The role of physical and cognitive function in performance of activities of daily living in patients with mild-to-moderate Alzheimer's disease - a cross-sectional study.

BACKGROUND: Several factors may play a role in the ability of patients with Alzheimer's disease to perform activities of daily living (ADL). The aim of this study was to examine the impact of different aspects of physical performance and cognitive functions on ADL in patients suffering from mild-to-moderate Alzheimer's disease. METHODS: We conducted secondary analyses on cross-sectional baseline data from the randomized controlled multicentre study "Preserving quality of life, physical health and functional ability in Alzheimer's Disease: The effect of physical exercise" (ADEX). In total, 185 AD patients (76 women and 109 men), with a mean age on 70,4 years, were included. Data from physical performance tests (Astrand cycle test, Timed up & Go (TUG), Sit to Stand test (STS)) and cognitive tests (Mini Mental Status Examination (MMSE), Symbol Digit Modalities Test (SDMT), Stroop Color and Word test (Stroop)) were used. Their associations with ADL, measured on the ADCS-ADL scale was assessed in multivariable regression analyses. RESULTS: SDMT and MMSE had significant, moderate correlations with total ADL (SDMT: r = 0.33, MMSE: r = 0.42) and instrumental ADL (SDMT: r = 0.31, MMSE: r = 0.42), but not with basic ADL. Adjusting for age and sex, the associations between SDMT and MMSE to total ADL and instrumental ADL persisted. No significant associations were found between Astrand, TUG, STS or Stroop and total ADL, basic ADL or instrumental ADL. CONCLUSION: Total ADL and instrumental ADL are associated with cognitive functions, including executive function. No significant association between examined physical performance parameters and ADL functions was observed, and consequently does not support an impact of physical function on ADL functions in patients with mild-to-moderate Alzheimer's disease and relatively well-preserved physical function. Strategies aimed to improve cognition may be better suited to improve ADL function in patients with mild-to-moderate Alzheimer's disease. TRIAL REGISTRATION: NCT01681602 . Registered 10 September 2012, retrospectively registered.

Changes in the left temporal microstate are a sign of cognitive decline in patients with Alzheimer's disease.

INTRODUCTION: Large-scale brain networks are disrupted in the early stages of Alzheimer's disease (AD). Electroencephalography microstate analysis, a promising method for studying brain networks, parses EEG signals into topographies representing discrete, sequential network activations. Prior studies indicate that patients with AD show a pattern of global microstate disorganization. We investigated whether any specific microstate changes could be found in patients with AD and mild cognitive impairment (MCI) compared to healthy controls (HC). MATERIALS AND METHODS: Standard EEGs were obtained from 135 HC, 117 patients with MCI, and 117 patients with AD from six Nordic memory clinics. We parsed the data into four archetypal microstates. RESULTS: There was significantly increased duration, occurrence, and coverage of microstate A in patients with AD and MCI compared to HC. When looking at microstates in specific frequency bands, we found that microstate A was affected in delta (1-4 Hz), theta (4-8 Hz), and beta (13-30 Hz), while microstate D was affected only in the delta and theta bands. Microstate features were able to separate HC from AD with an accuracy of 69.8% and HC from MCI with an accuracy of 58.7%. CONCLUSIONS: Further studies are needed to evaluate whether microstates represent a valuable disease classifier. Overall, patients with AD and MCI, as compared to HC, show specific microstate alterations, which are limited to specific frequency bands. These alterations suggest disruption of large-scale cortical networks in AD and MCI, which may be limited to specific frequency bands.

Moderate- to high-intensity exercise does not modify cortical ß-amyloid in Alzheimer's disease.

INTRODUCTION: Animal models of Alzheimer's disease show that exercise may modify ß-amyloid (Aß) deposition. We examined the effect of a 16-week exercise intervention on cortical Aß in patients with mild-to-moderate Alzheimer's disease. METHODS: Thirty-six patients with Alzheimer's disease were randomized to either one hour of aerobic exercise three times weekly for 16 weeks or usual care. Pre and post intervention, 11Carbon-Pittsburgh compound B positron emission tomography was carried out to assess cortical Aß, and quantified using standardized uptake value rations (SUVRs). RESULTS: The intervention showed no effect on follow-up SUVRs in a covariance analysis with group allocation, baseline intervention SUVR, age, sex, and baseline Mini-Mental State Examination as predictors. Change in SUVRs did not correlate with changes in measures of physical or aerobic fitness. DISCUSSION: The present findings do not support an effect of exercise on Aß. However, the relatively short intervention period may account for a lack of efficacy. Further studies should test earlier and longer interventions.

Impact of a clinical decision support tool on prediction of progression in early-stage dementia: a prospective validation study.

