Early Intervention Is Key to Successful Management of Alzheimer Disease

Digital Cognitive Biomarker for Mild Cognitive Impairments and Dementia: A Systematic Review

The dementia population is increasing as the world's population is growing older. The current systematic review aims to identify digital cognitive biomarkers from computerized tests for detecting dementia and its risk state of mild cognitive impairment (MCI), and to evaluate the diagnostic performance of digital cognitive biomarkers. A literature search was performed in three databases, and supplemented by a Google search for names of previously identified computerized tests. Computerized tests were categorized into five types, including memory tests, test batteries, other single/multiple cognitive tests, handwriting/drawing tests, and daily living tasks and serious games. Results showed that 78 studies were eligible. Around 90% of the included studies were rated as high quality based on the Newcastle-Ottawa Scale (NOS). Most of the digital cognitive biomarkers achieved comparable or even better diagnostic performance than traditional paper-and-pencil tests. Moderate to large group differences were consistently observed in cognitive outcomes related to memory and executive functions, as well as some novel outcomes measured by handwriting/drawing tests, daily living tasks, and serious games. These outcomes have the potential to be sensitive digital cognitive biomarkers for MCI and dementia. Therefore, digital cognitive biomarkers can be a sensitive and promising clinical tool for detecting MCI and dementia.

Can discourse processing performance serve as an early marker of Alzheimer’s disease and mild cognitive impairment? A systematic review of text comprehension

A number of linguistic and cognitive deficits have been reported during the course of Alzheimer’s disease (AD) and its preceding stage of mild cognitive impairment (MCI), with some deficits appearing years before onset of clinical symptoms. It continues to be a critical task to identify tools that may serve as an early marker of pathology that are also reliably able to distinguish AD from normal ageing. Given the limited success of classic psychometric cognitive testing, a novel approach in assessment is warranted. A potentially sensitive assessment paradigm is discourse processing. The aim of this review was to synthesize original research studies investigating comprehension of discourse in AD and MCI, and to evaluate the potential of this paradigm as a promising avenue for further research. A literature search targeting studies with AD or MCI groups over 60 years of age was conducted in PubMed, Web of Science, and PsycINFO databases. Eight articles with good quality were included in the review. Six measures of discourse comprehension—naming latency, summary, lesson, main idea, proportion of inferential clauses, true/false questions—were identified. All eight studies reported significant deficits in discourse comprehension in AD and MCI groups on five of the six measures, when compared to cognitively healthy older adults. Mixed results were observed for associations with commonly used cognitive measures. Given the consistent findings for discourse comprehension measures across all studies, we strongly recommend further research on its early predictive potential, and discuss different avenues for research.

Evaluating Infectious, Neoplastic, Immunological, and Degenerative Diseases of the Central Nervous System with Cerebrospinal Fluid-Based Next-Generation Sequencing

Cerebrospinal fluid (CSF) is a clear and paucicellular fluid that circulates within the ventricular system and the subarachnoid space of the central nervous system (CNS), and diverse CNS disorders can impact its composition, volume, and flow. As conventional CSF testing suffers from suboptimal sensitivity, this review aimed to evaluate the role of next-generation sequencing (NGS) in the work-up of infectious, neoplastic, neuroimmunological, and neurodegenerative CNS diseases. Metagenomic NGS showed improved sensitivity—compared to traditional methods—to detect bacterial, viral, parasitic, and fungal infections, while the overall performance was maximized in some studies when all diagnostic modalities were used. In patients with primary CNS cancer, NGS findings in the CSF were largely concordant with the molecular signatures derived from tissue-based molecular analysis; of interest, additional mutations were identified in the CSF in some glioma studies, reflecting intratumoral heterogeneity. In patients with metastasis to the CNS, NGS facilitated diagnosis, prognosis, therapeutic management, and monitoring, exhibiting higher sensitivity than neuroimaging, cytology, and plasma-based molecular analysis. Although evidence is still rudimentary, NGS could enhance the diagnosis and pathogenetic understanding of multiple sclerosis in addition to Alzheimer and Parkinson disease. To conclude, NGS has shown potential to aid the research, facilitate the diagnostic approach, and improve the management outcomes of all the aforementioned CNS diseases. However, to establish its role in clinical practice, the clinical validity and utility of each NGS protocol should be determined. Lastly, as most evidence has been derived from small and retrospective studies, results from randomized control trials could be of significant value.

Intention to Be Screened for Alzheimer's Disease in Nondemented Older Adults: Integrated Behavioral Model and Self-Efficacy as Mediation Effect

The study explored factors associated with intention to be screened for Alzheimer's disease (AD). The study also examined whether self-efficacy mediates the relationship between knowledge about screening and the intention to be screened for AD. A population-based, random-digit dialing survey was performed and 1,043 responses were collected from a sample of nondemented persons (50 years or older) living in urban, suburban, and rural areas in a Midwestern state. The findings showed that participants who were younger and who had higher levels of (a) perceived benefits and barriers, (b) social support, and (c) self-efficacy reported higher levels of intention to be screened for AD. Older adults with positive life orientation reported greater intention to be screened for AD, whereas depressed participants were more likely to report a plan to be screened for AD. Self-efficacy mediated the relationship between knowledge about screening and intention to be screened. Older adults were more likely to report intention to be screened when they had positive attitudes about the screen and believed that they could receive the screen. The intention to be screened for AD could serve public awareness by defining effective ways to assist older adults to seek a cognitive screen.

