White matter hyperintensities and the course of depressive symptoms in elderly people with mild dementia

Association of Cerebrovascular Imaging Biomarkers, Depression, and Anxiety, with Mild Cognitive Impairment

The study included 1,738 Mayo Clinic Study of Aging participants (≥50 years old; 1,460 cognitively unimpaired and 278 with mild cognitive impairment (MCI)) and examined the cross-sectional association between cerebrovascular (CVD) imaging biomarkers (e.g., white matter hyperintensities (WMH), infarctions) and Beck Depression Inventory-II (BDI-II) and Beck Anxiety Inventory (BAI) scores, as well as their association with MCI. High (abnormal) WMH burden was significantly associated with having BDI-II>13 and BAI > 7 scores, and both (CVD imaging biomarkers and depression/anxiety) were significantly associated with MCI when included simultaneously in the model, suggesting that both were independently associated with the odds of MCI.

Executive function deficits and medial temporal lobe atrophy in late-life depression and Alzheimer's disease: a comparative study

Objectives

Alzheimer's disease (AD) and late-life depression (LLD) frequently exhibit executive function deficits (EFD) and medial temporal lobe atrophy (MTA) as shared characteristics. The objective of this research was to examine the utility of the Trail Making Test (TMT) and the MTA scale in distinguishing between LLD and AD.

Methods

A study of 100 patients, 50 with AD and 50 with LLD, was conducted using a cross-sectional design. The individuals were subjected to clinical evaluations to assess their level of depression and overall cognitive abilities, which included the Geriatric Depression Scale (GDS), Mini-Mental State Examination (MMSE), and Montreal Cognitive Assessment (MoCA). We evaluated executive function deficits (EFD) through the use of the TMT, which includes both TMT-A and TMT-B. MTA was measured using magnetic resonance imaging. To evaluate the ability of TMT and MTA scale to distinguish between the two groups, a receiver operating characteristic (ROC) curve was utilized. To investigate the connections between MTA and neuropsychological measures, a correlation analysis was performed.

Results

AD patients exhibited notably reduced MMSE, MoCA, and GDS scores, as well as an increased MTA total scores, time spent on TMT-A, and TMT-B compared to LLD patients (p < 0.05). TMT-A and TMT-B both exhibited excellent discriminatory power between AD and LLD, achieving area under curve (AUC) values of 92.2 and 94.2%, respectively. In AD patients, there was a negative correlation between MMSE and MoCA scores and MTA scores, while in LLD patients, there was a positive correlation between time spent on TMT-A and GDS scores and MTA scores.

Conclusion

AD patients experience more severe EFD and MTA than LLD patients. The differential diagnosis of AD and LLD can be aided by the useful tool known as TMT. It is important to acknowledge that TMT is capable of capturing only a fraction of the executive function, thus necessitating a cautious interpretation of research findings.

White matter hyperintensities and smaller cortical thickness are associated with neuropsychiatric symptoms in neurodegenerative and cerebrovascular diseases

BACKGROUND

Neuropsychiatric symptoms (NPS) are a core feature of most neurodegenerative and cerebrovascular diseases. White matter hyperintensities and brain atrophy have been implicated in NPS. We aimed to investigate the relative contribution of white matter hyperintensities and cortical thickness to NPS in participants across neurodegenerative and cerebrovascular diseases.

METHODS

Five hundred thirteen participants with one of these conditions, i.e. Alzheimer's Disease/Mild Cognitive Impairment, Amyotrophic Lateral Sclerosis, Frontotemporal Dementia, Parkinson's Disease, or Cerebrovascular Disease, were included in the study. NPS were assessed using the Neuropsychiatric Inventory - Questionnaire and grouped into hyperactivity, psychotic, affective, and apathy subsyndromes. White matter hyperintensities were quantified using a semi-automatic segmentation technique and FreeSurfer cortical thickness was used to measure regional grey matter loss.

RESULTS

Although NPS were frequent across the five disease groups, participants with frontotemporal dementia had the highest frequency of hyperactivity, apathy, and affective subsyndromes compared to other groups, whilst psychotic subsyndrome was high in both frontotemporal dementia and Parkinson's disease. Results from univariate and multivariate results showed that various predictors were associated with neuropsychiatric subsyndromes, especially cortical thickness in the inferior frontal, cingulate, and insula regions, sex(female), global cognition, and basal ganglia-thalamus white matter hyperintensities.

CONCLUSIONS

In participants with neurodegenerative and cerebrovascular diseases, our results suggest that smaller cortical thickness and white matter hyperintensity burden in several cortical-subcortical structures may contribute to the development of NPS. Further studies investigating the mechanisms that determine the progression of NPS in various neurodegenerative and cerebrovascular diseases are needed.

The heterogeneity of late-life depression and its pathobiology: a brain network dysfunction disorder

Depression is frequent in older individuals and is often associated with cognitive impairment and increasing risk of subsequent dementia. Late-life depression (LLD) has a negative impact on quality of life, yet the underlying pathobiology is still poorly understood. It is characterized by considerable heterogeneity in clinical manifestation, genetics, brain morphology, and function. Although its diagnosis is based on standard criteria, due to overlap with other age-related pathologies, the relationship between depression and dementia and the relevant structural and functional cerebral lesions are still controversial. LLD has been related to a variety of pathogenic mechanisms associated with the underlying age-related neurodegenerative and cerebrovascular processes. In addition to biochemical abnormalities, involving serotonergic and GABAergic systems, widespread disturbances of cortico-limbic, cortico-subcortical, and other essential brain networks, with disruption in the topological organization of mood- and cognition-related or other global connections are involved. Most recent lesion mapping has identified an altered network architecture with "depressive circuits" and "resilience tracts", thus confirming that depression is a brain network dysfunction disorder. Further pathogenic mechanisms including neuroinflammation, neuroimmune dysregulation, oxidative stress, neurotrophic and other pathogenic factors, such as β-amyloid (and tau) deposition are in discussion. Antidepressant therapies induce various changes in brain structure and function. Better insights into the complex pathobiology of LLD and new biomarkers will allow earlier and better diagnosis of this frequent and disabling psychopathological disorder, and further elucidation of its complex pathobiological basis is warranted in order to provide better prevention and treatment of depression in older individuals.