BACKGROUND: In clinical practice, it is often difficult to predict which patients with cognitive complaints or impairment will progress or remain stable. We assessed the impact of using a clinical decision support system, the PredictND tool, to predict progression in patients with subjective cognitive decline (SCD) and mild cognitive impairment (MCI) in memory clinics. METHODS: In this prospective multicenter study, we included 429 patients with SCD (n = 230) and MCI (n = 199) (female 54%, age 67 ± 9, MMSE 28 ± 2) and followed them for at least 12 months. Based on all available patient baseline data (demographics, cognitive tests, cerebrospinal fluid biomarkers, and MRI), the PredictND tool provides a comprehensive overview of the data and a classification defining the likelihood of progression. At baseline, a clinician defined an expected follow-up diagnosis and estimated the level of confidence in their prediction using a visual analogue scale (VAS, 0-100%), first without and subsequently with the PredictND tool. As outcome measure, we defined clinical progression as progression from SCD to MCI or dementia, and from MCI to dementia. Correspondence between the expected and the actual clinical progression at follow-up defined the prognostic accuracy. RESULTS: After a mean follow-up time of 1.7 ± 0.4 years, 21 (9%) SCD and 63 (32%) MCI had progressed. When using the PredictND tool, the overall prognostic accuracy was unaffected (0.4%, 95%CI - 3.0%; + 3.9%; p = 0.79). However, restricting the analysis to patients with more certain classifications (n = 203), we found an increase of 3% in the accuracy (95%CI - 0.6%; + 6.5%; p = 0.11). Furthermore, for this subgroup, the tool alone showed a statistically significant increase in the prognostic accuracy compared to the evaluation without tool (6.4%, 95%CI 2.1%; 10.7%; p = 0.004). Specifically, the negative predictive value was high. Moreover, confidence in the prediction increased significantly (∆VAS = 4%, p < .0001). CONCLUSIONS: Adding the PredictND tool to the clinical evaluation increased clinicians' confidence. Furthermore, the results indicate that the tool has the potential to improve prediction of progression for patients with more certain classifications.

Moderate-to-High Intensity Physical Exercise in Patients with Alzheimer's Disease: A Randomized Controlled Trial.

BACKGROUND: Studies of physical exercise in patients with Alzheimer's disease (AD) are few and results have been inconsistent. OBJECTIVE: To assess the effects of a moderate-to-high intensity aerobic exercise program in patients with mild AD. METHODS: In a randomized controlled trial, we recruited 200 patients with mild AD to a supervised exercise group (60-min sessions three times a week for 16 weeks) or to a control group. Primary outcome was changed from baseline in cognitive performance estimated by Symbol Digit Modalities Test (SDMT) in the intention-to-treat (ITT) group. Secondary outcomes included changes in quality of life, ability to perform activities of daily living, and in neuropsychiatric and depressive symptoms. RESULTS: The ITT analysis showed no significant differences between intervention and control groups in change from baseline of SDMT, other cognitive tests, quality of life, or activities of daily living. The change from baseline in Neuropsychiatric Inventory differed significantly in favor of the intervention group (mean: -3.5, 95% confidence interval (CI) -5.8 to -1.3, p = 0.002). In subjects who adhered to the protocol, we found a significant effect on change from baseline in SDMT as compared with the control group (mean: 4.2, 95% CI 0.5 to 7.9, p = 0.028), suggesting a dose-response relationship between exercise and cognition. CONCLUSIONS: This is the first randomized controlled trial with supervised moderate-to-high intensity exercise in patients with mild AD. Exercise reduced neuropsychiatric symptoms in patients with mild AD, with possible additional benefits of preserved cognition in a subgroup of patients exercising with high attendance and intensity.

Striatal dopamine transporter binding does not correlate with clinical severity in dementia with Lewy bodies.

UNLABELLED: Patients who have dementia with Lewy bodies (DLB) show both clinical and histopathologic overlap with Alzheimer disease patients and Parkinson disease patients. In this study, we correlated the core features of DLB (dementia, parkinsonism, hallucinations, and fluctuations) with striatal dopamine transporter (DAT) availability as assessed with SPECT and (123)I-N-(3-iodoprop-2E-enyl)-2-ß-carbomethoxy-3ß-(4-methylphenyl) nortropane ((123)I-PE2I) in patients with newly diagnosed DLB. METHODS: Two hundred eighty-eight patients were consecutively included in the study as they were referred for diagnostic SPECT scanning of DAT with (123)I-PE2I. Of those patients, 51 had, on the basis of clinical guideline criteria, a probable-DLB diagnosis at follow-up 16 ± 11.6 mo later. Before or on the day of the SPECT scan, DLB patients had a routine neurologic examination including Hoehn and Yahr grading and were cognitively evaluated with the Mini Mental State Examination. RESULTS: There was no correlation between Mini Mental State Examination, Hoehn and Yahr score, fluctuations or hallucinations, and striatal DAT availability as measured with (123)I-PE2I and SPECT. CONCLUSION: In patients with newly diagnosed DLB, symptoms are not associated with a reduction in striatal DAT despite its firm involvement in DLB pathology.

Predictive value of dopamine transporter SPECT imaging with [¹²³I]PE2I in patients with subtle parkinsonian symptoms.

