Paula V. Nunes

CAMcog as a screening tool for diagnosis of mild cognitive impairment and dementia in a Brazilian clinical sample of moderate to high education

The CAMCOG is a brief neuropsychological battery designed to assess global cognitive function and ascertain the impairments that are required for the diagnosis of dementia. To date, the cut‐off scores for mild cognitive impairment (MCI) have not been determined. Given the need for an earlier diagnosis of mild dementia, new cut‐off values are also necessary, taking into account cultural and educational effects.

Post-Operative Delirium Is Associated with Poor Cognitive Outcome and Dementia

The objective of the present study is to evaluate the association between the occurrence of delirium and the cognitive outcome in elderly subjects. Hospital files of 572 patients who underwent hip or knee replacement between 1998 and 2004 were examined. A sample of 90 elderly subjects (31 with evidence of post-operative delirium), non-demented at baseline, was screened for cognitive decline and dementia. Diagnosis of dementia was highly associated with the occurrence of delirium. The relative risk for the diagnosis of dementia among subjects with previous history of delirium, according to the IQcode screening, was 10.5 (95% CI: 3.3–33.2). Such patients had a significantly higher mean IQcode score (3.75) as compared to controls (3.1; p < 0.001). Cognitive functions most affected in these patients were memory, orientation and abstract thinking. We conclude that the occurrence of post-operative delirium in cognitively unimpaired elderly subjects is associated with a worse cognitive outcome and an increased risk of dementia.

Mild cognitive impairment: cognitive screening or neuropsychological assessment?

OBJECTIVE To describe the neuropsychological profile of mild cognitive impairment subtypes (amnestic, non-amnestic and multiple-domain) of a clinical sample. We further address the diagnostic properties of the Mini-Mental State Examination and the Cambridge Cognitive Examination for the identification of the different mild cognitive impairment subtypes in clinical practice. METHOD Cross-sectional clinical and neuropsychological evaluation of 249 elderly patients attending a memory clinic at a university hospital in Sao Paulo, Brazil. RESULTS The performance of patients with mild cognitive impairment was heterogeneous across the different subtests of the neuropsychological battery, with a trend towards an overall worse performance for amnestic (particularly multiple domain) mild cognitive impairment as compared to non-amnestic subtypes. Screening tests for dementia (Mini-Mental State Examination and Cambridge Cognitive Examination) adequately discriminated cases of mild Alzheimers disease from controls, but they were not accurate to discriminate patients with mild cognitive impairment (all subtypes) from control subjects. CONCLUSIONS The discrimination of mild cognitive impairment subtypes was possible only with the aid of a comprehensive neuropsychological assessment. It is necessary to develop new strategies for mild cognitive impairment screening in clinical practice.

Diagnostic transitions in mild cognitive impairment subtypes

BACKGROUND At least for a subset of patients, the clinical diagnosis of mild cognitive impairment (MCI) may represent an intermediate stage between normal aging and dementia. Nevertheless, the patterns of transition of cognitive states between normal cognitive aging and MCI to dementia are not well established. In this study we address the pattern of transitions between cognitive states in patients with MCI and healthy controls, prior to the conversion to dementia. METHODS 139 subjects (78% women, mean age, 68.5 +/- 6.1 years; mean educational level, 11.7 +/- 5.4 years) were consecutively assessed in a memory clinic with a standardized clinical and neuropsychological protocol, and classified as cognitively healthy (normal controls) or with MCI (including subtypes) at baseline. These subjects underwent annual reassessments (mean duration of follow-up: 2.7 +/- 1.1 years), in which cognitive state was ascertained independently of prior diagnoses. The pattern of transitions of the cognitive state was determined by Markov chain analysis. RESULTS The transitions from one cognitive state to another varied substantially between MCI subtypes. Single-domain MCI (amnestic and non-amnestic) more frequently returned to normal cognitive state upon follow-up (22.5% and 21%, respectively). Among subjects who progressed to Alzheimers disease (AD), the most common diagnosis immediately prior conversion was multiple-domain MCI (85%). CONCLUSION The clinical diagnosis of MCI and its subtypes yields groups of patients with heterogeneous patterns of transitions between one given cognitive state to another. The presence of more severe and widespread cognitive deficits, as indicated by the group of multiple-domain amnestic MCI may be a better predictor of AD than single-domain amnestic or non-amnestic deficits. These higher-risk individuals could probably be the best candidates for the development of preventive strategies and early treatment for the disease.