The course of depressive symptoms in Lewy body dementia and Alzheimer's disease

BACKGROUND

Depressive symptoms frequently affect patients with neurocognitive disorders. In cross-sectional studies, patients with Lewy body dementia (DLB) showed higher levels of depressive symptoms than those with Alzheimer's disease (AD). We here describe the 5 year course of depressive symptoms in patients with DLB and AD.

METHODS

Secondary analysis of a dementia study in Western Norway (DemVest) longitudinal cohort study.

SETTING

This multicenter study was conducted in memory clinics in Western Norway. 187 patients newly diagnosed with AD (n = 111) and DLB (n = 76) were followed up annually for 5 years. Depressive symptoms were assessed using the Montgomery Åsberg Depression Rating Scale (MADRS). MADRS subclusters dysphoria, retardation, vegetative, anhedonia were analyzed. The impact of proximity of death and the role of risk factors for depression and dementia on the course of depressive symptoms were evaluated.

RESULTS

We observed continuously increasing mean levels of depressive symptoms in DLB, while patients with AD showed a delayed increase at later follow-up visits. Increase in MADRS total score was mainly driven by increases in the anhedonia and retardation subclusters. Proximity to death was associated with an increase in depressive symptoms in DLB, while it tended to decrease in AD. Previous smoking and hearing loss were associated with higher MADRS scores during follow-up in the total sample.

LIMITATIONS

Yearly assessment of depressive symptoms might be too infrequent.

CONCLUSION

Depressive symptom load was consistently higher in DLB compared to AD during five years after diagnosis, but tended to become more similar at later stages.

Neuropsychiatric Symptoms of Alzheimer's Disease: An Anatomic-Genetic Framework for Treatment Development

BACKGROUND

Despite the burden on patients and caregivers, there are no approved therapies for the neuropsychiatric symptoms of Alzheimer's disease (NPS-AD). This is likely due to an incomplete understanding of the underlying mechanisms.

OBJECTIVE

To review the neurobiological mechanisms of NPS-AD, including depression, psychosis, and agitation.

METHODS

Understanding that genetic encoding gives rise to the function of neural circuits specific to behavior, we review the genetics and neuroimaging literature to better understand the biological underpinnings of depression, psychosis, and agitation.

RESULTS

We found that mechanisms involving monoaminergic biosynthesis and function are likely key elements of NPS-AD and while current treatment approaches are in line with this, the lack of effectiveness may be due to contributions from additional mechanisms including neurodegenerative, vascular, inflammatory, and immunologic pathways.

CONCLUSION

Within an anatomic-genetic framework, development of novel effective biological targets may engage targets within these pathways but will require a better understanding of the heterogeneity in NPS-AD.

Depressive symptoms due to stroke are strongly predicted by the volume and location of the cerebral infarction, white matter hyperintensities, hypertension, and age: A precision nomothetic psychiatry analysis

OBJECTIVES

To delineate the effects of white matter hyperintensities (WMHs) as measured by Fluid-attenuated inversion recovery (FLAIR) and infarction volume as measured by Diffusion-weighted imaging (DWI) on post-stroke depression symptoms.

METHODS

Baseline National Institutes of Health Stroke Score (NIHSS) and Modified Rankin Scale (mRS) scores, and FLAIR and DWI MRIs to assess WMHs and acute infarct volumes, respectively, were assessed in 47 patients (≥55 years) with acute ischemic stroke and 17 normal controls. The Montgomery-Åsberg Depression Rating Scale (MDRS) was assessed three months after the stroke.

RESULTS

The MADRS score was significantly increased in stroke patients as compared with normal controls. The MADRS scale is not unidimensional and cannot be used as an accurate indicator of depression severity in stroke patients. Three months after stroke, key depressive (sadness and inability to feel) and concentration-tension symptoms, and lassitude are significantly predicted by the infarct volume. Right side infarction strongly predicts key depressive symptoms and left side infarction strongly predicts concentration-tension and lassitude scores. Total WMHs significantly predict key depressive and concentration-tension symptoms, and lassitude, with these effects being mediated by right and left DWI stroke volumes and associated disabilities.

CONCLUSIONS

Interactions between age, hypertension, a chronic atherosclerotic process, and acute stroke account for the onset of key depressive symptoms three months after the acute infarct. Chronic and acute neuro-immune and neuro-oxidative stress pathways associated with the formation of WMHs and acute stroke may explain the incidence of post-stroke key depressive and concentration-tension symptoms, and lassitude.

Brain Morphometric Correlates of Depressive Symptoms among Patients with and without Dementia

Introduction

Findings regarding brain morphometry among patients with dementia and concomitant depressive symptoms have been inconsistent. Thus, the aim of the present study was to test the hypothesis that dementia and concomitant depressive symptoms are associated with structural brain changes in the temporal lobe measured with structural magnetic resonance imaging (MRI).

Methods

A sample of 492 patients from Norwegian memory clinics (n = 363) and Old Age Psychiatry services (n = 129) was studied. The assessment included the Cornell Scale for Depression in Dementia (CSDD), Instrumental Activities of Daily Living Scale, Mini Mental State Examination, and MRI of the brain, processed with FreeSurfer to derive ROI measures of cortical thickness, volume, and area using the Desikan-Killiany parcellation, as well as subcortical volumes. Dementia was diagnosed according to ICD-10 research criteria. Correlates of brain morphometry using multiple linear regression were examined.

