Valoración funcional en la demencia grave

Severe dementia is currently one of the main causes of dependence and is defined as cognitive impairment that interferes with the performance of basic activities of daily living. However, in clinical practice severe dementia is difficult to define.Assessment of the ability to perform activities of daily living is a key factor in patients with severe dementia, since functional impairment is a defining feature. Assessment allows an accurate prognosis to be made and a care plan to be established, as well as the effectiveness of the intervention to be evaluated, when necessary.Functional assessment in dementia is complex, since functional status is the expression of multiple interactions, especially in geriatric patients. Functional status is measured by functional scales. In severe dementia, these scales must evaluate basic activities of daily living in the different types of dementia with high sensitivity to changes and strong discriminatory capacity. They should also be culturally adapted and validated in the community and institutional settings. Consensus should be established on the use of these instruments to allow them to be standardized and their results to be compared.     

Episodic memory: new insights from the study of semantic dementia.

The study of patients with semantic dementia, the temporal variant of frontotemporal dementia, has provided new insights into the interaction between episodic and semantic memory, and the different roles played by various structures in the temporal lobe. Recent findings indicate that the syndrome of semantic dementia can inform us about the organisation of long-term memory and the relationship between semantic memory and other cognitive systems.     

Detection of Alzheimer's disease and dementia in the preclinical phase: population based cohort study

ObjectivesTo evaluate a simple three step procedure to identify people in the general population who are in the preclinical phase of Alzheimer''s disease and dementia.DesignThree year population based cohort study.SettingKungsholmen cohort, Stockholm, Sweden.Participants1435 people aged 75-95 years without dementia.AssessmentsSingle question asking about memory complaints, assessment by mini-mental state examination, and neuropsychological testing.ResultsNone of the three instruments was sufficiently predictive of Alzheimer''s disease and dementia when administered separately. After participants had been screened for memory complaints and global cognitive impairment, specific tests of word recall and verbal fluency had positive predictive values for dementia of 85-100% (95% confidence intervals range from 62% to 100%). However, only 18% of future dementia cases were identified in the preclinical phase by this three step procedure. Memory complaints were the most sensitive indicator of Alzheimer''s disease and dementia in the whole population, but only half the future dementia cases reported memory problems three years before diagnosis.ConclusionThis three step procedure, which simulates what might occur in clinical practice, has a high positive predictive value for dementia, although only a small number of future cases can be identified.

What is already known on this topic

Alzheimer''s disease is characterised by a preclinical phase, during which cognitive deficits are seen before diagnosisElderly people with subjective memory complaints and objective global cognitive impairment have a high risk of developing Alzheimer''s disease and dementia

What this study adds

This three step procedure (self report of memory complaints, test of global cognitive functioning, and then domain specific cognitive tests) has a positive predictivity of 85-100% for Alzheimer''s disease and dementia at three yearsHowever, only 18% of people in the preclinical phase can be identified using this procedureAbout half of the people in the preclinical phase of Alzheimer''s disease and dementia do not report problems with their memory three years before diagnosis     

Vasopressin treatment of cognitive dysfunction un progressive dementia

Progressive dementia patients demonstrate profound and obvious learning-memory impairments. To a large extent, these are determined by failures to access and use previously learned knowledge (semantic memory) to affect encoding and processing of ongoing events (episodic memory). There are other forms of memory failures in man that are likely to be determined by quite different psychobiological mechanisms, such as failures to retain or consolidate information in memory. One important way in which drug treatments may facilitate the learning-memory impairment in mildly demented patients is by making semantic memory structures more accessible. Patients treated with 1-desoamino-8-D-arginine vasopressin (DDAVP), a synthetic analog of the hypothalmic peptide arginine vasopressin, demonstrate cognitive enhancement by facilitating access to semantic memory structures that are part of long-term memory.     

Episodic memory: insights from semantic dementia

Semantic dementia, also known as the temporal lobe variant of fronto-temporal dementia, results in a progressive yet relatively pure loss of semantic knowledge about words, objects and people, and is associated with asymmetric, focal atrophy of the antero-lateral temporal lobes. Semantic dementia provides a unique opportunity to study the organization of long-term memory particularly since initial observations suggested sparing of episodic memory. Recent studies reveal, however, a more complex but theoretically revealing pattern. On tests of autobiographical memory, patients with semantic dementia show a 'reverse step function' with sparing of recall of events from the most recent 2 to 5 years but impairment on more distant life periods. Anterograde recognition memory for visual materials is extremely well preserved, except in the most deteriorated cases, although performance is heavily reliant upon perceptual information about the studied stimuli, particularly for items that are no longer known by the subjects. On tests of verbal anterograde memory such as word learning, performance is typically poor even for words which are 'known' to the patients. A source discrimination experiment, designed to evaluate familiarity and recollection-based anterograde memory processes, found that patients with semantic dementia showed good item detection, although recollection of source was sometimes impaired. Semantic knowledge about studied items and measures of item detection and source discrimination were largely independent. The implications of these findings for models of long-term memory are discussed. The results support the concept that episodic memory, or at least the recall of temporally specific autobiographical experiences, draws upon a number of separable memory processes, some of which can function independently of semantic knowledge.     

