3559.77, p < .001. Over 90% of individuals with severe dementia were unable to participate meaningfully in testing. Severity range on the Montreal Cognitive Assessment (MoCA) also demonstrated a strong relationship with testing futility, χ²(3) = 3962.35, p < .001. The rate of futile testing profiles was similar at follow-up (7.90%). There was a strong association between baseline dementia severity and likelihood of demonstrating a futile testing profile at follow-up, χ²(4) = 1513.40, p < .001. Over 90% of individuals with severe dementia, who were initially able to participate meaningfully testing, no longer could at follow-up. Similarly, there was a strong relationship between baseline MoCA score band and likelihood of demonstrating a futile testing profile at follow-up, χ²(3) = 1627.37, p < .001. Results can help to guide decisions about optimizing use of limited neuropsychological assessment resources.     

Dysexecutive syndrome in Parkinson’s disease: the GREFEX study

The objectives of this study were to characterize the frequencies and profiles of behavioral and cognitive dysexecutive syndromes in PD (based on validated battery and diagnostic criteria) and to develop a shortened diagnostic battery. Eighty-eight non-demented patients with a diagnosis of PD were examined with an executive validated battery. Using a validated framework, the patients’ test results were interpreted with respect to normative data from 780 controls. A dysexecutive syndrome was observed in 80.6% of the patients [95% confidence interval: 71.1–90.1]. The dysexecutive profile was characterized by prominent impairments in deduction, flexibility, inhibition and initiation in the cognitive domain, and by global hypoactivity with apathy and hyperactivity in the behavioral domain. This finding implies that patients with PD should be assessed with cognitive tests and a validated inventory for behavioral dysexecutive syndromes. A shortened battery (based on three cognitive tests and three behavioral domains) provided high diagnostic accuracy.     

Neuropsychological function in a group of patients 25 years after sustaining minor head injuries as children and adolescents

Previous studies suggest that neuropsychological impairment following mild to moderate pediatric head injury may become persistent and interrupt the normal course of intellectual development. In this study 45 subjects were assessed with a standardized neuropsychological test battery 25 years after sustaining mild to moderate head injury as children. Although the group scores in the normal range, significant relations between head injury severity and current neuropsychological function were found. The most important predictor of poor outcome was length of PTA at injury, EEG pathology, and loss of consciousness at injury. No significant influence of pre- and post-injury risk factors on current neuropsychological function was evident. The findings support the view that complicated mild and moderate paediatric head injury may heighten the risk of developing subtle neuropsychological problems later in life.     

Neuropsychological subgroups of adolescents with conduct disorder

Närhi, V., Lehto‐Salo, P., Ahonen, T. & Marttunen, M. (2010). Neuropsychological subgroups of adolescents with conduct disorder. Scandinavian Journal of Psychology, 51, 278–284. In group‐level studies adolescents with conduct disorder (CD) have been found to have deficiencies in verbal and executive functions. Teichner and Golden (2000) addressed the neuropsychological heterogeneity of CD, and hypothesized the existence of six neuropsychologically different subgroups. We used that theoretical basis to identify subgroups among 77 adolescents with CD and 48 controls. Among subjects with CD we identified subjects with no, diffuse, verbal and executive function deficits, but none with specific memory or visuo‐spatial deficits. In total, neuropsychological deficits altogether were more common among subjects with CD relative to controls, as were specific verbal deficits. Subgroups did not differ in gender distribution, comorbidity of psychiatric disorders, type or severity of CD, or number of psychosocial risk factors. Among subjects with CD, learning disabilities were common. CD is neuropsychologically a heterogeneous disorder, and neuropsychological deficits should be taken into account in assessing and planning interventions for adolescents with CD.     

Cognitive Event-Related Potentials in Neuropsychological Assessment

Neuropsychology is a behavioral approach to studying the brain, and an integration of neuropsychology with on-line processing measures of brain function is important for advancing the understanding of brain–behavior relationships. Cognitive event-related potentials (ERPs) are on-line processing measures that are of interest to neuropsychologists because they are linked to familiar neuropsychological test paradigms and because they have reached a degree of standardization sufficient to make them applicable in individual assessment. A selective review of cognitive ERPs is given, focusing on studies of attention in the oddball paradigm and arguing that an adequate assessment of attention is basic in understanding higher order cognitive functions. General principles for using ERP data to supplement and clarify neuropsychological analysis are discussed, and available evidence on dementia and traumatic head injury is reviewed. It is concluded that ERPs are a useful supplement to neuropsychological assessment. Although diagnostic use of ERPs must be guarded because of limited standardization and validation, information-processing analysis with ERPs may aid significantly in interpretation of behavioral data.     

活动参与在认知损害中的延缓作用

认知损害有关的病理机制、危险因素研究由来已久,但尚未找到有效治疗认知损害的途径,认知损害的保护性因素研究进而成为研究者们关注的热点。前人的研究显示活动参与对认知损害具有积极的影响,可能是认知损害的重要保护性因素,但活动参与对认知损害的影响机制以及各活动之间存在的交互作用仍不明确。未来的研究可着重探讨不同活动类型及其交互作用同认知损害的关系,并分析活动参与对认知损害起保护作用的公共因子。