[Mild cognitive impairment: what's next?]

The concept of mild cognitive impairment is one of the promising directions for studying the predementia stages of different diseases. The feasibility of studying this phenomenon is due not only to a high risk of dementia, but also the potential reversibility of cognitive decline in old age. Long-term follow-up of patients shows different trajectories of cognitive decline in aging. The study of risk factors for the progression of moderate cognitive impairment provided an opportunity to highlight new horizons of prevention of dementia of various etiologies. Despite the insufficient effectiveness of drug therapy in patients with moderate cognitive impairment, exploring the opportunities for possible treatment of their subtypes seems promising from the point of view of improving clinical symptoms and a possible reduction in the rate of disease progression.

Utilization of Magnetic Resonance Imaging by Comorbidity of Patients with Dementia

Dementia produces major clinical and social problems that have catastrophic consequences for patients and their families. Dementia also complicates clinical care for other co-existing medical conditions. Magnetic Resonance Imaging (MRI) utilization is increasingly used for diagnostic purposes, such as early diagnosis of dementia and special examination of dementia. This study analyzed the utilization status and factors affecting use of MRI examination of patients with dementia using the Charlson Comorbidity Index (CCI). We used data from the Korean National Hospital Discharge In-depth Injury Survey (KNHDS) for three years, from 2013 to 2015, investigated by Korea Centers for Disease Control and Prevention (KCDC). The subjects of the study were 643 patients whose primary diagnosis code according to the International Classification of Disease (ICD) is F00–F03 (dementia in Alzheimer’s disease, vascular dementia, unspecified dementia, etc.). As independent variables, we used sex, age, type of insurance, the admission route, length of stay, result of treatment, number of hospital beds, and the hospital’s location. In this study, the independent variables affecting MRI examination of dementia patients were length of stay, hospital location, and CCI. The ratio of MRI examination of patients with dementia in which the CCI was 1, was significantly higher by 1.757 times than in cases where the CCI was 0. Hence, it can be used to provide basic data for formulating health care policy for dementia patients by studying their overall situation.

Subjective memory complaints are associated with brain activation supporting successful memory encoding

Subjective memory complaints, the perceived decline in cognitive abilities in the absence of clinical deficits, may precede Alzheimer's disease. Individuals with subjective memory complaints show differential brain activation during memory encoding; however, whether such differences contribute to successful memory formation remains unclear. Here, we investigated how subsequent memory effects, activation which is greater for hits than misses during an encoding task, differed between healthy older adults aged 50 to 85 years with (n = 23) and without (n = 41) memory complaints. Older adults with memory complaints, compared to those without, showed lower subsequent memory effects in the occipital lobe, superior parietal lobe, and posterior cingulate cortex. In addition, older adults with more memory complaints showed a more negative subsequent memory effects in areas of the default mode network, including the posterior cingulate cortex, precuneus, and ventromedial prefrontal cortex. Our findings suggest that for successful memory formation, older adults with subjective memory complaints rely on distinct neural mechanisms which may reflect an overall decreased task-directed attention.

Disease Progression in Mild Dementia due to Alzheimer Disease in an 18-Month Observational Study (GERAS): The Impact on Costs and Caregiver Outcomes

Background/Aims

We assessed whether cognitive and functional decline in community-dwelling patients with mild Alzheimer disease (AD) dementia were associated with increased societal costs and caregiver burden and time outcomes.

Methods

Cognitive decline was defined as a ≥3-point reduction in the Mini-Mental State Examination and functional decline as a decrease in the ability to perform one or more basic items of the Alzheimer's Disease Cooperative Study Activities of Daily Living Inventory (ADCS-ADL) or ≥20% of instrumental ADL items. Total societal costs were estimated from resource use and caregiver hours using 2010 costs. Caregiver burden was assessed using the Zarit Burden Interview (ZBI); caregiver supervision and total hours were collected.

Results

Of 566 patients with mild AD enrolled in the GERAS study, 494 were suitable for the current analysis. Mean monthly total societal costs were greater for patients showing functional (+61%) or cognitive decline (+27%) compared with those without decline. In relation to a typical mean monthly cost of approximately EUR 1,400 at baseline, this translated into increases over 18 months to EUR 2,254 and 1,778 for patients with functional and cognitive decline, respectively. The number of patients requiring supervision doubled among patients showing functional or cognitive decline compared with those not showing decline, while caregiver total time increased by 70 and 33%, respectively and ZBI total score by 5.3 and 3.4 points, respectively.

Conclusion

Cognitive and, more notably, functional decline were associated with increases in costs and caregiver outcomes in patients with mild AD dementia.