Associations between White Matter Microstructure and Cognitive Performance in Old and Very Old Age

Increasing age is associated with deficits in a wide range of cognitive domains as well as with structural brain changes. Recent studies using diffusion tensor imaging (DTI) have shown that microstructural integrity of white matter is associated with cognitive performance in elderly persons, especially on tests that rely on perceptual speed. We used structural equation modeling to investigate associations between white matter microstructure and cognitive functions in a population-based sample of elderly persons (age ≥ 60 years), free of dementia, stroke, and neurological disorders (n = 253). Participants underwent a magnetic resonance imaging scan, from which mean fractional anisotropy (FA) and mean diffusivity (MD) of seven white matter tracts were quantified. Cognitive functioning was analyzed according to performance in five task domains (perceptual speed, episodic memory, semantic memory, letter fluency, and category fluency). After controlling for age, FA and MD were exclusively related to perceptual speed. When further stratifying the sample into two age groups, the associations were reliable in the old-old (≥78 years) only. This relationship between white matter microstructure and perceptual speed remained significant after excluding persons in a preclinical dementia phase. The observed pattern of results suggests that microstructural white matter integrity may be especially important to perceptual speed among very old adults.     

Neurocognitive function in adults with growth hormone deficiency

The clinical condition of growth hormone deficiency (GHD) as a consequence of pituitary or hypothalamic disease has been associated with reduced cognitive performance. In several studies, neuropsychological assessment has been performed in adults with GHD both before and after growth hormone (GH) replacement therapy. Interpretation of the available data is complicated by the variation in patient selection as well as the neuropsychological tests used in such studies. Most of the available studies indicate that GHD can lead to small, but clinically relevant changes in memory, processing speed and attention. Some of these changes may be reversed by GH replacement, although the number of reliable intervention studies is limited. In addition to the possible clinical relevance of neuropsychological improvement following GH replacement in patients with GHD, the observed findings may be of interest for studies in neurocognitive performance in other conditions associated with changes in the activity of the somatotrophic axis, and in the understanding of underlying pathophysiological mechanisms.     

Patterns of cognitive performance in healthy ageing in Northern Portugal: a cross-sectional analysis

Background

The Minho Integrative Neuroscience Database (MIND)-Ageing project aims to identify predictors of healthy cognitive ageing, including socio-demographic factors. In this exploratory analysis we sought to establish baseline cohorts for longitudinal assessment of age-related changes in cognition.

Methods

The population sample (472 individuals) was strictly a convenient one, but similar to the Portuguese population in the age profile. Participants older than 55 years of age were included if they did not present defined disabling pathologies or dementia. A standardized clinical interview was conducted to assess medical history and a battery of neuropsychological tests was administered to characterize global cognition (Mini Mental State Examination), memory and executive functions (Selective Reminding Test; Stroop Color and Word Test; and Block Design subtest of the Wechsler Adult Intelligence Scale). Cross-sectional analysis of the neuropsychological performance with individual characteristics such as age, gender, educational level and setting (retirement home, senior university, day care center or community), allowed the establishment of baseline clusters for subsequent longitudinal studies.

Results

Based on different socio-demographic characteristics, four main clusters that group distinctive patterns of cognitive performance were identified. The type of institution where the elders were sampled from, together with the level of formal education, were the major hierarchal factors for individual distribution in the four clusters. Of notice, education seems to delay the cognitive decline that is associated with age in all clusters.

Conclusions

Social-inclusion/engagement and education seem to have a protective effect on mental ageing, although this effect may not be effective in the eldest elders.     

Changes in life-quality, a possible symptom of dementia development

Dementia is a chronic and irreversible brain impairment characterised by significant cognitive deficits. Severe symptoms of the aforesaid disease interfere with normal life functions and daily activities. Dementia usually develops with advancing age, i.e. after the age of 85, and when it develops in people younger than age 65, it is referred to as early onset dementia. This paper presents a 53-year-old male patient. Provisional diagnosis was established while further diagnostic workup included psycho-diagnostic assessment, neurological exam, and brain CT Such workup confirmed the development of dementia, i.e. early-onset Alzheimer's disease accompanied by depressed mood with impaired vision.     

