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The aim of the present study is to evaluate the diagnostic value of diffusion tensor imaging (DTI) for early Alzheimer's disease (AD) in comparison to widely accepted medial temporal lobe (MTL) atrophy measurements. A systematic literature research was performed into DTI and MTL atrophy in AD and mild cognitive impairment (MCI). We included seventy-six studies on MTL atrophy including 8,122 subjects and fifty-five DTI studies including 2,791 subjects. Outcome measure was the effect size (ES) expressed as Hedges g. In volumetric studies, atrophy of the MTL significantly differentiated between AD and controls (ES 1.32-1.98) and MCI and controls (ES 0.61-1.46). In DTI-Fractional anisotropy (FA) studies, the total cingulum differentiated best between AD and controls (ES = 1.73) and the parahippocampal cingulum between MCI and controls (ES = 0.97). In DTI-Mean diffusivity (MD) studies, the hippocampus differentiated best between AD and controls (ES = -1.17) and between MCI and controls (ES = -1.00). We can conclude that in general, the ES of volumetric MTL atrophy measurements was equal or larger than that of DTI measurements. However, for the comparison between controls and MCI-patients, ES of hippocampal MD was larger than ES of hippocampal volume. Furthermore, it seems that MD values have somewhat more discriminative power than FA values with higher ES in the frontal, parietal, occipital and temporal lobe. [ABSTRACT FROM AUTHOR]

Cerebrovascular dysfunction plays a role not only in vascular causes of cognitive impairment but also in Alzheimer's disease (AD). We hypothesized that cerebral autoregulation is impaired in patients with AD compared to subjects with mild cognitive impairment (MCI) and controls. Dynamic cerebral autoregulation (dCA) was investigated in 17 AD patients, 19 MCI subjects, and 20 controls (C). Groups were matched for age, gender, and level of education. Electrocardiogram and non-invasive finger arterial blood pressure were measured and transcranial doppler ultrasonography was used to measure cerebral blood flow velocity in right and left middle cerebral artery (MCA). Cerebrovascular resistance index (CVRi) was also computed. dCA in supine position was quantified based on spontaneous blood pressure variations by computation of the linear transfer function between arterial blood pressure and MCA cerebral blood flow velocity. dCA gain and phase were evaluated for different frequency bands. Results were also evaluated using a 3-parameter windkessel model (WKM). CVRi was significantly higher in AD (2.9 ± 0.2) compared to both MCI (2.3 ± 0.1, p = 0.02) and C (2.1 ± 0.1 mmHgs/cm, p = 0.002). Five MCI patients who converted to AD during the course of the study also had higher CVRi compared to non-converters (2.8 ± 0.6 versus 2.1 ± 0.5 mmHgs/cm, p < 0.05). No significant differences in dCA gain and phase were found. In terms of the WKM approach, in the order C→MCI→AD groups showed about equal arterial resistance and peripheral compliance, but increased peripheral vasculature resistance (26 ± 2 versus 36 ± 3 mmHgs/ml in C resp. AD, p = 0.004). In conclusion, AD patients compared to MCI patients and controls have increased CVRi, whereas dCA parameters do not seem to differentiate AD patients. For MCI patients, CVRi might have predictive value in developing AD. [ABSTRACT FROM AUTHOR]

Background: Quality of Life (QoL) is an important outcome measure in dementia, particularly in the context of interventions. Research investigating longitudinal QoL in dementia with Lewy bodies (DLB) is currently lacking., Objective: To investigate determinants and trajectories of QoL in DLB compared to Alzheimer's disease (AD) and controls., Methods: QoL was assessed annually in 138 individuals, using the EQ5D-utility-score (0-100) and the health-related Visual Analogue Scale (VAS, 0-100). Twenty-nine DLB patients (age 69±6), 68 AD patients (age 70±6), and 41 controls (age 70±5) were selected from the Dutch Parelsnoer Institute-Neurodegenerative diseases and Amsterdam Dementia Cohort. We examined clinical work-up over time as determinants of QoL, including cognitive tests, neuropsychiatric inventory, Geriatric Depression Scale (GDS), and disability assessment of dementia (DAD)., Results: Mixed models showed lower baseline VAS-scores in DLB compared to AD and controls (AD: β±SE = -7.6±2.8, controls: β±SE = -7.9±3.0, p < 0.05). An interaction between diagnosis and time since diagnosis indicated steeper decline on VAS-scores for AD patients compared to DLB patients (β±SE = 2.9±1.5, p < 0.1). EQ5D-utility-scores over time did not differ between groups. Higher GDS and lower DAD-scores were independently associated with lower QoL in dementia patients (GDS: VAS β±SE = -1.8±0.3, EQ5D-utility β±SE = -3.7±0.4; DAD: VAS = 0.1±0.0, EQ5D-utility β±SE = 0.1±0.1, p < 0.05). No associations between cognitive tests and QoL remained in the multivariate model., Conclusion: QoL is lower in DLB, while in AD QoL shows steeper decline as the disease advances. Our results indicate that non-cognitive symptoms, more than cognitive symptoms, are highly relevant as they impact QoL.