Flexible vs Rigid Epitope Conformations for Diagnostic- and Vaccine-Oriented Applications: Novel Insights from the Burkholderia pseudomallei BPSL2765 Pal3 Epitope

Peptides seldom retain stable conformations if separated from their native protein structure. In an immunological context, this potentially affects the development of selective peptide-based bioprobes and, from a vaccine perspective, poses inherent limits in the elicitation of cross-reactive antibodies by candidate epitopes. Here, a 1,4-disubstituted-1,2,3-triazole-mediated stapling strategy was used to stabilize the native α-helical fold of the Pal3 peptidic epitope from the protein antigen PalBp (BPSL2765) from Burkholderia pseudomallei, the etiological agent of melioidosis. Whereas Pal3 shows no propensity to fold outside its native protein context, the engineered peptide (Pal3H) forms a stable α-helix, as assessed by MD, NMR, and CD structural analyses. Importantly, Pal3H shows an enhanced ability to discriminate between melioidosis patient subclasses in immune sera reactivity tests, demonstrating the potential of the stapled peptide for diagnostic purposes. With regard to antibody elicitation and related bactericidal activities, the linear peptide is shown to elicit a higher response. On these bases, we critically discuss the implications of epitope structure engineering for diagnostic- and vaccine-oriented applications.

Neuropsychological test performance and cognitive reserve in healthy aging and the Alzheimer's disease spectrum: a theoretically driven factor analysis

Accurate measurement of cognitive function is critical for understanding the disease course of Alzheimer's disease (AD). Detecting cognitive change over time can be confounded by level of premorbid intellectual function or cognitive reserve and lead to under- or over-diagnosis of cognitive impairment and AD. Statistical models of cognitive performance that include cognitive reserve can improve sensitivity to change and clinical efficacy. We used confirmatory factor analysis to test a four-factor model composed of memory/language, processing speed/executive function, attention, and cognitive reserve factors in a group of cognitively healthy older adults and a group of participants along the spectrum of amnestic mild cognitive impairment to AD (aMCI-AD). The model showed excellent fit for the control group (χ(2) = 100; df = 78; CFI = .962; RMSEA = .049) and adequate fit for the aMCI-AD group (χ(2) = 1750; df = 78; CFI = .932; RMSEA = .085). Although strict invariance criteria were not met, invariance testing to determine if factor structures are similar across groups yielded acceptable absolute model fits and provide evidence in support of configural, metric, and scalar invariance. These results provide further support for the construct validity of cognitive reserve in healthy and memory impaired older adults.

Temporal stability of receptiveness to clinical research on Alzheimer disease

Research advance directives are a proposed mechanism for ensuring that decisions with regard to research participation adhere to preferences voiced by persons with Alzheimer disease (AD) before losing decisional capacity. Although this approach rests on the assumption that preferences with regard to research participation are consistent over time, little is known about the stability of such preferences. The purpose of this study was to evaluate the temporal stability of older adults' receptiveness to participation in clinical trials, neuroimaging studies, and psychosocial investigations on AD. One hundred and four participants in the University of Pittsburgh Alzheimer Disease Research Center were annually surveyed with regard to their willingness to be contacted with regard to clinical drug trials, neuroimaging studies, and psychosocial research for which they might be eligible. Receptiveness to contact with regard to AD research was compared at 2 time points, 1 year apart. At baseline, most respondents were willing to be contacted with regard to their eligibility for drug trials, imaging studies, and psychosocial research. Thirty-seven percent of respondents voiced a different set of preferences at year 2 as compared with year 1. Differences included both increased and decreased willingness to be contacted. Neither stability of preferences nor direction of change (more vs. less willing) varied by diagnostic group. Bivariate analyses revealed that participation in at least 1 ancillary research study was associated with an overall increase in willingness to be contacted. We conclude that a significant proportion of research-friendly individuals voice different sets of preferences with regard to the possibility of research participation when queried at different points in time. Amenability to participating in clinical research on AD is a relatively dynamic personal attribute that may be influenced by personal experience with research participation. This finding has relevance for the policy debate around research advance directives, an approach which assumes that preferences with regard to research participation are consistent over time.

Combination of p53(ser15) and p21/p21(thr145) in peripheral blood lymphocytes as potential Alzheimer's disease biomarkers

Alzheimer's disease (AD) is still difficult to be precisely diagnosed in its early stage to date. Establishing of reliable and manageable disease-specific biological markers is required to improve diagnostic accuracy. Based on the hypothesis of cell cycle regulatory failure at the early stage of AD, we tested whether cell cycle regulating proteins p53, p21 and their phosphorylated forms p53(ser15), p21(thr145) were changed in AD patients and whether these proteins could be used as diagnostic biomarkers. Western bolt, Enzyme-linked immunosorbent assay (ELISA), immunofluorescent staining and flow cytometry (FCM) analysis were employed to analyze levels of these proteins in peripheral blood lymphocytes (PBLs) from 95 controls, 94 AD, 12 Parkinson's disease (PD) and 15 vascular dementia (VaD) patients. Compared with controls, p53(ser15) and p21(thr145) levels were significantly increased and p21 level was significantly decreased in PBLs of AD patients but not in PD or VaD, while p53 was increased in both AD and VaD patients. The receiver operating characteristic (ROC) curve analysis showed that the specificity and sensitivity were 76% and 84% for p53, 88% and 82% for p53(ser15), 80% and 75% for p21 and 84% and 68% for p21(thr145) in identifying AD patients. The relatively high diagnostic accuracy support these proteins, especially p53(ser15) and p21 in PBLs may become potential biomarkers for diagnosis of AD.

Videoconference diagnosis and management of Choctaw Indian dementia patients

BACKGROUND

This study reports a 5-year experience using videoconference (VC) technology in diagnosing and treating adult members of the Choctaw Nation with symptoms or complaints of cognitive impairment.

