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While APOE ɛ4 is the major genetic risk factor for Alzheimer’s disease (AD), amyloid dysmetabolism is an initial or early event predicting clinical disease and is an important focus for secondary intervention trials. To improve identification of cases with increased AD risk, we evaluated recruitment procedures using pathological CSF concentrations of Aβ42 (pAβ) and APOE ɛ4 as risk markers in a multi-center study in Norway. In total, 490 subjects aged 40–80 y were included after response to advertisements and media coverage or memory clinics referrals. Controls (n = 164) were classified as normal controls without first-degree relatives with dementia (NC), normal controls with first-degree relatives with dementia (NCFD), or controls scoring below norms on cognitive screening. Patients (n = 301) were classified as subjective cognitive decline or mild cognitive impairment. Subjects underwent a clinical and cognitive examination and MRI according to standardized protocols. Core biomarkers in CSF from 411 and APOE genotype from 445 subjects were obtained. Cases (both self-referrals (n = 180) and memory clinics referrals (n = 87)) had increased fractions of pAβ and APOE ɛ4 frequency compared to NC. Also, NCFD had higher APOE ɛ4 frequencies without increased fraction of pAβ compared to NC, and cases recruited from memory clinics had higher fractions of pAβ and APOE ɛ4 frequency than self-referred. This study shows that memory clinic referrals are pAβ enriched, whereas self-referred and NCFD cases more frequently are pAβ negative but at risk (APOE ɛ4 positive), suitable for primary intervention.

Background: Neuropsychological comparisons between patients with mild cognitive impairment due to Parkinson’s disease (MCI-PD) and Alzheimer’s disease (MCI-AD) is mostly based on indirect comparison of patients with these disorders and normal controls (NC). Objective: The focus of this study was to make a direct comparison between patients with these diseases. Methods: The study compared 13 patients with MCI-PD and 19 patients with MCI-AD with similar age, education and gender. The participants were recruited and assessed at the same university clinic with equal methods. Results: The main finding was that on group level, MCI-AD scored significantly poorer on learning and memory tests than MCI-PD, whereas MCI-PD were impaired on 1 of 3 measures of executive functioning. Conclusion: MCI-AD performed poorer learning and memory tests, whereas MCI-PD only scored below the employed cut-off on one single executive test. In general, MCI-PD was noticeably less cognitively impaired than MCI-AD.

Introduction: Cognitive impairment in early Parkinson's disease (PD) is common and distinct from early Alzheimer's disease. Predictors and mechanisms are only partially known, but a-synuclein, amyloid-b and tau dysmetabolism may be involved. Our aim was to study associations between cerebrospinal fluid biomarkers (CSF) and cognition in non-dementia PD compared to normal controls (NC) and non-PD patients with mild cognitive impairment (MCI non-PD). Methods: Patients were classified as having normal, subjective or mild cognitive impairment after cognitive screening. CSF levels of total a-synuclein (t-a-syn), amyloid-b (Ab) 38, 40 and 42, total tau (Ttau) and phosphorylated tau (P-tau) were measured in 34 NC, 31 early, non-dementia PD and 28 MCI non-PD patients. A well validated neuropsychological test battery was administered. Results: In the PD group,13 had normal cognition, 4 had subjective and 14 mild cognitive impairment. PD patients had significantly lower CSF biomarker levels of t-a-syn, Ab38, 40 and 42, T-tau and P-tau compared to NC. Compared to MCI non-PD, t-a-syn, Ab38 and 40, T-tau and P-tau were also lower, while Ab42 was significantly higher in the PD group. Ab38 and 40 correlated strongly with t-a-syn levels in PD. Lower Ab42 was associated with decreased verbal learning, delayed verbal recall and response inhibition in PD. Conclusion: While Ab38, 40 and t-a-syn levels are strongly correlated, only lower Ab42 was associated with reduced cognitive functions in early PD, mainly connected to medial temporal lobe-based cognitive functions.

To investigate putative interacting or distinct pathways for hippocampal complex substructure (HCS) atrophy and cognitive affection in early-stage Alzheimer's disease (AD) and cerebrovascular disease (CVD), we recruited healthy controls, patients with mild cognitive impairment (MCI) and poststroke patients. HCSs were segmented, and quantitative white-matter hyperintensity (WMH) load and cerebrospinal fluid (CSF) amyloid-β concentrations were determined. The WMH load was higher poststroke. All examined HCSs were smaller in amyloid-positive MCI than in controls, and the subicular regions were smaller poststroke. Memory was reduced in amyloid-positive MCI, and psychomotor speed and executive function were reduced in poststroke and amyloid-positive MCI. Size of several HCS correlated with WMH load poststroke and with CSF amyloid-β concentrations in MCI. In poststroke and amyloid-positive MCI, neuropsychological function correlated with WMH load and hippocampal volume. There are similar patterns of HCS atrophy in CVD and early-stage AD, but different HCS associations with WMH and CSF biomarkers. WMHs add to hippocampal atrophy and the archetypal AD deficit delayed recall. In line with mounting evidence of a mechanistic link between primary AD pathology and CVD, these additive effects suggest interacting pathologic processes.