Results

Higher scores on the CSDD were associated with larger cortical volume (β = 0.125; p value = 0.003) and area of the left isthmus of the cingulate gyrus (β = 0.151; p value = <0.001) across all patients. Inclusion of an interaction term (dementia × CSDD) revealed a smaller area in the left temporal pole (β = −0.345; p value = 0.001) and right-transverse temporal cortex (β = −0.321; p value = 0.001) in patients with dementia and depressive symptoms.

Discussion/Conclusion

We confirm the previous findings of structural brain changes in temporal regions among patients with dementia and concomitant depressive symptoms. This may contribute to a better understanding of the mechanisms underlying depression in dementia. To the best of our knowledge, this is the largest study conducted on this topic to date.

Investigating the contribution of white matter hyperintensities and cortical thickness to empathy in neurodegenerative and cerebrovascular diseases

Change in empathy is an increasingly recognised symptom of neurodegenerative diseases and contributes to caregiver burden and patient distress. Empathy impairment has been associated with brain atrophy but its relationship to white matter hyperintensities (WMH) is unknown. We aimed to investigate the relationships amongst WMH, brain atrophy, and empathy deficits in neurodegenerative and cerebrovascular diseases. Five hundred thirteen participants with Alzheimer's disease/mild cognitive impairment, amyotrophic lateral sclerosis, frontotemporal dementia (FTD), Parkinson's disease, or cerebrovascular disease (CVD) were included. Empathy was assessed using the Interpersonal Reactivity Index. WMH were measured using a semi-automatic segmentation and FreeSurfer was used to measure cortical thickness. A heterogeneous pattern of cortical thinning was found between groups, with FTD showing thinning in frontotemporal regions and CVD in left superior parietal, left insula, and left postcentral. Results from both univariate and multivariate analyses revealed that several variables were associated with empathy, particularly cortical thickness in the fronto-insulo-temporal and cingulate regions, sex (female), global cognition, and right parietal and occipital WMH. Our results suggest that cortical atrophy and WMH may be associated with empathy deficits in neurodegenerative and cerebrovascular diseases. Future work should consider investigating the longitudinal effects of WMH and atrophy on empathy deficits in neurodegenerative and cerebrovascular diseases.

Strategic Infarct Locations for Poststroke Depressive Symptoms: A Lesion- and Disconnection-Symptom Mapping Study

BACKGROUND

Depression is the most common neuropsychiatric complication after stroke. Infarct location is associated with poststroke depressive symptoms (PSDS), but it remains debated which brain structures are critically involved. We performed a large-scale lesion-symptom mapping study to identify infarct locations and white matter disconnections associated with PSDS.

METHODS

We included 553 patients (mean [SD] age = 69 [11] years, 42% female) with acute ischemic stroke. PSDS were measured using the 30-item Geriatric Depression Scale. Multivariable support vector regression (SVR)-based analyses were performed both at the level of individual voxels (voxel-based lesion-symptom mapping) and at predefined regions of interest to relate infarct location to PSDS. We externally validated our findings in an independent stroke cohort (N = 459). Finally, disconnectome-based analyses were performed using SVR voxel-based lesion-symptom mapping, in which white matter fibers disconnected by the infarct were analyzed instead of the infarct itself.

RESULTS

Infarcts in the right amygdala, right hippocampus, and right pallidum were consistently associated with PSDS (permutation-based p < .05) in SVR voxel-based lesion-symptom mapping and SVR region-of-interest analyses. External validation confirmed the association between infarcts in the right amygdala and pallidum, but not the right hippocampus, and PSDS. Disconnectome-based analyses revealed that disconnections in the right parahippocampal white matter, right thalamus and pallidum, and right anterior thalamic radiation were significantly associated (permutation-based p < .05) with PSDS.

CONCLUSIONS

Infarcts in the right amygdala and pallidum and disconnections of right limbic and frontal cortico-basal ganglia-thalamic circuits are associated with PSDS. Our findings provide a comprehensive and integrative picture of strategic infarct locations for PSDS and shed new light on pathophysiological mechanisms of depression after stroke.

The Longitudinal Assessment of Neuropsychiatric Symptoms in Mild Cognitive Impairment and Alzheimer's Disease and Their Association With White Matter Hyperintensities in the National Alzheimer's Coordinating Center's Uniform Data Set

BACKGROUND

Neuropsychiatric symptoms (NPSs) are common in Alzheimer's disease (AD). NPSs contribute to patients' distress, caregiver burden, and institutionalization. White matter hyperintensities (WMHs) appear on magnetic resonance imaging, usually indicative of cerebrovascular disease. WMHs have been associated with certain NPSs. We aimed to assess the relationship between WMH and NPS severity in mild cognitive impairment (MCI) due to AD (MCI-AD) and in AD and to assess the ability of WMHs to predict NPS progression. Data were obtained from the National Alzheimer's Coordinating Center.

METHODS

A total of 252 participants (114 with MCI-AD and 138 with AD) were used in this study. Baseline WMHs were quantified using an automated segmentation technique. NPSs were measured using the Neuropsychiatric Inventory. Mixed-effect models and correlations were used to determine the relationship between WMHs and NPSs.