METHODS

Patients were given the option of a VC session or a face-to-face evaluation in the clinic. Before their VC session, patients underwent neuropsychological testing, Clinical Dementia Rating, Geriatric Depression Scale and Neuropsychiatric Inventory, brain computed tomography, and routine blood tests. Physical observations made by VC included eyesight, hearing, facial expression, gait and station, coordination, tremor, rapid alternating movements, psychomotor activity, and motor tests of executive function. Cogwheeling and rigidity were tested by our on-site nurse, who also obtained vital signs as indicated.

RESULTS

Between January 2005 and March 2010, there were 47 clinics, 171 visits, and 85 unique patients. There were 52 new evaluations and 119 follow-up visits. The number of visits ranged from one to eight and the length of follow-up from 1 month to 4.5 years. The no-show rate for all VC sessions in 2009 was 3%, and only two subjects in 5 years refused further VC visits.

CONCLUSION

Once cultural barriers are dealt with, VC-based diagnosis and treatment of adults with cognitive disorders who live in remote areas is feasible and well accepted by patients and families.

A Review of Diagnostic Process and Postdiagnostic Support for People With Dementia in Rural Areas

Purpose: Early diagnosis of dementia allows the affected individuals to make plans, and helps services to identify and act on need. Previous work has suggested that obtaining an early diagnosis in rural areas can be difficult. This paper discusses diagnosis and postdiagnostic support for people with dementia, with a focus on service delivery in rural areas. Methods: A review of published English language literature 1999 to 2011 identified in Medline, PsycINFO, PubMed, Cochrane Library, and ScienceDirect. Results: Primary care services play a key role in accessing services in many health care systems. The role of primary care staff, and in particular general practitioners, is greatest in rural communities where specialist service access is often reduced. Despite this, rural staff often report limited training on supporting people with dementia. Postdiagnostic services can be more difficult to access in rural areas, and informal caregivers in rural areas can be more reluctant to seek such services. Transport difficulties and distance from specialist services can act as a barrier to service use. Memory services have been offered in both rural and urban areas. Conclusions: Addressing stigma, supporting staff, and signposting access are important in all areas, but seem to be particularly important in rural areas. Training and support for general staff in rural areas can be improved. Memory services provide one way of delivering services in rural areas. Service planners should take negative perceptions of dementia, barriers to access, and training of generalist service providers into account when designing dementia services in rural areas.

Endothelin receptor antagonists: potential in Alzheimer's disease

Alzheimer's disease (AD) is believed to be initiated by the accumulation of neurotoxic forms of Aβ peptide within the brain. AD patients show reduction of cerebral blood flow (CBF), the extent of the reduction correlating with the impairment of cognition. There is evidence that cerebral hypoperfusion precedes and may even trigger the onset of dementia in AD. Cerebral hypoperfusion impairs neuronal function, reduces the clearance of Aβ peptide and other toxic metabolites from the brain, and upregulates Aβ production. Studies in animal models of AD have shown the reduction in CBF to be more than would be expected for the reduction in neuronal metabolic activity. Aβ may contribute to the reduction in CBF in AD, as both Aβ₁₋₄₀ and Aβ₁₋₄₂ induce cerebrovascular dysfunction. Aβ₁₋₄₀ acts directly on cerebral arteries to cause cerebral smooth muscle cell contraction. Aβ₁₋₄₂ causes increased neuronal production and release of endothelin-1 (ET-1), a potent vasoconstrictor, and upregulation of endothelin-converting enzyme-2 (ECE-2), the enzyme which cleaves ET-1 from its inactive precursor. ET-1 and ECE-2 are also elevated in AD, making it likely that upregulation of the ECE-2-ET-1 axis by Aβ₁₋₄₂ contributes to the chronic reduction of CBF in AD. At present, only a few symptomatic treatment options exist for AD. The involvement of ET-1 in the pathogenesis of endothelial dysfunction associated with elevated Aβ indicates the potential for endothelin receptor antagonists in the treatment of AD. It has already been demonstrated that the endothelin receptor antagonist bosentan, preserves aortic and carotid endothelial function in Tg2576 mice, and our findings suggest that endothelin receptor antagonists may be beneficial in maintaining CBF in AD.

RAGE and Abeta immunoglobulins: relation to Alzheimer's disease-related cognitive function

The immunoglobulins (IgGs) for beta amyloid (Abeta) and receptors for the advanced glycation end products (RAGE) have previously been shown to be related to memory and language measures in a mixed neurological sample of older adults. In this study, we examined group differences in Abeta and RAGE IgGs, as well as the relationship between both IgGs and cognitive performance in nondiabetic older adults with normal cognition, mild cognitive impairment (MCI), and probable Alzheimer's disease (AD). We found RAGE and Abeta levels to be elevated in some AD participants, leading to significant AD-control group differences. While there was an overall correlation between both IgG levels and global cognition across all three groups, this relationship was largely attributable to group differences in cognition, highlighted by considerable variability within groups in the relationship between IgG levels and cognition. While findings do not support a consistent relationship between cognition and either IgG, further research with larger samples is needed to better characterize cognitive differences between AD participants with high versus low Abeta and RAGE titers.