The diagnostic value of drawing a clock in geriatrics

In this study the Clock Drawing Test (CDT) is used in a geriatric department to search for dementia in a population with somatic disorders (N=236). The demented group (N=113) has significant lower scores on every item and on the total score of the scoring method, compared to the non-demented group (N=123). A factor analysis of the scoring method shows that the fourteen items can be grouped into the three groups "contour", "digits", and "hands". A logistic regression shows that "hands" is the most discriminating, although this effect is moderate (sensitivity 59.3%, specificity 75.6%). Considering however that the CDT, compared to other screening tasks, appeals to an unique combination of cognitive functions, including visual semantic memory, working memory, visuospatial skills, attention and executive functions, it can be concluded that this test can contribute to the diagnoses of dementia, besides the traditionally used instruments.     

Abnormal semantic processing in females with fragile X‐associated tremor/ataxia syndrome

Fragile X‐associated tremor/ataxia syndrome (FXTAS), a neurodegenerative disorder, affects fragile X (FMR1) gene premutation carriers in late life. Studies have shown cognitive impairments in FXTAS including executive dysfunction, working memory and visuospatial deficits. However, less is known about cognition in females with FXTAS. Thus, we examined semantic processing and verbal memory in female FXTAS patients with event‐related potentials (ERPs) and neuropsychological testing. Sixty‐one females (34 FXTAS, M_age = 62.7; 27 controls, M_age = 60.4) were studied with 32‐channel ERPs during a category judgment task in which semantically congruous (50%) and incongruous items were repeated approximately 10–140 seconds later. N400 and P600 amplitude data were submitted to analysis of covariance. Neuropsychological testing demonstrated lower performance in verbal learning and executive function in females with FXTAS. Event‐related potential analyses showed a significant reduction of the N400 congruity effect (incongruous ? congruous) in the FXTAS group. The N400 congruity effect reduction in females with FXTAS was mainly due to increased N400 amplitude to congruous new words. No significant abnormalities of the N400 repetition effect or the P600 repetition effect were found, indicating preserved implicit memory and verbal memory, respectively, in females with FXTAS. The decreased N400 congruity effect suggests abnormal semantic expectancy and/or semantic network disorganization in female FXTAS patients. The enhanced N400 amplitude to congruous new words may reflect decreased cognitive flexibility among FXTAS women, making access to less typical category exemplar words more difficult .     

Age-Related Changes of Adaptive and Neuropsychological Features in Persons with Down Syndrome

Down Syndrome (DS) is characterised by premature aging and an accelerated decline of cognitive functions in the vast majority of cases. As the life expectancy of DS persons is rapidly increasing, this decline is becoming a dramatic health problem. The aim of this study was to thoroughly evaluate a group of 67 non-demented persons with DS of different ages (11 to 66 years), from a neuropsychological, neuropsychiatric and psychomotor point of view in order to evaluate in a cross-sectional study the age-related adaptive and neuropsychological features, and to possibly identify early signs predictive of cognitive decline. The main finding of this study is that both neuropsychological functions and adaptive skills are lower in adult DS persons over 40 years old, compared to younger ones. In particular, language and short memory skills, frontal lobe functions, visuo-spatial abilities and adaptive behaviour appear to be the more affected domains. A growing deficit in verbal comprehension, along with social isolation, loss of interest and greater fatigue in daily tasks, are the main features found in older, non demented DS persons evaluated in our study. It is proposed that these signs can be alarm bells for incipient dementia, and that neuro-cognitive rehabilitation and psycho-pharmacological interventions must start as soon as the fourth decade (or even earlier) in DS persons, i.e. at an age where interventions can have the greatest efficacy.     

Cognitive dysfunction in rapid eye movement sleep behavior disorder

Cognitive impairment is a frequent feature of rapid eye movement sleep behavior disorder (RBD). The cognitive profile of RBD patients is heterogeneous, with impairments in attention, executive functions, episodic memory, and visuospatial abilities. Moreover, over 50% of RBD patients meet the diagnostic criteria for mild cognitive impairment (MCI). Although a comprehensive neuropsychological assessment remains the most sensitive way to detect MCI, three cognitive screening tests have been validated in RBD. The Montreal Cognitive Assessment was found to be the most appropriate screening test for detecting MCI in RBD. In addition RBD in Parkinson’s disease may be a risk factor for MCI and dementia.