Background: Abnormal insulin signaling in the brain has been linked to Alzheimer's disease (AD)., Objective: To evaluate whether cerebrospinal fluid (CSF) insulin levels are associated with cognitive performance and CSF amyloid-β and Tau. Additionally, we explore whether any such association differs by sex or APOE ɛ4 genotype., Methods: From 258 individuals participating in the Parelsnoer Institute Neurodegenerative Diseases, a nationwide multicenter memory clinic population, we selected 138 individuals (mean age 66±9 years, 65.2% male) diagnosed with subjective cognitive impairment (n = 45), amnestic mild cognitive impairment (n = 44), or AD (n = 49), who completed a neuropsychological assessment, including tests of global cognition and memory performance, and who underwent lumbar puncture. We measured CSF levels of insulin, amyloid-β1-42, total (t-)Tau, and phosphorylated (p-)Tau., Results: CSF insulin levels did not differ between the diagnostic groups (p = 0.136). Across the whole study population, CSF insulin was unrelated to cognitive performance and CSF biomarkers of AD, after adjustment for age, sex, body mass index, diabetes status, and clinic site (all p≥0.131). Importantly, however, we observed effect modification by sex and APOE ɛ4 genotype. Specifically, among women, higher insulin levels in the CSF were associated with worse global cognition (standardized regression coefficient -0.483; p = 0.008) and higher p-Tau levels (0.353; p = 0.040). Among non-carriers of the APOE ɛ4 allele, higher CSF insulin was associated with higher t-Tau (0.287; p = 0.008) and p-Tau (0.246; p = 0.029)., Conclusion: Our findings provide further evidence for a relationship between brain insulin signaling and AD pathology. It also highlights the need to consider sex and APOE ɛ4 genotype when assessing the role of insulin.

Cerebral small vessel disease (cSVD) and amyloid-β (Aβ) deposition often co-exist in (prodromal) dementia, and both types of pathology have been associated with neurodegeneration. We examined whether cSVD and Aβ have independent or interactive effects on hippocampal volume (HV) in a memory clinic population. We included 87 individuals with clinical diagnoses of Alzheimer's disease (AD) (n = 24), mild cognitive impairment (MCI) (n = 26), and subjective cognitive complaints (SCC) (n = 37). cSVD magnetic resonance imaging markers included white matter hyperintensity (WMH) volume, lacunar infarct presence, and microbleed presence. Aβ pathology was assessed as cerebrospinal fluid-derived Aβ1 - 42 levels and dichotomized into normal or abnormal, and HV was determined by manual volumetric measurements. A linear hierarchical regression approach was applied for the detection of additive or interaction effects between cSVD and Aβ on HV in the total participant group (n = 87) and in the non-demented group (including SCC and MCI individuals only, n = 63). The results revealed that abnormal Aβ and lacunar infarct presence were independently associated with lower HV in the non-demented individuals. Interestingly, Aβ and WMH pathology interacted in the non-demented individuals, such that WMH had a negative effect on HV in individuals with abnormal CSF Aβ42 levels, but not in individuals with normal CSF Aβ42 levels. These associations were not present when individuals with AD were included in the analyses. Our observations suggest that relatively early on in the disease process older individuals with abnormal Aβ levels are at an increased risk of accelerated disease progression when concomitant cSVD is present.