Background:Neuropsychiatric symptoms (NPS), such as depression, apathy, agitation, and psychotic symptoms are common in mild cognitive impairment (MCI) and dementia in Alzheimer's disease (AD). Subgroups of NPS have been reported. Yet the relationship of NPS and their subgroups to different stages of cognitive impairment is unclear. Most previous studies are based on small sample sizes and show conflicting results. We sought to examine the frequency of NPS and their subgroups in MCI and different stages of dementia in AD.Methods:This was a cross-sectional study using data from a Norwegian national registry of memory clinics. From a total sample of 4,571 patients, we included those with MCI or AD (MCI 817, mild AD 883, moderate–severe AD 441). To compare variables across groups ANOVA or χ2-test was applied. We used factor analysis of Neuropsychiatric Inventory Questionnaire (NPI-Q) items to identify subgroups of NPS.Results:The frequency of any NPS was 87.2% (AD 91.2%, MCI 79.5%; p < 0.001) and increased with increasing severity of cognitive decline. The most frequent NPS in MCI was depression. Apathy was the most frequent NPS in AD across different stages of severity. The factor analysis identified three subgroups in MCI and mild AD, and a fourth one in moderate–severe AD. We labelled the subgroups “depression,” “agitation,” “psychosis,” and “elation.”Conclusions:The frequency of NPS is high in MCI and AD and increases with the severity of cognitive decline. The subgroups of NPS were relatively consistent from MCI to moderate-severe AD. The subgroup elation appeared only in moderate-severe AD.

Objective Cognitive impairment is frequent in Parkinson's disease, but the underlying mechanisms are insufficiently understood. Because cortical metabolism is reduced in Parkinson's disease and closely associated with cognitive impairment, and CSF amyloid‐β species are reduced and correlate with neuropsychological performance in Parkinson's disease, and amyloid‐β release to interstitial fluid may be related to synaptic activity; we hypothesize that synapse dysfunction links cortical hypometabolism, reduced CSF amyloid‐β, and presynaptic deposits of α‐synuclein. We expect a correlation between hypometabolism, CSF amyloid‐β, and the synapse related‐markers CSF neurogranin and α‐synuclein. Methods Thirty patients with mild‐to‐moderate Parkinson's disease and 26 healthy controls underwent a clinical assessment, lumbar puncture, MRI, 18F‐fludeoxyglucose‐PET, and a neuropsychological test battery (repeated for the patients after 2 years). Results All subjects had CSF amyloid‐β 1‐42 within normal range. In Parkinson's disease, we found strong significant correlations between cortical glucose metabolism, CSF Aβ, α‐synuclein, and neurogranin. All PET CSF biomarker‐based cortical clusters correlated strongly with cognitive parameters. CSF neurogranin levels were significantly lower in mild‐to‐moderate Parkinson's disease compared to controls, correlated with amyloid‐β and α‐synuclein, and with motor stage. There was little change in cognition after 2 years, but the cognitive tests that were significantly different, were also significantly associated with cortical metabolism. No such correlations were found in the control group. Interpretation CSF Aβ, α‐synuclein, and neurogranin concentrations are related to cortical metabolism and cognitive decline. Synaptic dysfunction due to Aβ and α‐synuclein dysmetabolism may be central in the evolution of cognitive impairment in Parkinson's disease.

Objective To test the hypothesis that depressive symptoms correlate with Alzheimer's disease (AD) type changes in CSF and structural and functional imaging including hippocampus volume, cortical thickness, white matter lesions, Diffusion tensor imaging (DTI), and fluoro-deoxy-glucose positron emission tomography (FDG-PET) in patient with subjective (SCI) and mild (MCI) cognitive impairment. Method In 60 patients, depressive symptoms were assessed using the Geriatric Depression Scale. The subjects underwent MRI, 18F-FDG PET imaging, and lumbar CSF extraction. Results Subjects with depressive symptoms (n = 24) did not have more pathological AD biomarkers than non-depressed. Uncorrected there were trends towards larger hippocampal volumes (P = 0.06), less orbital WM damage measured by DTI (P = 0.10), and higher orbital glucose metabolism (P = 0.02) in the depressed group. The findings were similar when SCI and MCI were analyzed separately. Similarly, in patients with pathological CSF biomarkers (i.e., predementia AD, n = 24), we found that correlations between scores on GDS and CSF As42 and P-tau indicated less severe AD-specific CSF changes with increasing depression. Conclusion Depressive symptoms are common in SCI/MCI, but are not associated with pathological imaging or CSF biomarkers of AD. Depression can explain cognitive impairment in SCI/MCI or add to cognitive impairment leading to an earlier clinical investigation in predementia AD.