RESULTS

Longitudinal mixed-effect models revealed a significant relationship between increase in Neuropsychiatric Inventory total scores and baseline WMHs (p = .014). There was a significant relationship between baseline WMHs and an increase in delusions (p = .023), hallucinations (p = .040), agitation (p = .093), depression (p = .017), and irritability (p = .002). Correlation plot analysis showed that baseline whole-brain WMHs predicted change in future Neuropsychiatric Inventory total scores (r = .169, p = .008) and predicted change in future agitation severity scores (r = .165, p = .009). WMHs in the temporal lobes (r = .169, p = .008) and frontal lobes (r = .153, p = .016) contributed most to this change.

CONCLUSIONS

Depression, irritability, and agitation are common NPSs and very distressful to patients and caregivers. Our findings of increased NPS severity over time in MCI-AD and AD with increased WMHs have important implications for treatment, arguing for aggressive treatment of vascular risk factors in patients with MCI-AD or AD.

White matter hyperintensities and neuropsychiatric symptoms in mild cognitive impairment and Alzheimer's disease

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White matter hyperintensities play a larger role than grey matter atrophy in neuropsychiatric symptoms in AD/MCI.

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Greater white matter hyperintensities are related to lower grey matter volumes.

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Frontotemporal atrophy implicated in neuropsychiatric symptoms.

Neuropsychiatric symptoms (NPS), such as apathy, irritability and depression, are frequently encountered in patients with Alzheimer’s disease (AD). Focal grey matter atrophy has been linked to NPS development. Cerebrovascular disease is common among AD patients and can be detected on MRI as white matter hyperintensities (WMH). In this longitudinal study, the relative contribution of WMH burden and GM atrophy to NPS was evaluated in a cohort of mild cognitive impairment (MCI), AD and normal controls. This study included 121 AD, 315 MCI and 225 normal control subjects from the Alzheimer’s Disease Neuroimaging Initiative. NPS were assessed using the Neuropsychiatric Inventory and grouped into hyperactivity, psychosis, affective and apathy subsyndromes. WMH were measured using an automatic segmentation technique and mean deformation-based morphometry (DBM) was used to measure atrophy of grey matter regions. Linear mixed-effects models found focal grey matter atrophy and WMH volume both contributed significantly to NPS subsyndromes in MCI and AD subjects, however, WMH burden played a greater role. This study could provide a better understanding of the pathophysiology of NPS in AD and support the monitoring and control of vascular risk factors.

Mechanisms Linking White Matter Lesions, Tract Integrity, and Depression in Alzheimer Disease

OBJECTIVE

Late-life depression involves the disconnection of white matter tracts that regulate mood. A pathogenic link between poor tract integrity and depressive symptoms is believed to be white matter lesions (WML), however the mechanisms linking tract integrity, WML, and depression remains unexplored. The authors sought to identify whether the association between reduced tract integrity and depressive symptoms is mediated by WML in patients with Alzheimer disease (AD), and whether individual characteristics moderate this effect.

METHODS

This was a cross-sectional study in a tertiary memory clinic. A total of 91 patients with mild AD and 79 healthy elderly, comparable in depressive symptoms, white matter hyperintensities (WMH) volume, cardiovascular risk, age, and sex were chosen. Tract integrity was assessed using diffusion tensor imaging, WML were indexed as WMH, measured using fluid-attenuation inversion recovery imaging, and depressive symptoms were measured with the informant-based Geriatric Depression Scale.

RESULTS

In patients with mild AD, reduced tract integrity in right hemispheric cortical-subcortical tracts and the genu of the corpus callosum was moderately associated with depressive symptoms. This association was fully mediated by WML. Moderation analysis indicated that old age strengthened the association between all tracts and depressive symptoms, as mediated by WML. In cognitively healthy elderly, neither tracts nor WML were related to depressive symptoms.

CONCLUSION

Reduced tract integrity may be important but not sufficient for the manifestation of depressive symptoms in mild AD. Instead, WML may drive the pathogenic link between reduced tract integrity and depressive symptoms.

Impact of white matter hyperintensity location on depressive symptoms in memory-clinic patients: a lesion–symptom mapping study

BACKGROUND

We investigated the association between white matter hyperintensity location and depressive symptoms in a memoryclinic population using lesion–symptom mapping.

METHODS

We included 680 patients with vascular brain injury from the TRACE-VCI cohort (mean age ± standard deviation: 67 ± 8 years; 52% female): 168 patients with subjective cognitive decline, 164 with mild cognitive impairment and 348 with dementia. We assessed depressive symptoms using the Geriatric Depression Scale. We applied assumptionfree voxel-based lesion–symptom mapping, adjusted for age, sex, total white matter hyperintensity volume and multiple testing. Next, we applied exploratory region-of-interest linear regression analyses of major white matter tracts, with additional adjustment for diagnosis.

RESULTS

Voxel-based lesion–symptom mapping identified voxel clusters related to the Geriatric Depression Scale in the left corticospinal tract. Region-of-interest analyses showed no relation between white matter hyperintensity volume and the Geriatric Depression Scale, but revealed an interaction with diagnosis in the forceps minor, where larger regional white matter hyperintensity volume was associated with more depressive symptoms in subjective cognitive decline (β = 0.26, p < 0.05), but not in mild cognitive impairment or dementia.

LIMITATIONS

We observed a lack of convergence of findings between voxel-based lesion–symptom mapping and region-of-interest analyses, which may have been due to small effect sizes and limited lesion coverage despite the large sample size. This warrants replication of our findings and further investigation in other cohorts.

CONCLUSION

This lesion–symptom mapping study in depressive symptoms indicates the corticospinal tract and forceps minor as strategic tracts in which white matter hyperintensity is associated with depressive symptoms in memory-clinic patients with vascular brain injury. The impact of white matter hyperintensity on depressive symptoms is modest, but it appears to depend on the location of white matter hyperintensity and disease severity.

Effect of Vascular Risk Factors on the Progression of Mild Alzheimer's Disease and Lewy Body Dementia

BACKGROUND

Vascular risk factors (VRF) are associated with an increased risk of neurodegenerative disease.