     

The Montreal Cognitive Assessment (MoCA) - A Sensitive Screening Instrument for Detecting Cognitive Impairment in Chronic Hemodialysis Patients

Background

Chronic kidney disease (CKD) patients undergoing hemodialysis (HD) therapy have an increased risk of developing cognitive impairment and dementia, which are known relevant factors in disease prognosis and therapeutic success, but still lack adequate screening in clinical routine. We evaluated the Montreal Cognitive Assessment (MoCA) for suitability in assessing cognitive performance in HD patients in comparison to the commonly used Mini-Mental State Examination (MMSE) and a detailed neuropsychological test battery, used as gold standard.

Methods

43 HD patients and 42 healthy controls with an average age of 58 years, were assessed with the MoCA, the MMSE and a detailed neuropsychological test battery, covering the domains of memory, attention, language, visuospatial and executive functions. Composite scores were created for comparison of cognitive domains and test results were analyzed using Spearman''s correlation and linear regression. Cognitive dysfunction was defined using z-score values and predictive values were calculated. Sensitivity and specificity of the MoCA were determined using receiver operating characteristic (ROC) analysis.

Results

HD patients performed worse in all cognitive domains, especially in memory recall and executive functions. The MoCA correlated well with the detailed test battery and identified patients with cognitive impairment with a sensitivity of 76.7% and specificity of 78.6% for a cut-off value of ≤24 out of 30 points. In the detailed assessment executive functions accounted significantly for performance in the MoCA. The MMSE only discriminated weakly between groups.

Conclusions

The MoCA represents a suitable cognitive screening tool for hemodialysis patients, demonstrating good sensitivity and specificity levels, and covering executive functions, which appear to play an important role in cognitive performance of HD patients.     

Cognitive function in growth hormone deficiency and growth hormone replacement

There is converging evidence from neuropsychological studies that growth hormone (GH) is associated with cognitive function. The aim of the current study was to review the existing neuropsychological literature for studies in which cognitive assessment had been conducted in patients with GH deficiency (GHD), and where change in cognitive function had been assessed following treatment with GH. Studies that have investigated relationships between GH and cognitive function and those that have developed methodological and statistical approaches that could be useful in future GH studies were identified. In this review, GH levels were found to be associated with cognitive function. Untreated individuals with GHD showed reliable impairment in memory and attentional functions when compared with matched controls. Appropriately designed prospective studies also indicated that cognitive function improved with GH treatment. It was concluded that individuals with GHD do show cognitive impairment and that this is ameliorated to some extent by GH treatment. It is now important to establish the clinical importance of these findings, and further work is required to understand better the nature, magnitude and meaning of GH-related cognitive impairments and improvements.     

Subjective Memory Evaluation before and after Temporal Lobe Epilepsy Surgery

Subjective memory (SM), a self-evaluation of memory, in contrast to objective memory (OM) measured by neuropsychological testing, is less well studied in patients with epilepsy. We assessed SM before and after temporal lobectomy. The Frequency of Forgetting 10 scale (FOF-10), developed to evaluate SM in dementia, was given before and one year after temporal lobectomy. Reliability and validity for use in epilepsy were first assessed. Measures of depression (CES-D) and neuroticism (PANAS) were done before and after surgery as well as complete neuropsychological assessment of OM. Correlation analysis between FOF-10 results and all the other variables was implemented. In 48 patients the FOF-10 was reliable and valid showing high internal consistency in all items (Cronbach''s alpha >0.82) and high reproducibility (p<0.01). The FOF-10 also correlated with the memory assessment clinics self rating scale (MAC-S) (p<0.01). FOF-10 scores improved or were unchanged postoperatively in 28 patients (58%) and worsened in 20 (42%). The FOF-10 did not significantly correlate with memory scores from neuropsychological testing but did correlate with perceived word finding difficulty (p<0.001) and postoperative depression (p<0.05). A reduction in number of antiepileptic drugs (AEDs) after surgery distinguished those with improved postoperative SM. No correlation was found between SM and neuroticism, side of surgery or number of seizures. The FOF-10 is a brief and reliable measure of subjective memory in patients with epilepsy. Perceived memory impairment reflects more emotional state, language problems and quantity of AEDs than actual defects in memory function. These results would potentially be useful in presurgical counselling and management of memory issues after temporal lobe surgery.     

Neural Substrates of Cognitive Subtypes in Parkinson's Disease: A 3-Year Longitudinal Study

Background

The neuropsychological features and neuropathological progression patterns associated with rapidly evolving cognitive decline or dementia in Parkinson''s disease (PD) remain to be elucidated.