Multivariate analysis of differential lymphocyte cell cycle activity in Alzheimer's disease

Mounting evidence suggests cell cycle dysregulation is involved in the pathogenesis of Alzheimer's disease (AD) and that this failure is systemic, affecting not only neurons but also peripheral blood lymphocytes (PBLs). This study analyzed if differences in PBL proliferation activity could be used as a diagnostic biomarker for AD. CD69 and CD28 expressions on PBL T, B, and monocyte cells were measured by flow cytometry with and without mitogenic stimulation in healthy controls (HC), probable AD, and Parkinson's disease dementia (PDD) subjects. Univariate and multivariate scoring models were employed to evaluate the data relative to the clinical diagnoses. Eleven CD expression markers were significantly altered in AD subjects compared with a mixed pool of PDD and HC subjects using univariate models. Using multivariate models, seven CD expression markers were significantly altered in AD subjects compared with PDD subjects. Multivariate scoring demonstrated up to a 91% positive and 92% negative agreement with subject clinical diagnosis and had little correlation with the severity of dementia. Present findings suggest that with further development this analytical and multivariate modeling procedure could aid the current differential diagnosis of Alzheimer's disease.

What do Korean American immigrants know about Alzheimer's disease (AD)? The impact of acculturation and exposure to the disease on AD knowledge

OBJECTIVE

The present study examined knowledge of Alzheimer's disease (AD) and factors related to the disease knowledge among Korean American immigrants.

METHODS

Two-hundred and nine middle-aged and older Korean American immigrants completed a self-administered questionnaire.

RESULTS

Korean American immigrants had strong stigma about AD and interpreted the disease as a form of insanity. They considered memory loss and AD as a part of the aging process. They seriously lacked knowledge about the treatment, diagnosis and cause of AD. Those who were less acculturated and less exposed to AD were likely to have poorer AD knowledge.

CONCLUSIONS

There is a need to expand AD education efforts among Korean American immigrants because the views of stigmatization and normalization of AD combined with certain Asian cultural norms can be barriers to early recognition and intervention. Our study suggests knowledge areas of concentration in AD education and a segment of the population that AD education should target. Further research on symptom knowledge by the disease stages and causal beliefs is needed to better understand the existing views about AD in Korean American immigrants.

Improving access to dementia care: development and evaluation of a rural and remote memory clinic

The availability, accessibility and acceptability of services are critical factors in rural health service delivery. In Canada, the aging population and the consequent increase in prevalence of dementia challenge the ability of many rural communities to provide specialized dementia care. This paper describes the development, operation and evaluation of an interdisciplinary memory clinic designed to improve access to diagnosis and management of early stage dementia for older persons living in rural and remote areas in the Canadian province of Saskatchewan. We describe the clinic structure, processes and clinical assessment, as well as the evaluation research design and instruments. Finally, we report the demographic characteristics and geographic distribution of individuals referred during the first three years.

Preventing beta-amyloid fibrillization and deposition: beta-sheet breakers and pathological chaperone inhibitors

Central to the pathogenesis of Alzheimer's disease (AD) is the conversion of normal, soluble beta-amyloid (sAbeta) to oligomeric, fibrillar Abeta. This process of conformational conversion can be influenced by interactions with other proteins that can stabilize the disease-associated state; these proteins have been termed 'pathological chaperones'. In a number of AD models, intervention that block soluble Abeta aggregation, including beta-sheet breakers, and compounds that block interactions with pathological chaperones, have been shown to be highly effective. When combined with early pathology detection, these therapeutic strategies hold great promise as effective and relatively toxicity free methods of preventing AD related pathology.

Perceptions of Illness, coping, and well-being in persons with mild cognitive impairment and their care partners

Despite greater attention to mild cognitive impairment (MCI), little is known about reactions to this potentially threatening diagnosis among persons with MCI (PWMCI) and their care partners. Psychologic reactions, perceptions of illness, and coping responses of 46 individuals recently diagnosed with MCI and 29 care partners were assessed with questionnaires assessing psychologic well-being, illness perceptions, coping, and perceived needs for services. Care partners and PWMCI report normal levels of psychologic well-being, showing less distress than is commonly found in Alzheimer disease (AD) caregivers. Problem-focused (eg, active coping) and emotion-focused coping strategies (eg, acceptance) were used more often than dysfunctional coping strategies (eg, self-distraction) by PWMCI and care partners. Both groups tended to minimize the likelihood of conversion to AD, and endorsed mental and physical exercise, optimism, dietary changes, and stress reduction as strategies to prevent conversion. Although PWMCI minimized their impairment, care partners reported providing an average of 24 hours per week of caregiving and reported that the PWMCI did need significant help with complex activities. Respondents reported using few formal services but they anticipate substantial future need for services. Results suggest that PWMCI and care partners are likely to minimize the threat of AD and to perceive that conversion is controllable and preventable with health promotion activities. Study implications for the development of intervention programs for PWMCI and their care partners are discussed.

Is computed tomography still useful as a neuroimaging tool in psychiatry?

BACKGROUND

Computed tomography (CT) has played a pivotal role in psychiatry from its inception; however with the advent of other high-resolution noninvasive neuroimaging techniques such as MRI, the field has gone through a dramatic transformation.

OBJECTIVE

This article will explore the current role of CT in psychiatry.