OBJECTIVE

To examine the association between VRF and cognitive decline in patients with Alzheimer's disease (AD) and Lewy body dementia (LBD).

METHODS

We included consecutive referrals with mild AD or LBD to dementia clinics in western Norway from 2005 to 2013. The Mini-Mental Status Exam (MMSE) and Clinical Dementia Rating Scale Sum of Boxes (CDR-SB) were administered at baseline and then annually for up to five years. The VRF include diabetes mellitus, hypertension, hypercholesterolemia, overweight and smoking. Generalized Estimating Equations (GEE) were used to examine the potential association between VRF scores and the change in MMSE and CDR-SB scores, adjusting for age, sex, and the apolipoprotein ɛ4 allele (APOE4).

RESULTS

A total of 200 patients were included (113 AD, 87 LBD) (mean age 76 years, mean baseline MMSE 24.0, mean follow-up time 3.5 years). Smoking was the only VRF significantly associated with a more rapid cognitive decline, however only in the AD group. Being overweight at baseline was associated with a slower cognitive decline. Moreover, hypertension at baseline predicted a slower decline in MMSE scores. In the LBD group diabetes mellitus was found to be associated with a slower increase in CDR-SB scores.

CONCLUSION

With the exception of smoking, VRF at time of dementia diagnosis were not associated with a more rapid cognitive decline.

White Matter Lesions are Associated with Specific Depressive Symptom Trajectories among Incident Depression and Dementia Populations: Three-City Dijon MRI Study

OBJECTIVE

Evidence is mixed as to whether periventricular or deep white matter hyperintensities (WMHs) increase the risk for depressive symptoms, partly because of heterogeneity in depression measurement, short follow-up, and confounding by prodromal dementia. The study objective was to evaluate WMH volume in relation to discrete depressive symptoms over 10 years, stratifying by incident depression and dementia.

METHODS

In this prospective longitudinal cohort study of a representative population sample from Dijon, France, 1,440 participants aged 65-80 years (median age: 72 years; 59.5% women) without depression, dementia, or stroke at baseline were studied. Baseline T2-weighted images were obtained in a 1.5-T scanner to quantify WMHs (log cm³). Clinic visits were performed up to five times in a 10-year period to assess incident neurologic diseases and comorbidities. Depressive symptoms were measured with the Center for Epidemiologic Studies Depression Scale and converted to factor z scores, representing somatic symptoms, depressed affect, low positive affect, and interpersonal problems.

RESULTS

Periventricular WMH volume was uniquely associated with low positive affect among incident depression cases (β = 0.15; 95% confidence interval [CI]: 0.02-0.29; p = 0.026). Deep WMH volume was uniquely associated with depressed affect among incident dementia cases (β = 0.36; 95% CI: 0.05-0.68; p = 0.025). WMH volume (periventricular, deep, and total) was associated with interpersonal problems among persons who developed dementia with depression.

CONCLUSION

The findings highlight that regional WMH volumes and specific depressive symptoms have clinical and prognostic relevance to help differentiate between persons at risk for depression and dementia.

Trajectories of depressive symptoms and their relationship to the progression of dementia

BACKGROUND

The relationship between progression of Alzheimer's disease and depression and its underlying mechanisms has scarcely been studied.

METHODS

A sample of 282 outpatients with Alzheimer's disease (AD; 105 with amnestic AD and 177 with Alzheimer's dementia) from Norway were followed up for an average of two years. Assessment included Cornell Scale for Depression in Dementia and Clinical Dementia Rating Scale (CDR) at baseline and follow-up to examine the relationship between AD and depression. Additionally, MRI of the brain, CSF dementia biomarkers and APOE status were assessed at baseline. Progression of dementia was defined as the difference between CDR sum of boxes at follow-up and baseline (CDR-SB change). Trajectories of depressive symptoms on the Cornell Scale were identified using growth mixture modeling. Differences between the trajectories in regard to patients' characteristics were investigated.

RESULTS

Three distinct trajectories of depressive symptoms were identified: 231 (82.8%) of the patients had stable low-average scores on the Cornell Scale (Class 1); 11 (3.9%) had high and decreasing scores (Class 2); and 37 (13.3%) had moderate and increasing scores (Class 3). All classes had average probabilities over 80%, and confidence intervals were non-overlapping. The only significant characteristic associated with membership in class 3 was CDR-SB change.

LIMITATIONS

Not all patients screened for participation were included in the study, but the included and non-included patients did not differ significantly. Some patients with amnestic MCI might have been misdiagnosed.

CONCLUSION

A more rapid progression of dementia was found in a group of patients with increasing depressive symptoms.

Neuropsychiatric Symptoms in Alzheimer Disease, Vascular Dementia, and Mixed Dementia

BACKGROUND/AIMS

Neuropsychiatric symptoms (NPS) are common in Alzheimer disease (AD) and vascular dementia (VaD), and are distressful to patients and caregivers. NPS are likely related to the underlying pathology. Previous studies suggest that frontal lobe lesions and vascular changes such as white matter hyperintensities (WMH) have a significant association with specific NPS. The current study aimed to compare NPS in patients with AD, VaD, and mixed AD/VaD, and to evaluate the differences in the prevalence of NPS in relation to frontal WMH volume.

METHODS

In total, 180 patients with NPS and MRI data (92 probable AD, 51%; 34 probable VaD, 19%; and 54 probable mixed AD/VaD, 30%) were included in the study. Regression analyses were performed to determine the relationships between NPS prevalence and diagnosis, and between NPS and frontal WMH.