Aims: To improve early diagnosis of dementia disease, this study investigates correlates of cognitive complaints and cognitive test performance in patients with subjective (SCI) and mild (MCI) cognitive impairment. Methods: Seventy patients from a memory clinic, aged 45-79, with a score of 2 (n = 23) or 3 (n = 47) on the Global Deterioration Scale, were included. CSF biomarkers [Aβ42, total tau (T-tau) and phosphorylated tau (P-tau)], depressive symptoms, cognitive performance, and complaints were examined. Results: Correlation analysis showed that cognitive complaints increased with decreasing cognitive performance in SCI and decreased with decreasing performance in MCI. Linear regression models revealed that cognitive complaints were associated with depressive symptoms in both groups of patients, while cognitive performance was associated with CSF Aβ42 and P-tau in SCI and with T-tau and P-tau in MCI. Conclusion: These results suggest that depressive symptoms are associated with cognitive complaints, while degenerative changes are associated with objective cognitive decline in high-risk predementia states.

Neuropathological correlates of Alzheimer's disease (AD) emerge years before dementia. Biomarkers preceding cognitive decline and reflecting the causative processes can potentially aid early intervention and diagnosis. Diffusion tensor imaging (DTI) indirectly reflects tissue microstructure. To answer whether DTI is an early biomarker for AD and to explore the relationship between DTI and the established biomarkers of medial temporal lobe atrophy and cerebrospinal fluid (CSF) Aβ(42), T-tau, and P-tau, we longitudinally studied normal controls and patients with subjective (SCI) or mild (MCI) cognitive impairment. 21 controls and 64 SCI or MCI cases recruited from a university-hospital based memory clinic were re-examined after two to three years. FreeSurfer was used for longitudinal processing of morphometric data, and DTI derived fractional anisotropy, radial diffusivity, and mean diffusivity were analyzed in Tract-Based Spatial Statistics. Using regression models, we explored and compared the predictive powers of DTI and CSF biomarkers in regard to cognitive change and atrophy of the medial temporal lobe. Both DTI and CSF biomarkers significantly predicted cognitive decline and atrophy in the medial temporal lobe. In this population, however, DTI was a better predictor of dementia and AD-specific medial temporal lobe atrophy than the CSF biomarkers. The case for DTI as an early biomarker for AD is strengthened, but further studies are needed to confirm these results.

Background Psychosis is common in Parkinson's disease, and occurs with increasing frequency as the disease progresses. Assessment and treatment are often complicated and involve several clinical specialists in addition to the general practitioner. We describe the prevalence, form, causes and treatment of psychosis in Parkinson's disease. Material and method The article is based on a literature search in PubMed for controlled pharmacological treatment studies and a discretionary selection of articles based on the authors' clinical and research experience. Results About 1 % of patients with newly diagnosed Parkinson's disease have psychotic symptoms. In later stages, complicated by dementia, these symptoms occur in about half of the patients. A false sense of presence, optical illusions and visual hallucinations occur most frequently, but delusions and hallucinations involving other senses have been reported. Various theories to explain the underlying etiology and pathology are explored. A further medical assessment is recommended when psychotic symptoms occur. Clozapine is still the only antipsychotic drug documented effective against psychotic symptoms in Parkinson's disease. Interpretation The prevalence of psychotic symptoms in various stages of Parkinson''s disease has been thoroughly documented. Non-pharmacological treatment is often effective, but the documentation is inadequate. Pharmacological treatment with clozapine has proved effective against psychosis in Parkinson's disease, but new drugs that are easier to administer are needed.