METHODS

An extensive search of the published literature (1970 - 2008) was conducted, employing a number of databases and terms relevant to CT and imaging.

RESULTS/CONCLUSION

At present CT is primarily used as a screening tool to exclude intracranial pathology. This is partly because it is widely available and less expensive than other imaging modalities. CT is unable to provide region-specific information like MRI and this has restricted its use in disorders in which functional disturbances are suspected, however it remains the preferred mode of investigation where gross structural abnormalities are suspected.

The ART of loss: Abeta imaging in the evaluation of Alzheimer's disease and other dementias

Molecular neuroimaging based on annihilation radiation tomographic (ART) techniques such as positron emission tomography (PET), in conjunction with related biomarkers in plasma and cerebrospinal fluid (CSF), are proving valuable in the early and differential diagnosis of Alzheimer's disease (AD). With the advent of new therapeutic strategies aimed at reducing beta-amyloid (Abeta) burden in the brain to potentially prevent or delay functional and irreversible cognitive loss, there is increased interest in developing agents that allow assessment of Abeta burden in vivo. Abeta burden as assessed by molecular imaging matches histopathological reports of Abeta plaque distribution in aging and dementia and appears more accurate than FDG for the diagnosis of AD. Abeta imaging is also a very powerful tool in the differential diagnosis of AD from fronto-temporal dementia (FTD). Although Abeta burden as assessed by PET does not correlate with measures of cognitive decline in AD, it does correlate with memory impairment and rate of memory decline in mild cognitive impairment (MCI) and healthy older subjects. Approximately 30% of asymptomatic controls present cortical (11)C-PiB retention. These observations suggest that Abeta deposition is not part of normal ageing, supporting the hypothesis that Abeta deposition occurs well before the onset of symptoms and is likely to represent preclinical AD. Further longitudinal observations are required to confirm this hypothesis and to better elucidate the role of Abeta deposition in the course of Alzheimer's disease.

Treatment options in Alzheimer's disease: maximizing benefit, managing expectations

Alzheimer's disease (AD) is becoming an increasingly heavy burden on the society of developed countries, and physicians now face the challenge of providing efficient treatment regimens to an ever-higher number of individuals affected by the disease. Currently approved anti-AD therapies - the cholinesterase inhibitors and the N-methyl-D-aspartate receptor antagonist memantine - offer modest symptomatic relief, which can be enhanced using combination therapy with both classes of drugs. Additionally, alternative therapies such as nonsteroidal anti-inflammatory drugs, vitamin E, selegiline, Ginkgo biloba extracts, estrogens, and statins, as well as behavioral and lifestyle changes, have been explored as therapeutic options. Until a therapy is developed that can prevent or reverse the disease, the optimal goal for effective AD management is to develop a treatment regimen that will yield maximum benefits for individual patients across multiple domains, including cognition, daily functioning, and behavior, and to provide realistic expectations for patients and caregivers throughout the course of the disease. This review provides a basic overview of approved AD therapies, discusses some pharmacologic and nonpharmacologic treatment strategies that are currently being investigated, and offers suggestions for optimizing treatment to fit the needs of individual patients.

Donepezil treatment of patients with severe Alzheimer's disease in a Japanese population: results from a 24-week, double-blind, placebo-controlled, randomized trial

BACKGROUND/AIMS

A 24-week, randomized, parallel-group, double-blind placebo-controlled study was conducted to evaluate the efficacy and tolerability of donepezil in severe Alzheimer's disease (AD).

METHODS

Patients with severe AD (Mini-Mental State Examination score 1-12; modified Hachinski Ischemic Score < or =6; Functional Assessment Staging > or =6) were enrolled in this study in Japan. A total of 325 patients were randomized to donepezil 5 mg/day (n = 110), donepezil 10 mg/day (n = 103) or placebo (n = 112). Primary outcome measures were change from baseline to endpoint in the Severe Impairment Battery (SIB) and Clinician's Interview-Based Impression of Change-plus caregiver input (CIBIC-plus) at the endpoint visit.

RESULTS

Donepezil 5 mg/day and 10 mg/day were significantly superior to placebo on the SIB, with a least-squares mean treatment difference of 6.7 and 9.0, respectively (p < 0.001 compared with placebo). CIBIC-plus analyses showed significant differences in favor of donepezil 10 mg/day over placebo at endpoint (p = 0.003). A statistically significant dose-response relationship was demonstrated with the SIB and CIBIC-plus. Donepezil was well tolerated.

CONCLUSION

This study confirmed the effectiveness of donepezil 10 mg/day in patients with severe AD and demonstrated a significant dose-response relationship. Donepezil at dosages of both 5 mg/day and 10 mg/day is safe and well tolerated in Japanese patients with severe AD.