RESULTS

VaD patients had significantly more agitation (p < 0.05; 40 vs. 14%) and sleep disturbances (p < 0.05; 57 vs. 32%) than AD patients, and significantly more depression (p < 0.05; 48 vs. 20%) and aberrant motor behaviors (p < 0.05; 31 vs. 13%) than mixed AD/VaD patients. AD patients with delusions had significantly greater right frontal WMH volumes than those without (p < 0.05; delusions 1/0 = 314.8/112.6 mm3).

CONCLUSION

Differences in NPS prevalence are likely related to the underlying pathology and warrant further study as they have implications for treatment.

Regional Coherence Changes in Alzheimer's Disease Patients with Depressive Symptoms: A Resting-State Functional MRI Study

Alzheimer's disease (AD) is characterized by progressive cognitive decline along with neuropsychiatric symptoms including depression and psychosis. Depression is a common psychiatric disorder occurring in people across the lifespan. Accumulating evidence indicates that depression may be a prodrome and/or a "risk factor" for AD. However, whether AD and depression share a common pathophysiological pathway is still unclear. The aim of this study was to identify regional alterations in brain function associated with depressive symptoms in mild AD patients. Thirty-two mild AD patients were evaluated using the Neuropsychiatric Inventory and Hamilton Depression Rating Scale, and were divided into two groups: 15 AD patients with depressive symptoms (D-AD) and 17 non-depressed AD (nD-AD) patients. Using the approach of regional homogeneity (ReHo), we characterized resting-state regional brain activity in D-AD and nD-AD patients. Compared with nD-AD patients, D-AD patients showed decreased ReHo in the right precentral gyrus, right superior frontal gyrus, right middle frontal gyrus, and right inferior frontal cortex. Our findings show regional brain activity alterations in D-AD patients. Thus, D-AD pathogenesis may be attributed to abnormal neural activity in multiple brain regions.

Abnormal degree centrality in Alzheimer's disease patients with depression: A resting-state functional magnetic resonance imaging study

Depression is common in Alzheimer's disease (AD) and occurs in AD patients with a prevalence of up to 40%. It reduces cognitive function and increases the burden on caregivers. Currently, there are very few medications that are useful for treating depression in AD patients. Therefore, understanding the brain abnormalities in AD patients with depression (D-AD) is crucial for developing effective interventions. The aim of this study was to investigate the intrinsic dysconnectivity pattern of whole-brain functional networks at the voxel level in D-AD patients based on degree centrality (DC) as measured by resting-state functional magnetic resonance imaging (R-fMRI). Our study included 32 AD patients. All patients were evaluated using the Neuropsychiatric Inventory and Hamilton Depression Rating Scale and further divided into two groups: 15 D-AD patients and 17 non-depressed AD (nD-AD) patients. R-fMRI datasets were acquired from these D-AD and nD-AD patients. First, we performed a DC analysis to identify voxels that showed altered whole brain functional connectivity (FC) with other voxels. We then further investigated FC using the abnormal DC regions to examine in more detail the connectivity patterns of the identified DC changes. D-AD patients had lower DC values in the right middle frontal, precentral, and postcentral gyrus than nD-AD patients. Seed-based analysis revealed decreased connectivity between the precentral and postcentral gyrus to the supplementary motor area and middle cingulum. FC also decreased in the right middle frontal, precentral, and postcentral gyrus. Thus, AD patients with depression fit a 'network dysfunction model' distinct from major depressive disorder and AD.

Impact of White Matter Lesions on Depression in the Patients with Alzheimer's Disease

OBJECTIVE

Comorbid depression is common in patients with Alzheimer's disease (AD). An increase in white matter lesions (WMLs) has been associated with depression in both elderly individuals with normal cognition and patients with Alzheimer's disease. We investigated whether the severity and location of WMLs influence the association between WMLs and comorbid depression in AD.

METHODS

We enrolled 93 AD patients from Seoul National University Bundang Hospital. We administered both the Mini International Neuropsychiatric Inventory (MINI) and the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease Assessment Packet (CERAD-K) clinical and neuropsychological battery. Subjects also underwent brain magnetic resonance imaging (MRI). We diagnosed AD according to the criteria of the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association. We diagnosed depressive disorders according to the DSM-IV diagnostic criteria, and evaluated the severity of depressive symptoms using the Korean version of the Geriatric Depression Scale (GDS-K). We quantified the WML volumes from the brain MRI using a fully automated segmentation algorithm.

RESULTS

The log of the WML volume in the frontal lobe was significantly associated with depressive disorders (odds ratio=1.905, 95% CI=1.027-3.533, p=0.041), but not with the severity of depressive symptoms as measured by the GDS-K.

CONCLUSION

The WML volume in the frontal lobe conferred a risk of comorbid depressive disorders in AD, which implies that comorbid depression in AD may be attributed to vascular causes.

Classifying dementia using local binary patterns from different regions in magnetic resonance images

Dementia is an evolving challenge in society, and no disease-modifying treatment exists. Diagnosis can be demanding and MR imaging may aid as a noninvasive method to increase prediction accuracy. We explored the use of 2D local binary pattern (LBP) extracted from FLAIR and T1 MR images of the brain combined with a Random Forest classifier in an attempt to discern patients with Alzheimer's disease (AD), Lewy body dementia (LBD), and normal controls (NC). Analysis was conducted in areas with white matter lesions (WML) and all of white matter (WM). Results from 10-fold nested cross validation are reported as mean accuracy, precision, and recall with standard deviation in brackets. The best result we achieved was in the two-class problem NC versus AD + LBD with total accuracy of 0.98 (0.04). In the three-class problem AD versus LBD versus NC and the two-class problem AD versus LBD, we achieved 0.87 (0.08) and 0.74 (0.16), respectively. The performance using 3DT1 images was notably better than when using FLAIR images. The results from the WM region gave similar results as in the WML region. Our study demonstrates that LBP texture analysis in brain MR images can be successfully used for computer based dementia diagnosis.