Neuropsychological Profile of Brazilian Older Adults with Heterogeneous Educational Backgrounds

Education significantly impacts cognitive performance of older adults even in the absence of dementia. Some cognitive tests seem less vulnerable to the influence of education and thus may be more suitable for cognitive assessment of older adults with heterogeneous backgrounds. The objective of this study was to investigate which tests in a cognitive battery were less influenced by educational levels in a sample of cognitively unimpaired older Brazilians. In addition, we evaluated the impact of very high educational levels on cognitive performance. The cognitive battery consisted of the Mini Mental State Examination (MMSE), Cambridge Cognitive Test (CAMCOG), Clock Drawing Test, Short Cognitive Performance Test (SKT), Rivermead Behavioural Memory Test (RBMT), Fuld Object Memory Evaluation (FOME), Verbal Fluency Test (VF) fruit category, Trail Making Test A and B, WAIS-R Vocabulary, and Block Design. Education did not exert a significant influence on the RBMT, FOME, and VF (p < .05). Subjects with very high educational levels had similar performance on the latter tests when compared with those with intermediate and low levels of education. In conclusion, the RBMT, FOME, and VF fruit category seem to be appropriate tools for the assessment of cognitive function in elderly Brazilians with varying degrees of educational attainment.

Neuropathological relationship between major depression and dementia: A hypothetical model and review.

Major depression (MDD) is a chronic psychiatric condition in which patients often show increasing cognitive impairment with recurring episodes. Neurodegeneration may play an important component in the pathogenesis of MDD associated with cognitive complaints. In agreement with this, patients with MDD show decreased brain volumes in areas implicated in emotional regulation and cognition, neuronal and glial cell death as well as activation of various pathways that can contribute to cell death. Therefore, the aim of this review is to provide an integrative overview of potential contributing factors to neurodegeneration in MDD. Studies have reported increased neuronal and glial cell death in the frontal cortex, amygdala, and hippocampus of patients with MDD. This may be due to decreased neurogenesis from lower levels of brain-derived neurotrophic factor (BDNF), excitotoxicity from increased glutamate signaling, and lower levels of gamma-aminobutyric acid (GABA) signaling. In addition, mitochondrial dysfunction and oxidative stress are found in similar brain areas where evidence of excitotoxicity has been reported. Also, levels of antioxidant enzymes were reported to be increased in patients with MDD. Inflammation may also be a contributing factor, as levels of inflammatory cytokines were reported to be increased in the prefrontal cortex of patients with MDD. While preliminary, studies have also reported neuropathological alterations in patients with MDD. Together, these studies suggest that lower BDNF levels, mitochondrial dysfunction, oxidative stress, inflammation and excitotoxicity may be contributing to neuronal and glial cell death in MDD, leading to decreased brain volume and cognitive dysfunction with multiple recurrent episodes. This highlights the need to identify specific pathways involved in neurodegeneration in MDD, which may elucidate targets that can be treated to ameliorate the effects of disease progression in this disorder.

Psychometric characteristics of the Rivermead Behavioural Memory Test (RBMT) as an early detection instrument for dementia and mild cognitive impairment in Brazil.

BACKGROUND The Rivermead Behavioural Memory Test (RBMT) assesses everyday memory by means of tasks which mimic daily challenges. The objective was to examine the validity of the Brazilian version of the RBMT to detect cognitive decline. METHODS 195 older adults were diagnosed as normal controls (NC) or with mild cognitive impairment (MCI) or Alzheimers disease (AD) by a multidisciplinary team, after participants completed clinical and neuropsychological protocols. RESULTS Cronbachs alpha was high for the total sample for the RBMT profile (PS) and screening scores (SS) (PS = 0.91, SS = 0.87) and for the AD group (PS = 0.84, SS = 0.85), and moderate for the MCI (PS = 0.62, SS = 0.55) and NC (PS = 0.62, SS = 0.60) groups. RBMT total scores, Appointment, Pictures, Immediate and Delayed Story, Immediate and Delayed Route, Delayed Message and Date contributed to differentiate NC from MCI. ROC curve analyses indicated high accuracy to differentiate NC from AD patients, and, moderate accuracy to differentiate NC from MCI. CONCLUSIONS The Brazilian version of the RBMT seems to be an appropriate instrument to identify memory decline in Brazilian older adults.