Background: Neuropsychological testing has long been embedded in daily clinical practice at memory clinics but the added value of a complete neuropsychological assessment (NPA) to standard clinical evaluation is unknown., Objective: To evaluate the added diagnostic and prognostic value of NPA to clinical evaluation only in memory clinic patients., Methods: In 221 memory clinic patients of a prospective cohort study, clinical experts diagnosed clinical syndrome (subjective cognitive impairment (SCI), mild cognitive impairment (MCI), or dementia) and etiology (Alzheimer's disease (AD) or no AD), and provided a prognosis of disease course (decline or no decline) before and after results of NPA were made available. The reference standard was a panel consensus based on all clinical information at baseline and up to 2 follow-up assessments., Results: With NPA data available, clinicians changed their initial syndromal diagnosis in 22% of patients, and the etiological diagnosis as well as the prognosis in 15%. This led to an increase in correctly classified cases of 18% for syndromal diagnosis, 5% for etiological diagnosis, and 1% for prognosis. NPA data resulted in the largest improvement in patients initially classified as SCI (syndrome: 93.3% (n = 14) correctly reclassified, etiology: net reclassification improvement [NRI] = 0.61, prognosis: NRI = 0.13) or MCI (syndrome: 89.3% (n = 23) correctly reclassified, etiology: NRI = 0.17, prognosis: NRI = 0.14), while there was no improvement in patients with dementia (syndrome: 100% (n = 1) correctly reclassified, etiology: NRI = -0.05, prognosis: NRI = -0.06). Overall, inclusion of NPA in the diagnostic process increased confidence in all diagnoses with 6-7%., Conclusion: Administration of a complete NPA after standard clinical evaluation has added value for diagnosing cognitive syndrome and its underlying etiology in patients regarded as non-demented based on the first clinical impression.

Background: Limited information is available on short-term prognosis of Alzheimer's disease (AD) biomarkers in cerebrospinal fluid (CSF) in addition to routine diagnostic workup., Objective: This study aims to investigate the added prognostic value of AD CSF biomarkers., Methods: In a prospective cohort study, clinical experts predicted cognitive and functional symptoms in 114 memory clinic patients by assessing comprehensive routine diagnostic test information (patient history, and physical, neurological, psychiatric, neuropsychological, and MRI examinations), without and with CSF biomarkers. The reference standard was the 'observed clinically relevant decline' using baseline and 1- and 2-year follow-up information., Results: Decline over a 2-year period was observed in 51% of all participants (3% in SMC, 48% in MCI, 90% in mild dementia). In the total sample, the accuracy of predicted decline did not differ significantly between routine assessment without (79% correctly predicted) and with (74% correctly predicted) CSF biomarkers. Subgroup analyses revealed 25 (83%) correct predictions in SMC, 30 (68%) in MCI, and 35 (88%) in dementia without the use of CSF; and 21 (70%), 27 (61%), and 36 (90%), respectively, with the use of CSF in addition to the routine assessment., Conclusion: AD CSF biomarkers did not increase accuracy of 2-year prognosis of cognitive and functional decline when added to routine diagnostic workup. This suggests that the standard diagnostic workup without CSF biomarkers allows fairly accurate predictions for the short-term course of symptoms. Routine AD biomarkers in CSF have limited prognostic value over 2 years in persons with a suspected cognitive disorder.

Over the last few years, the use of new technologies for the support of elderly people and in particular dementia patients received increasing interest. We investigated the use of a video monitoring system for automatic event recognition for the assessment of instrumental activities of daily living (IADL) in dementia patients. Participants (19 healthy subjects (HC) and 19 mild cognitive impairment (MCI) patients) had to carry out a standardized scenario consisting of several IADLs such as making a phone call while they were recorded by 2D video cameras. After the recording session, data was processed by a platform of video signal analysis in order to extract kinematic parameters detecting activities undertaken by the participant. We compared our automated activity quality prediction as well as cognitive health prediction with direct observation annotation and neuropsychological assessment scores. With a sensitivity of 85.31% and a precision of 75.90%, the overall activities were correctly automatically detected. Activity frequency differed significantly between MCI and HC participants (p < 0.05). In all activities, differences in the execution time could be identified in the manually and automatically extracted data. We obtained statistically significant correlations between manually as automatically extracted parameters and neuropsychological test scores (p < 0.05). However, no significant differences were found between the groups according to the IADL scale. The results suggest that it is possible to assess IADL functioning with the help of an automatic video monitoring system and that even based on the extracted data, significant group differences can be obtained.