PURPOSE: To examine the diagnostic sensitivity and specificity of dopamine transporter SPECT imaging with a highly dopamine transporter selective radioligand. The study included consecutively enrolled, drug-naive patients with an average short history of parkinsonian motor symptoms, referred for diagnostic scanning. METHODS: The study group comprised 288 patients naive to antiparkinson treatment who were enrolled as they were admitted for a diagnostic SPECT scan with the radioligand [(123)I]-N-(3-iodoprop-2E-enyl)-2-ß-carbomethoxy-3ß-(4-methylphenyl)nortropane ((123)I-PE2I). After the diagnostic scanning, patients were followed clinically with an average follow-up of 19.7 ± 12.5 months. RESULTS: A diagnosis could be clinically settled in 189 patients and among these patients, a dopamine transporter scan had a sensitivity of 88% and a specificity of 91% for discrimination between patients with and without striatal neurodegeneration. In cognitively impaired patients (Mini Mental State Examination <27) the specificity was 75% and the sensitivity 95%. A striatal anterior-posterior ratio (APR) of >2 differentiated between idiopathic Parkinson's disease and atypical parkinsonian syndromes with a specificity of 84% and a sensitivity of 63%. CONCLUSION: In drug-naive patients with subtle clinical parkinsonian motor symptoms, dopamine transporter scan using (123)I-PE21 has a high sensitivity and specificity in distinguishing between patients with and without striatal neurodegeneration. The specificity is lower in patients who are also cognitively impaired. Calculation of the striatal APR can assist in differentiating between idiopathic Parkinson's disease and atypical parkinsonian syndromes.

Reduced CSF CART in dementia with Lewy bodies.

Dementia with Lewy bodies (DLB) is the second most common form of neurodegenerative dementia after Alzheimer's disease (AD). The underlying neurobiological mechanism of DLB is not fully understood and no generally accepted biomarkers are yet available for the diagnosis of DLB. In a recent MRI study, DLB patients displayed hypothalamic atrophy whereas this region was not affected in AD patients. Cocaine and amphetamine regulated transcript (CART) is a neuropeptide expressed selectively in neurons in the hypothalamus. Here, we found that CSF CART levels were significantly reduced by 30% in DLB patients (n = 12) compared to controls (n = 12) as well as to AD patients (n = 14) using radioimmunoassay. Our preliminary results suggest that reduced CSF CART is a sign of hypothalamic dysfunction in DLB and that it may serve as a biomarker for this patient group.

Patient versus informant reported quality of life in the earliest phases of Alzheimer's disease.

OBJECTIVES: The study investigated if patient and informant reported Quality of Life (QoL) differed in early Alzheimer's disease (AD). In addition, we examined whether anosognosia had an impact on the agreement between patient and informant ratings of QoL and whether anosognosia, dementia severity, depression and behavioural symptoms were significantly correlated to QoL in early AD. METHODS: From a prospective research program including newly referred patients (age >60 years and MMSE > or = 20), 48 patients with very early AD were included. QoL was assessed using the QoL-AD and EQ-5D scales. Anosognosia was rated on a categorical scale by an examiner. MMSE, Geriatric Depression Scale, Danish Adult Reading Test and Frontal Behavioural Inventory were also administered. RESULTS: On most QoL measures patients rated their QoL higher than their informants. Anosognosia was not associated with QoL but significantly with an inverse impact on the agreement between patient and informant ratings of QoL. Self-reported QoL was significantly correlated to depression but not to age, dementia severity, behavioural symptoms or memory impairment. Informant ratings of QoL were significantly correlated to behavioural symptoms and informant ratings on the EQ-5D Visual Analogue Scale were significantly correlated to patient reported depression. CONCLUSION: Patients with early AD generally reported higher QoL than their informants. This disagreement was associated with the presence of anosognosia. Self-reported QoL did not correlate with the MMSE score. Behavioural changes and depressive symptoms may be associated with low QoL.

Measuring morphological and cellular changes in Alzheimer's dementia: a review emphasizing stereology.

From a clinical as well as a neuropathological point of view Alzheimer's disease (AD) has been the focus of intense research for more than three decades. Most studies to identify morphometric correlates with the declining cognitive function in normal aging and AD have employed semi-quantitative methods to assess neuropathological markers such as neurofibrillary tangles, senile plaques, neuronal, or glial cell densities, and neuron sizes. To this end, many cell counting methods have employed two-dimensional designs in single sections, yielding estimates of cell numbers either as neuron densities (number of cell profiles per area) or estimates of the size distribution of neuron profiles in columns vertical to the cortical surface. This approach gives rise to difficulties in interpretation because of the three-dimensional size, shape, and orientation of the counted cells, and the effect of shrinkage artifacts. Modern stereological techniques offer a more rigorous approach for quantifying neuropathological changes associated with aging and degenerative disease. However the stereological studies also suffer from the limitations of high biological variability in AD-type neuropathology, and the relative scarcity of autopsied brains from well-studied non-demented comparison subjects. As a result, the clinicopathological associations between neuropathology and indices of cognitive performance in aging and AD are not yet firmly established. The requirement for the proper description of morphologic neuropathology of AD is clear: any macroscopic or microscopic abnormalities, are subtle and must consequently be demonstrated reproducibly in well-controlled studies. In this review we try to evaluate which, if any, of the contemporary claims for morphometric brain abnormalities in AD can be said to be well established, with special emphasis placed on human stereological post-mortal studies.