Memory and cognition in preclinical dementia: what we know and what we do not know

This overview focuses on the cognitive transition between normal aging and dementia. Numerous studies indicate that individuals who will go on to develop dementia show cognitive deficits many years before the time at which a clinical diagnosis could be rendered. The degree of preclinical impairment is remarkably similar for tasks assessing episodic memory, executive functioning, and perceptual speed, consistent with the view that multiple brain alterations occur prior to clinical disease onset. Although most research in this area has dealt with Alzheimer disease (AD), several recent reports indicate that the pattern of preclinical impairment is very similar in the second largest dementia disorder, vascular dementia (VaD). This is important because currently the possibility for interventions to postpone disease onset is greater in VaD than in AD. Despite pronounced preclinical cognitive deficits in dementia, the performance distributions between cases and controls are largely overlapping, hampering the ability to identify high-risk individuals. To alleviate this problem, future research should evaluate hybrid models for the prediction of dementia. In such models, multiple indicators of cognitive functioning should be included along with markers from other domains that have been linked to subsequent dementia (such as brain imaging, genetics, and lifestyle variables). To the extent that these categories of variables add unique variance, classification accuracy will increase and the overlap in performance scores between incident cases and controls will decrease, thereby enhancing clinical usefulness. This approach would also facilitate the examination of interactive effects among classes of preclinical markers.

A 2-year follow-up of 233 very mild (CDR 0.5) Alzheimer's disease patients (REAL.FR cohort)

OBJECTIVES

Making an early diagnosis of Alzheimer's Disease (AD) is becoming increasingly important. The Clinical Dementia Rating scale (CDR), a semi-structured interview with patient and caregiver, is a global rating scale designed for use in staging dementia. The primary objective of our study was to examine the evolution of AD in individuals with very mild AD (CDR 0.5) across a 2-year follow up.

METHODS

A cohort of AD patients (n=682) living in the community were followed during 2 years in 16 centres of the French AD network. Each subject underwent extensive medical examination including the MMSE and CDR every 6 months.

RESULTS

Two hundred and thirty-three AD patients were rated CDR 0.5 at baseline (mean MMSE score: 23.15+/-2.57). They were younger and reported an average duration of symptoms of approximately 0.8 years less than patients with CDR >or= 1.During the 2-year follow-up, none of the AD CDR 0.5 subjects improved; 65% of them showed an increase in the CDR score. The rate of cognitive decline was similar between the AD CDR 0.5 and CDR >or= 1 groups. The ADL decline was more significant in patients with CDR >or= 1 at inclusion.

CONCLUSIONS

It is certainly possible to identify AD at a very early stage focusing on intra individual change in cognitive and functional impairment. Criteria with a high sensitivity and specificity for detecting AD at an early stage will help to further develop effective pharmacological and behavioural interventions for delaying the onset and progression of the disease.

[Stereology as a tool to estimate brain volume and cortical atrophy in elders with dementia]

INTRODUCTION

stereology is a body of methods that allow unbiased and efficient estimation of geometric quantities defined in arbitrary physical structures. In particular, stereology is a valuable tool to assist neuroimaging in the estimation of morphometric parameters in the brain. Therefore, stereology may confer objectivity in the complementary and diagnostic evaluation of dementia by adding disease by adding quantitative data to clinical evaluation.

OBJECTIVES AND METHODS

our purpose was to illustrate estimation of brain volume and pial surface area by means of quantitative, computer-assisted stereological methods. Both parameters were estimated by means of a vertical design with a single series of parallel Cavalieri sections at a random orientation and perpendicular to a fixed horizontal plane. The sections were obtained by magnetic resonance imaging. Suitable test systems (of test points for volume, and of cycloids for surface area) were superimposed on these sections with the aid of special software.

RESULTS

to explore the statistical error of the volume estimator due to stereological sampling, 5 or 10 systematic sections were used in combination with two test point densities in a ratio of 1:4, so that the workload varied in the proportions 1:2:4:8. The four resulting estimators varied between 986 and 1120 cm(3). The surface area estimators varied between 1947 and 2096 cm(2), with workloads varying in the proportions of 1:2:2.3:4.6.

CONCLUSIONS

stereology is a simple and efficient tool to obtain objective brain volume and surface area estimators that are unbiased by design and accurate at a modest cost. Thus the corresponding methods can effectively assist in diagnostic and follow-up evaluation of elders with dementia.

Longitudinal trajectories of cognitive change in preclinical Alzheimer's disease: a growth mixture modeling analysis

Preclinical Alzheimer's disease (AD) refers to a period of time prior to diagnosis during which cognitive deficits among individuals who will go on to receive a diagnosis of AD are present. There is great interest in describing the nature of cognitive change during the preclinical period, in terms of whether persons decline in a linear fashion to diagnosis, or exhibit some stability of functioning, followed by rapid losses in performance. In the current study we apply Growth Mixture Modeling to data from The Kungsholmen Project to evaluate whether decline in Mini Mental State Examination (MMSE) scores during the preclinical period of AD follows a linear or quadratic function. At the end of a 7-year follow-up period, some individuals would be diagnosed with AD (n=71), whereas others would remain free of dementia (n=457). The results indicated that a two-group quadratic model of decline provided the best statistical fit measures, as well as the greatest estimates of sensitivity (67%) and specificity (86%). Differences in MMSE scores were apparent at baseline, but the preclinical AD group began to experience precipitous declines three years prior to diagnosis. Finally, persons who were misclassified as preclinical AD had fewer years of education and poorer MMSE scores at baseline.