Cognition is often affected early in Parkinson’s disease (PD). Lewy body and amyloid β (Aβ) pathology and cortical atrophy may be involved. The aim of this study was to examine whether medial temporal lobe structural changes may be linked to cerebrospinal fluid (CSF) biomarker levels and cognition in early PD. PD patients had smaller volumes of total hippocampus, presubiculum, subiculum, CA2–3, CA4-DG, and hippocampal tail compared with normal controls (NCs). In the PD group, lower CSF Aβ38 and 42 were significant predictors for thinner perirhinal cortex. Lower Aβ42 and smaller presubiculum and subiculum predicted poorer verbal learning and delayed verbal recall. Smaller total hippocampus, presubiculum and subiculum predicted poorer visuospatial copying. Lower Aβ38 and 40 and thinner perirhinal cortex predicted poorer delayed visual reproduction. In conclusion, smaller volumes of hippocampal subfields and subhippocampal cortex thickness linked to lower CSF Aβ levels may contribute to cognitive impairment in early PD. Thirty-three early PD patients (13 without, 5 with subjective, and 15 with mild cognitive impairment) and NC had 3 T magnetic resonance imaging (MRI) scans. The MRI scans were post processed for volumes of hippocampal subfields and entorhinal and perirhinal cortical thickness. Lumbar puncture for CSF biomarkers Aβ38, 40, 42, total tau, phosphorylated tau (Innogenetics), and total α-synuclein (Meso Scale Diagnostics) were performed. Multiple regression analyses were used for between-group comparisons of the MRI measurements in the NC and PD groups and for assessment of CSF biomarkers and neuropsychological tests in relation to morphometry in the PD group. Selective deterioration of key brain regions and biomarkers of neurodegeneration are linked with cognitive decline in Parkinson’s disease. Cognitive impairment is common in patients with this disease but the mechanisms behind it are unclear. Ane Lovli Stav at Akershus University Hospital, Norway, and colleagues used magnetic resonance imaging to study anatomical changes in the brains of early Parkinson’s patients without dementia. They found that the hippocampus, a brain region involved in memory, and discrete subregions within it were smaller in Parkinson’s patients. Next, they investigated certain neurodegeneration-linked biomarker proteins in the cerebrospinal fluid of Parkinson’s patients. The team showed that the anatomical brain changes were linked to both the expression levels of these proteins and cognitive problems that they observed in patients. The team’s findings should contribute to new diagnostic tests and therapies.

Objective: We used diffusion tensor imaging (DTI) to test the following hypotheses: (1) there is decreased white matter (WM) integrity in non-demented Parkinson’s disease (PD), (2) WM integrity is differentially reduced in PD and early Alzheimer’s disease (AD) and (3) DTI changes in non-demented PD are specifically associated with cognitive performance. Methods: This study included 18 non-demented patients with PD, 18 patients with mild cognitive impairment due to incipient AD and 19 healthy elderly normal control (NC) participants in a cross-sectional design. The participants underwent DTI, and tractbased spatial statistics was used to analyse and extract radial diffusivity and fractional anisotropy. Correlations between scores from a battery of neuropsychological tests and DTI were performed in the PD group. Results: Patients with PD had significant differences in DTI in WM underlying the temporal, parietal and occipital cortex as compared with NC. There were no significant differences between the PD and AD groups in the primary region of interest analyses, but compared with NC there was a tendency for more anterior changes in AD in contrast to more posterior changes in PD. In a secondary whole-brain analysis there were frontoparietal areas with significant differences between AD and PD. In patients with PD, there were significant correlations between DTI parameters in WM underlying the prefrontal cortex and executive and visuospatial abilities. Conclusions: In early, non-demented PD we found reduced WM integrity underlying the temporal, parietal and occipital cortices. In addition, WM integrity changes in prefrontal areas were associated with executive and visuospatial ability. These findings support that DTI may be an important biomarker in early PD, and that WM changes are related to cognitive impairment in PD.

Psychosis is common in Parkinson's disease, and occurs with increasing frequency as the disease progresses. Assessment and treatment are often complicated and involve several clinical specialists in addition to the general practitioner. We describe the prevalence, form, causes and treatment of psychosis in Parkinson's disease.The article is based on a literature search in PubMed for controlled pharmacological treatment studies and a discretionary selection of articles based on the authors' clinical and research experience.About 1 % of patients with newly diagnosed Parkinson's disease have psychotic symptoms. In later stages, complicated by dementia, these symptoms occur in about half of the patients. A false sense of presence, optical illusions and visual hallucinations occur most frequently, but delusions and hallucinations involving other senses have been reported. Various theories to explain the underlying etiology and pathology are explored. A further medical assessment is recommended when psychotic symptoms occur. Clozapine is still the only antipsychotic drug documented effective against psychotic symptoms in Parkinson's disease.The prevalence of psychotic symptoms in various stages of Parkinson''s disease has been thoroughly documented. Non-pharmacological treatment is often effective, but the documentation is inadequate. Pharmacological treatment with clozapine has proved effective against psychosis in Parkinson's disease, but new drugs that are easier to administer are needed.

Background/Aims: To explore the presenting and early symptoms of dementia with Lewy bodies (DLB). Method: Patients with mild dementia fulfilling diagnostic criteria for DLB (n = 61) and Alzheimer’s disease (AD) (n = 109) were recruited from outpatient dementia clinics in western Norway. At diagnosis, caregivers were asked which symptom had been the presenting symptom of dementia. Results: Caregivers reported that memory impairment was the most common presenting symptom in DLB (57%), followed by visual hallucinations (44%), depression (34%), problem solving difficulties (33%), gait problems (28%), and tremor/stiffness (25%). In contrast, 99% of AD carers reported impaired memory as a presenting symptom, whereas visual hallucinations were a presenting symptom in 3% of the AD cases. Conclusion: DLB should be suspected in predementia cases with visual hallucinations.