Background: The relation between psychological distress, personality traits, and cognitive decline in cognitively impaired patients remains unclear., Objective: To investigate the effect of psychological distress and personality traits on cognitive functioning in subjects with mild cognitive impairment (MCI); and to investigate the predictive accuracy of these factors for the development of dementia., Methods: MCI patients (n = 343, age: 60.9±9.9 years, 38% female, and MMSE score: 28.1±1.9) were included from the Maastricht memory clinic. All patients underwent a standardized neuropsychological assessment (including tests for measuring mental speed (Trail Making Test (TMT) part A and Stroop Color Word Test (SCWT) part I), executive functioning (TMT part B and SCWT part III), memory (15-Word Learning Tests), and verbal fluency (1-minute animals)), CT or MRI, and blood assessment. The Dutch Personality Questionnaire (DPQ) and the 90-items Symptom Check List (SCL-90) were used to measure personality traits and psychological distress. Conversion to dementia was assessed two, five, and ten years after baseline. The mean follow-up period was 6.7±3.4 years., Results: The Psychoneuroticism score of the SCL-90 was associated with slower performances on SCWT part I and TMT part A. The subdomain Neuroticism of the DPQ was also associated with slower scores on the TMT part A. At follow-up, 85 (25.9%) subjects had developed dementia. The SCL-90 total score, and the subscales, Anxiety, Somatization, Insufficiency in thought and action, and Sleeping problems were associated with a decreased risk for developing (AD-type) dementia., Conclusion: Psychological distress negatively affected information processing speed, but was not associated with an increased risk of developing dementia in patients with MCI.

Co-morbidity and frailty are common in Alzheimer's disease (AD) and may contribute to the heterogeneity in clinical manifestations of the disease. We cross-sectionally investigated whether co-morbidity and frailty were independently associated with the clinical manifestation of AD in the 4C-Dementia study; a multicenter, longitudinal study in newly diagnosed AD patients. Clinical manifestation was operationalized using a composite of cognitive performance (neuropsychological assessment), activities of daily living (Disability Assessment for Dementia; DAD) and neuropsychiatric symptoms (Neuropsychiatric Inventory). As predictors of prime interest, co-morbidity was determined using the Cumulative Illness Rating Scale (CIRS-G) and frailty by the Fried criteria. In total, 213 AD patients participated (mean age 75 ± 10 years; 58% females). In linear regression models adjusted for age, gender, education, and disease duration, CIRS-G (β = -0.21, p < 0.01) and frailty (β = -0.34, p < 0.001) were separately associated with clinical AD manifestation. However, CIRS-G (β = -0.12, p = 0.12) lost statistical significance when both were combined (frailty: β = -0.31, p < 0.001). Models with the individual components of clinical AD manifestation as dependent variables show significant associations between cognitive performance and CIRS-G (β = -0.22, p = 0.01), and between DAD and frailty (β = -0.37, p < 0.001). Our findings indicate that physical health and clinical AD manifestation are associated. This association may be responsible for part of the heterogeneity in the presentation of AD. This emphasizes the importance of adequate assessment of co-morbid medical conditions and frailty in patients with AD.

White matter hyperintensities are associated with an increased risk of Alzheimer's disease (AD). White matter hyperintensities are believed to disconnect brain areas. We examined the topographical association between white matter hyperintensities and cortical thickness in controls, mild cognitive impairment (MCI), and AD patients. We examined associations between white matter hyperintensities and cortical thickness among 18 older cognitively healthy participants, 18 amnestic MCI, and 17 mild AD patients. These associations were cluster-size corrected for multiple comparisons. In controls, a positive association between white matter hyperintensities and cortical thickness was found in lateral temporal gyri. In MCI patients, white matter hyperintensities were positively related to cortical thickness in frontal, temporal, and parietal areas. Positive associations between white matter hyperintensities and cortical thickness in AD patients were confined to parietal areas. The results of the interaction group by white matter hyperintensities on cortical thickness were consistent with the findings of positive associations in the parietal lobe for MCI and AD patients separately. In the frontal areas, controls and AD patients showed inverse associations between white matter hyperintensities and cortical thickness, while MCI patients still showed a positive association. These results suggest that a paradoxical relationship between white matter hyperintensities and cortical thickness could be a consequence of neuroinflammatory processes induced by AD-pathology and white matter hyperintensities. Alternatively, it might reflect a region-specific and disease-stage dependent compensatory hypertrophy in response to a compromised network.