Medial temporal lobe atrophy and depressive symptoms in elderly patients with and without Alzheimer disease

OBJECTIVE

To determine whether depressive symptoms are associated with medial temporal lobe atrophy in older people with and without Alzheimer disease (AD).

METHOD

A total of 368 memory clinic patients with AD, mild cognitive impairment, and subjective cognitive impairment (SCI) were included. Depressive symptoms were defined as a score of 8 or higher on Cornell Scale for Depression in Dementia or use of antidepressant medications. Magnetic resonance imaging and computer tomography scans were rated for medial temporal lobe atrophy (MTA), using the Scheltens scale. For a subsample (n = 57 patients), hippocampal volume was manually traced.

RESULTS

Based on visual assessment, AD patients with depressive symptoms had less atrophy of the right medial temporal lobe (odds ratio [OR] for having MTA: 0.39; 95% confidence interval [CI] 0.16-0.99) and decreased scores on Scheltens scale for the left medial temporal lobe (OR: 0.43, 95% CI 0.19-0.96) in comparison to AD patients without depressive symptoms. In the subgroup where manual tracing was used to measure hippocampal volume, people with SCI experiencing depressive symptoms had smaller right (mean difference: 0.28 cm(3); P = .005) and left (mean difference 0.32 cm(3); P = .002) hippocampal volumes compared to people with SCI who did not have depressive symptoms.

CONCLUSION

Hippocampal atrophy was more pronounced among patients having SCI with depressive symptoms, while the medial temporal lobe was less atrophic in patients having AD with depressive symptoms than those without depressive symptoms. These findings suggest that different mechanisms underlie depression in older people with and without AD and may explain some of the inconsistent observations in previous studies.

Persistence and Prognostic Implications of Orthostatic Hypotension in Older Individuals with Mild-to-Moderate Dementia

AIM

To study the course and prognostic implications of orthostatic hypotension (OH) in older individuals with mild-to-moderate dementia.

METHODS

Referrals to outpatient clinics specialising in old age psychiatry and geriatric medicine in the counties of Rogaland and Hordaland in western Norway with a first-time diagnosis of mild dementia were consecutively asked for inclusion. A total of 211 participants underwent a comprehensive baseline assessment with annual follow-ups. Patients with OH at both baseline and the 1-year follow-up were classified as having persistent OH. Outcome measures were the Mini-Mental State Examination (MMSE), the Clinical Dementia Rating sum of boxes (CDR-SB), and time to death.

RESULTS

From baseline to the 4-year follow-up, 30-45% of the participants had OH at each follow-up. In multivariable analysis, persistent OH was not significantly associated with either the longitudinal course of MMSE or CDR-SB scores or survival.

CONCLUSIONS

OH was moderately prevalent over 4 years in older individuals with mild dementia, and persistent OH did not predict either cognitive or functional decline or survival.

Cortical changes associated with depression and antidepressant use in Alzheimer and Lewy body dementia: an MRI surface-based morphometric study

CONTEXT

Depression is common in dementia, especially in the early stages, with important clinical implications, but the etiology is unknown and most likely heterogeneous. Antidepressant use in the elderly without dementia has previously been shown to be associated with high risks of adverse events and with structural brain alterations.

OBJECTIVE

To investigate cortical changes associated with depression and antidepressant use in patients with mild Alzheimer's disease (AD) and Lewy body dementia (LBD).

METHODS

74 subjects with mild AD and LBD from geriatric and psychiatry outpatient clinics in Western Norway were included. The Montgomery-Asberg Depression Rating Scale (MADRS) was used to assess depression. Automatic preprocessing using Freesurfer included steps for white and grey matter surface reconstruction. The resulting cortical thickness was analyzed using linear modeling.

RESULTS

Clusters of depression-associated thinning were found in prefrontal and temporal areas. Treatment-associated thinning was observed in the parahippocampal region and was significant even after correction for age, sex, AD/LBD diagnosis, and MADRS scores.

CONCLUSION

Depression in mild AD and LBD is associated with cortical thinning in prefrontal and temporal areas. The findings suggest that depressive symptoms in mild dementia could develop due to neurodegeneration in the same neural circuits that are critical for depression across different brain disorders. Antidepressant use in patients with mild AD and LBD is associated with parahippocampal thinning. Taken together with low efficacy of antidepressants in cognitively impaired patients and high risks of adverse events, our results suggest a need to re-evaluate the treatment approaches for depression and the role of antidepressants in patients with dementia.

Prevalence and clinical implication of microbleeds in dementia with lewy bodies in comparison with microbleeds in Alzheimer's disease

Background

Cerebral microbleeds (MBs) have been well investigated in Alzheimer's disease (AD), but not very extensively in non-AD dementias or in dementia with Lewy bodies (DLB).

Aims

To elucidate the clinical significance of MBs in DLB.

Methods

We compared the prevalence, locations and risk factors for MBs in 59 DLB and 81 AD patients. We visually counted MBs in each of the cortical and subjacent areas (frontal, temporal, parietal and occipital), the basal ganglia and the thalamus, and the brainstem and the cerebellar hemispheres on 1.5-tesla T2*-weighted gradient-recalled-echo MRI images. White matter lesions were semiquantified in fluid-attenuated inversion recovery images according to the Fazekas rating scale.