Combining functional scales and cognitive tests in screening for mild cognitive impairment at a university-based memory clinic in Brazil

OBJECTIVE To determine the diagnostic accuracy of the Mini-Mental State Examination combined to the Informant Questionnaire on Cognitive Decline in the Elderly for the identification of mild cognitive impairment. METHOD 191 elderly subjects were assessed with the Mini-Mental State Examination, and their informants were assessed with the Informant Questionnaire on Cognitive Decline in the Elderly. Subjects were divided into three groups according to their cognitive state (controls: n = 67, mild cognitive impairment: n = 65 and dementia: n = 59), which was ascertained by clinical and neuropsychological evaluation. The diagnostic accuracy of each test in the discrimination of diagnostic groups (mild cognitive impairment vs. controls, mild cognitive impairment vs. dementia and dementia vs. controls) was examined with the aid of ROC curves. We additionally verified if the combination of both tests would increase diagnostic accuracy for mild cognitive impairment and control identification. RESULTS The combination of the Mini-Mental State Examination and the Informant Questionnaire on Cognitive Decline in the Elderly scores did not increase the Mini-Mental State Examination diagnostic accuracy in the identification of patients with mild cognitive impairment. CONCLUSIONS The present data do not warrant the combination of the Mini-Mental State Examination and the Informant Questionnaire on Cognitive Decline in the Elderly as a sufficient diagnostic tool in the diagnostic screening for mild cognitive impairment.

Diagnosis of Mild Cognitive Impairment Revisited after One Year

Background/Aims: The diagnostic stability of mild cognitive impairment (MCI) on short-term follow-up is a key issue in the characterization of this clinical syndrome. We aim to determine the cognitive outcome after 1 year of follow-up in a cohort of older adults. Methods: Baseline clinical and neuropsychological assessments were carried out in older subjects recruited at a tertiary memory clinic. The subjects were reassessed after 1 year of follow-up with the same clinical and neuropsychological protocol. Results: A total of 115 older adults, including MCI (n = 54) and controls (n = 61), underwent baseline and follow-up evaluation. Ten subjects classified as MCI at baseline (23%) resumed normal cognitive function and 13 controls (21%) progressed to MCI upon follow-up (χ2 = 0.015, d.f. = 1, p = 0.90). The subjects diagnosed as having MCI on both assessments were older (p = 0.002) and had a worse global cognitive performance according to the Cambridge Cognitive Test (p = 0.014). Conclusion: The subjects who maintain the MCI status are older and have a worse baseline cognitive performance as well as multiple cognitive deficits.

Combining cognitive screening tests for the evaluation of mild cognitive impairment in the elderly

OBJECTIVE To determine the accuracy of the Mini-Mental State Examination combined with the Verbal Fluency Test and Clock Drawing Test for the identification of patients with mild cognitive impairment and Alzheimer’s disease (AD). METHOD These tests were used to evaluate cognitive function in 247 older adults. Subjects were divided into three groups according to their cognitive state: mild cognitive impairment (n=83), AD (n=81), cognitively unimpaired controls (n=83), based on clinical and neuropsychological data. The diagnostic accuracy of each test for discriminating between these diagnostic groups (mild cognitive impairment or AD vs. controls) was examined with the aid of Receiver Operating Characteristic (ROC) curves. Additionally, we evaluated the benefit of the combination of tests on diagnostic accuracy. RESULTS Although they were accurate enough for the identification of Alzheimer’s disease, neither test alone proved adequate for the correct separation of patients with mild cognitive impairment from healthy subjects. Combining these tests did not improve diagnostic accuracy, as compared to the Mini-Mental State Examination alone, in the identification of patients with mild cognitive impairment or Alzheimer’s disease. CONCLUSIONS The present data do not warrant the combined use of the Mini-Mental State Examination, the Verbal Fluency Test and the Clock Drawing Test as a sufficient diagnostic schedule in screening for mild cognitive impairment. The present data do not support the notion that the combination of test scores is better that the use of Mini-Mental State Examination scores alone in the screening for Alzheimer’s disease.