Depressed mood in informal caregivers of individuals with mild cognitive impairment

This study estimates the prevalence of depressed mood in caregivers of individuals with mild cognitive impairment (MCI) and assesses whether demographics, stressors, intrapsychic strain, and gain are associated with depressed mood. A secondary analysis of baseline data from the Alzheimer's Disease Cooperative Study MCI trial was conducted using a cross-sectional, correlational design. Descriptive statistics to estimate the prevalence of caregiver depressed mood and univariate and block-wise logistic regression analyses were used. The prevalence of depressed mood in 769 caregivers was 24.6% (95% confidence interval, 21.5-27.7). The odds of being depressed were significantly higher in younger, nonspousal caregivers with less education, who cared for MCI patients with lower activities of daily living functioning, and who perceived greater relational deprivation, higher levels of self-loss, and personal gain. Controlling for relevant variables, relational deprivation and caregiver education continued to be significantly associated with depressed mood. Relational deprivation may be important for future interventions.

Improving the quality of care for mild to moderate dementia: an evaluation of the Croydon Memory Service Model

BACKGROUND

The large majority of people with dementia receive nothing in the way of specialist assessment and care at any stage of their illness. There is a particular lack of services focussed on early identification and intervention in dementia where there is the possibility of long-term harm reduction for people with dementia and their family carers. We have developed a model of care that is complementary to local systems of health and social care (The Croydon Memory Service Model [CMSM]). This is a low-cost, high-throughput, generic service to enable early identification and intervention in dementia. It is a multi-agency approach with joint ownership by health services, social services and the voluntary sector with embedded specifically-tailored approaches to primary care and minority ethnic communities.

METHOD

We completed a service evaluation of the introduction of the CMSM in a single borough in South London. Six predefined service goals were set: high acceptability; high appropriate referral rate; successful engagement with people from minority ethnic groups; successful engagement with people with young onset dementia; focus on engagement with mild cases to enable early intervention; and an increase in the overall number of new cases of dementia seen. Mixed qualitative and quantitative methodologies were used including a description and 6-month follow-up of a cohort of 290 consecutive referrals.

RESULTS

All key predefined service goals were met: 95% acceptability; 94% appropriate referrals; successful engagement with minority ethnic groups (two-fold greater number compared with that expected from general population demographic data); 17% of referrals under 65 years of age; 68% referrals with mild or minimal dementia severity; and an estimated 63% increase in the number of new cases of dementia seen in Croydon. At 6-month follow up, those referred to the service had decreased behavioural disturbance and increased quality of life compared with baseline.

CONCLUSIONS

Specific services for early dementia, which deliver diagnosis and care, can be established. These services can increase the numbers of people with early dementia identified and provided with care. Those receiving such services appear to improve in terms of quality of life and behavioural and psychological symptoms of dementia. Next steps should include the establishment of such services in other representative areas and evaluation of their effectiveness in comparison with other models of care.

Quantitative MR imaging in Alzheimer disease

Alzheimer disease (AD) is the most common type of dementia. It currently affects approximately 4 million people in the United States. AD is a progressive neurodegenerative disorder characterized by the gradual deposition of neuritic plaques and neurofibrillary tangles in the brain, which is thought to occur decades before the onset of clinical symptoms. Identification of people at risk before the clinical appearance of dementia has become a priority due to the potential benefits of therapeutic intervention. Although atrophy of medial temporal lobe structures has been shown to correlate with progression of AD, a growing number of recent reports have indicated that such atrophy may not be specific to AD. To improve diagnostic specificity, new quantitative magnetic resonance (MR) imaging methods are being developed that exploit known pathogenic mechanisms exclusive to AD. This article reviews the MR techniques that are currently available for the diagnostic assessment of AD.

Longitudinal models of growth and survival applied to the early detection of Alzheimer's disease

This article explores new statistical methodologies for using longitudinal data in the early prediction of Alzheimer's disease (AD). Specifically, the authors examine some new techniques that allow the joint or "shared" estimation of longitudinal components based on both duration (survival) and quantitative changes (growth curves). These new shared growth-survival parameter models may be used to characterize the declining functions that anticipate the onset of AD. The authors apply these models to data from the Kungsholmen Project, a longitudinal study of aging in Stockholm, Sweden. They examine age-based survival-frailty models for the onset of AD, latent growth-decline curve models for changes in cognition over age, and 3 alternative forms of models for the shared relationships of survival and early cognitive decline. The accuracy and reliability of this approach is considered for a better understanding of the developmental course of AD in these data, including the potential removal of biases due to subject selection.

Stability and predictability of the classification of mild cognitive impairment as assessed by episodic memory test performance over time

This study aimed to address the criteria and the stability of the classification of MCI. The Foresight Challenge cohort of 157 community-dwelling volunteers was assessed on 3 visits at 2-year intervals with episodic, semantic and working memory tests. Subjective memory complaints were assessed with the CAMDEX. Of the cohort, 2% had dementia and 31% were classified with MCI at visit 3, 43% with stable impairment from Time 1. Thirteen percent of those with objective memory impairment at Time 1 or 2 improved to control status by Time 3. Episodic memory tests were predictive for MCI at all timepoints, as were tests for praxis and Graded Naming, while at Time 3 spatial span lost predictive value, but processing speed became predictive. Decline in processing speed was seen in control and MCI groups, while memory performance and MMSE decline occurred only in the MCI group. The use of combined memory test scores gave better sensitivity to MCI than single tests. Subjective memory complaints were positive for 79% of the MCI group and 62.5% of controls. These findings would suggest consideration of modification of current MCI criteria.