Methods

Fifty-three PD patients without dementia were recruited to participate in a 3-year longitudinal cohort study. The patients were grouped according to the Clinical Dementia Rating (CDR). Group-wise comparisons were made with regard to demographic characteristics, motor symptoms, neuropsychological performances and 18F-fluorodeoxyglucose positron emission tomography.

Results

Patients who had memory-plus cognitive impairment (patients whose CDR was 0 at baseline and 0.5 in memory and other domains at follow-up, and those whose baseline CDR was 0.5 in memory and other domains) exhibited higher age at onset, visuoperceptual impairment, non-tremor-dominant motor disturbance, rapid symptomatic progression and posterior neocortical hypometabolism. In patients who were cognitively unimpaired and those who had memory-dominant cognitive impairment (patients whose CDR was 0 at baseline and 0.5 only in memory domain at follow-up, and those whose baseline CDR was 0.5 only in memory domain), the posterior neocortex was relatively unaffected until a later stage of the disease.

Conclusions

These results suggest that visuoperceptual impairment and the early involvement of the posterior neocortex may be risk factors for rapid symptomatic progression and dementia in PD.     

Study protocol: EXERcise and Cognition in Sedentary adults with Early-ONset dementia (EXERCISE-ON)

ABSTRACT: BACKGROUND: Although the development of early-onset dementia is a radical and invalidating experience for both patient and family there are hardly any non-pharmacological studies that focus on this group of patients. One type of a non-pharmacological intervention that appears to have a beneficial effect on cognition in older persons without dementia and older persons at risk for dementia is exercise. In view of their younger age early-onset dementia patients may be well able to participate in an exercise program. The main aim of the EXERCISE-ON study is to assess whether exercise slows down the progressive course of the symptoms of dementia. METHODS: One hundred and fifty patients with early-onset dementia are recruited. After completion of the baseline measurements, participants living within a 50 kilometre radius to one of the rehabilitation centres are randomly assigned to either an aerobic exercise program in a rehabilitation centre or a flexibility and relaxation program in a rehabilitation centre. Both programs are applied three times a week during 3 months. Participants living outside the 50 kilometre radius are included in a feasibility study where participants join in a daily physical activity program set at home making use of pedometers. Measurements take place at baseline (entry of the study), after three months (end of the exercise program) and after six months (follow-up). Primary outcomes are cognitive functioning; psychomotor speed and executive functioning; (instrumental) activities of daily living, and quality of life. Secondary outcomes include physical, neuropsychological, and rest-activity rhythm measures. DISCUSSION: The EXERCISE-ON study is the first study to offer exercise programs to patients with early-onset dementia. We expect this study to supply evidence regarding the effects of exercise on the symptoms of early-onset dementia, influencing quality of life.Trial registrationThe present study is registered within The Netherlands National Trial Register (ref: NTR2124).     

Demographic and cognitive predictors of cued odor identification: evidence from a population-based study

This study investigated demographic and cognitive correlates of cued odor identification in a population-based sample from the Betula project: 1906 healthy adults varying in age from 45 to 90 years were assessed in a number of tasks tapping various cognitive domains, including cognitive speed, semantic memory and executive functioning. The results revealed a gradual and linear deterioration in cued odor identification across the adult life span. Overall, females identified more odors than men, although men and women performed at the same level in the oldest age cohort (85-90 years). Hierarchical regression analyses revealed that age, sex, education, cognitive speed and vocabulary were reliable correlates of performance in the odor identification task. In addition, age-related deficits in the included demographic and cognitive variables could not fully account for the observed age-related impairment in identification, suggesting that additional factors are underlying the observed deterioration. Likely candidates here are sensory abilities such as olfactory detection and discrimination.     

Implications of neuropsychological evidence for theories of normal memory

The relation between neuropsychology and the study of normal cognitive function is discussed in the context of recent research on human memory. It is suggested that neuropsychological evidence has clear implications for the fractionation of human memory into subsystems. The distinction between long-term and short-term memory, between semantic and episodic memory, and the further fractionation of short-term or working memory all offer examples of concepts that have been successfully applied within the neuropsychological domain, and where the neuropsychological evidence has led to a modification and development of the original concept. Attempts to offer a cognitive interpretation of the amnesic syndrome are discussed. While none of these is entirely satisfactory, such work has led to a potentially important distinction between autobiographical memory or recollection, which is defective in amnesic patients, and a more perceptual or procedural learning process, which appears to be intact in such patients. Recent research on normal subjects is beginning to reveal a similar distinction. It is concluded that the relation between neuropsychology and the study of normal cognitive function continues to be an extremely fruitful one.