Results

While the prevalence of MBs was comparable, MBs tended to be more abundant in DLB than in AD in all brain areas with the exception of the occipital lobes. The number of MBs was positively associated with the severity of white matter lesions but not with other vascular risk factors in either AD or DLB. The presence of MBs could be associated with cognitive impairment at onset. MB-positive DLB patients showed less impairment on ¹²³I-metaiodobenzylguanidine myocardial scintigraphy (MIBG scintigraphy) images, supporting the notion of an inverse relationship between vascular lesions and Lewy body pathology.

Conclusion

It was suggested that an intricate association between Lewy body pathology, AD-type pathologies and vascular lesions seems to be related to the initial symptoms and results of MIBG scintigraphy in DLB.

Not all depression is created equal: sex interacts with disease to precipitate depression

Depression is a common mental disorder that co-occurs in other neurological and somatic diseases. Further, sex differences exist in the prevalence rates of many of these diseases, as well as within non-disease associated depression. In this review, the case is made for needing a better recognition of the source of the symptoms of depression with respect to the sex of the individual; in that, some disease states, which includes the neuroendocrine and immune reactions to the underlying pathophysiology of the disease, may initiate depressive symptoms more often in one sex over the other. The diseases specifically addressed to make this argument are: epilepsy, Alzheimer’s disease, cancer, and cardiovascular disease. For each of these conditions, a review of the following are presented: prevalence rates of the conditions within each sex, prevalence rates of depressive symptoms within the conditions, identified relationships to gonadal hormones, and possible interactions between gonadal hormones, adrenal hormones, and immune signaling. Conclusions are drawn suggesting that an evaluation of the root causes for depressive symptoms in patients with these conditions is necessary, as the underlying mechanisms for eliciting the depressive symptoms may be qualitatively different across the four diseases discussed. This review attempts to identify and understand the mechanisms of depression associated with these diseases, in the context of the known sex differences in the disease prevalence and its age of onset. Hence, more extensive, sex-specific model systems are warranted that utilize these disease states to elicit depressive symptoms in order to create more focused, efficient, and sex-specific treatments for patients suffering from these diseases and concurrent depressive symptoms.

Organic bases of late-life depression: a critical update

Late-life depression (LLD) is frequently associated with cognitive impairment and increases the risk of subsequent dementia. Cerebrovascular disease, deep white matter lesions, Alzheimer disease (AD) and dementia with Lewy bodies (DLB) have all been hypothesized to contribute to this increased risk, and a host of studies have looked at the interplay between cerebrovascular disease and LLD. This has resulted in new concepts of LLD, such as "vascular depression", but despite multiple magnetic resonance imaging (MRI) studies in this field, the relationship between structural changes in human brain and LLD is still controversial. While pathological findings of suicide in some elderly persons revealed multiple lacunes, small vessel cerebrovascular disease, AD-related lesions or multiple neurodegenerative pathologies, recent autopsy data challenged the role of subcortical lacunes and white matter lesions as major morphological substrates of depressive symptoms as well as poorer executive function and memory. Several neuropathological studies, including a personal clinico-pathological study in a small cohort of elderly persons with LLD and age-matched controls confirmed that lacunes, periventricular and deep white matter demyelination as well as AD-related lesions are usually unrelated to the occurrence of LLD. In the same line, neuropathological data show that early-onset depression is not associated with an acceleration of age-related neurodegenerative changes. Very recent data on the critical role of glia-modulating neuronal dysfunction and degeneration in depression are discussed.

Relationship between orthostatic hypotension and white matter hyperintensity load in older patients with mild dementia

Background/Objectives

White matter hyperintensities (WMH) in magnetic resonance imaging (MRI) scans of the brain, and orthostatic hypotension (OH) are both common in older people. We tested the hypothesis that OH is associated with WMH.

Design

Cross-sectional study.

Setting

Secondary care outpatient clinics in geriatric medicine and old age psychiatry in western Norway.

Participants

160 older patients with mild dementia, diagnosed according to standardised criteria.

Measurements

OH was diagnosed according to the consensus definition, measuring blood pressure (BP) in the supine position and within 3 minutes in the standing position. MRI scans were performed according to a common protocol at three centres, and the volumes of WMH were quantified using an automated method (n = 82), followed by manual editing. WMH were also quantified using the visual Scheltens scale (n = 139). Multiple logistic regression analyses were applied, with highest vs. lowest WMH quartile as response.

Results

There were no significant correlations between WMH volumes and systolic or diastolic orthostatic BP drops, and no significant correlations between Scheltens scores of WMH and systolic or diastolic BP drops. In the multivariate analyses, only APOEε4 status remained a significant predictor for WMH using the automated method (p = 0.037, OR 0.075 (0.007–0.851)), whereas only age remained a significant predictor for WMH scores (p = 0.019, OR 1.119 (1.018–1.230)).

Conclusion

We found no association between OH and WMH load in a sample of older patients with mild dementia.

White matter hyperintensities in mild lewy body dementia

Background

The objective of this study was to explore the load of white matter hyperintensities (WMH) in patients with Lewy body dementia (LBD) and compare to Alzheimer's disease (AD) and normal controls (NC).

Methods

Diagnosis of LBD and AD was made according to consensus criteria and cognitive tests were administered. MRI scans for 77 (61 AD and 16 LBD) patients and 37 healthy elderly control subjects were available for analysis. We segmented WMH from FLAIR images using an automatic thresholding technique and calculated the volume of WMH in several regions of the brain, using non-parametric tests to compare groups. Multivariate regression was applied.

Results

There were no significant differences in WMH between AD and LBD. We found a significant correlation between total and frontal WMH and Mini-Mental State Examination (MMSE) and verbal fluency scores in the AD group, but not in the LBD group.

Conclusion

The WMH load in LBD was similar to that of AD. A correlation between WMH load and cognition was found in the AD group, but not in the LBD group, suggesting that vascular disease contributes to cognitive impairment in AD but not LBD.