Dementia with Lewy bodies: diagnosis and management

Insights into the management of Lewy body dementia: a scoping review

Lewy body dementia (LBD) is situated at the convergence of neurodegenerative disorders, posing an intricate and diverse clinical dilemma. The accumulation of abnormal protein in the brain, namely, the Lewy body causes disturbances in typical neural functioning, leading to a range of cognitive, motor, and mental symptoms that have a substantial influence on the overall well-being and quality of life of affected individuals. There is no definitive cure for the disease; however, several nonpharmacological and pharmacological modalities have been tried with questionable efficacies. The aim of this study is to figure out the role of different interventional strategies in the disease. Donepezil, rivastigmine, memantine, and galantamine were the commonly used drugs for LBD. Together with that, levodopa, antipsychotics, armodafinil, piracetam, and traditional medications like yokukansan were also used, when indicated. Talking about nonpharmacological measures, exercise, physical therapy, multicomponent therapy, occupational therapy, psychobehavioral modification, transcranial stimulation, and deep brain stimulation have been used with variable efficacies. Talking about recent advances in the treatment of LBD, various disease-modifying therapies like ambroxol, neflamapimod, irsenontrine, nilotinib, bosutinib, vodobatinib, clenbuterol, terazosin, elayta, fosgonimeton, and anle138b are emerging out. However, there drugs are still in the different phases of clinical trials and are not commonly used in clinical practice. With the different pharmacological and nonpharmacological modalities we have for treatment of LBD, all of them offer symptomatic relief only. Being a degenerative disease, definite cure of the disease can only be possible with regenerative measures.

Clinical Manifestations of Early-Onset Dementia With Lewy Bodies Compared With Late-Onset Dementia With Lewy Bodies and Early-Onset Alzheimer Disease

Importance

Early-onset dementia, presenting in individuals younger than 65 years, is a diagnosis with significant social and financial implications. The early-onset form of dementia with Lewy bodies (DLB) is poorly understood.

Objective

To investigate clinical features that distinguish early-onset DLB (onset and diagnosis at age <65 years) from late-onset DLB (onset at age ≥65 years) and from early-onset Alzheimer disease (AD) dementia.

Design, Setting, and Participants

This is a retrospective case-control study on patients with pathologically confirmed DLB or AD enrolled in the National Alzheimer's Coordinating Center database from January 2005 to July 2017. The National Alzheimer's Coordinating Center Uniform Data Set comprised deidentified data collected by Alzheimer disease centers in the United States. Of patients fulfilling criteria for all-cause dementia at enrollment (n = 1152), those who at post mortem received a pathological diagnosis of either AD (n = 848) or Lewy body disease (n = 218) were selected. Excluding 52 patients owing to missing data and 12 diagnosed with Parkinson disease dementia, remaining patients were classified by age of symptom onset into early-onset AD, early-onset DLB, and late-onset DLB subgroups. Data were analyzed from June to December 2018 and from November to December 2021.

Exposures

Demographics, cognitive, behavioral, and motor features recorded at first clinic visit and neuropathological characteristics at autopsy were analyzed by disease subgroup.

Main Outcomes and Measures

Concordance between initial etiologic diagnosis of dementia and final pathological diagnosis was assessed, as was time to death.

Results

A total of 542 individuals were categorized as having early-onset AD (n = 363; mean [SD] age, 53.0 [5.8] years; 208 [57.3%] male), early-onset DLB (n = 32; mean [SD] age, 57.9 [3.2] years; 23 [71.9%] male), and late-onset DLB (n = 147; mean [SD] age, 73.5 [5.5] years; 103 [70.1%] male). Early-onset DLB was clinically misdiagnosed in 16 individuals (50%). Features that predicted a diagnosis of early-onset DLB over early-onset AD included visual hallucinations (15 [46.9%] vs 42 [11.6%]), slowness (23 [71.9%] vs 95 [26.2%]), apathy (23 [71.9%] vs 189 [52.1%]), and motor deterioration that preceded cognitive and behavioral symptoms (7 [21.9%] vs 6 [1.7%]). Late-onset DLB had more amnestic features, but this was accounted for by a higher proportion of neocortical neuritic plaques and diffuse plaques (frequent in 79 [53.7%] vs 8 [25%]) than seen in early-onset DLB.

Conclusions and Relevance

This study found that early-onset DLB has clinical features that distinguish it from early-onset AD, whereas features of late-onset DLB are associated with a higher burden of AD copathology.

Genetic Architecture and Molecular, Imaging and Prodromic Markers in Dementia with Lewy Bodies: State of the Art, Opportunities and Challenges

Dementia with Lewy bodies (DLB) is one of the most common causes of dementia and belongs to the group of α-synucleinopathies. Due to its clinical overlap with other neurodegenerative disorders and its high clinical heterogeneity, the clinical differential diagnosis of DLB from other similar disorders is often difficult and it is frequently underdiagnosed. Moreover, its genetic etiology has been studied only recently due to the unavailability of large cohorts with a certain diagnosis and shows genetic heterogeneity with a rare contribution of pathogenic mutations and relatively common risk factors. The rapid increase in the reported cases of DLB highlights the need for an easy, efficient and accurate diagnosis of the disease in its initial stages in order to halt or delay the progression. The currently used diagnostic methods proposed by the International DLB consortium rely on a list of criteria that comprises both clinical observations and the use of biomarkers. Herein, we summarize the up-to-now reported knowledge on the genetic architecture of DLB and discuss the use of prodromal biomarkers as well as recent promising candidates from alternative body fluids and new imaging techniques.

Direct Medical Costs of Dementia With Lewy Bodies by Disease Complexity

OBJECTIVES

There is currently no accurate profile of the economic burden of dementia with Lewy bodies (DLB), particularly any examination of the direct medical costs of DLB by the number of affected clinical domains. Understanding how trends in the use of healthcare resources evolve as DLB progresses presents opportunities for the development of earlier and more appropriate interventions.

DESIGN

Retrospective study using claims data extracted from the IBM MarketScan Commercial and Medicare Supplemental database.

SETTING AND PARTICIPANTS

In total, 536 patients with DLB from the Commercial database and 5485 patients with DLB from the Medicare Supplemental database.

METHODS

Patients were grouped into disease complexity categories based on core clinical features (ie, fluctuating cognition, motor symptoms, visual hallucinations, and rapid eye movement sleep behavior disorder in addition to dementia) observed during the study period: dementia with no core features observed, dementia plus 1, 2, or ≥3 core features, respectively. Outcome measures included healthcare resource utilization and healthcare costs.

RESULTS

In both databases, total healthcare resource utilization and costs increased with number of core features. Compared with patients with no core features observed, patients in all other complexity categories had significantly higher mean medical visits and costs in both adjusted and unadjusted analyses. Fluctuating cognition was associated with the highest total costs, suggesting that this clinical feature in particular is associated with a considerable economic burden.

CONCLUSIONS AND IMPLICATIONS

Analyzing direct medical costs of DLB by disease complexity using claims data showed that a higher cost impact was associated with increasing number of clinical domains affected and with specific clinical domains, suggesting the need for both targeted and comprehensive interventions to improve the overall economic burden of DLB.

Immunotherapies in Huntington's disease and α-Synucleinopathies

Modulation of immune activation using immunotherapy has attracted considerable attention for many years as a potential therapeutic intervention for several inflammation-associated neurodegenerative diseases. However, the efficacy of single-target immunotherapy intervention has shown limited or no efficacy in alleviating disease burden and restoring functional capacity. Marked immune system activation and neuroinflammation are important features and prodromal signs in polyQ repeat disorders and α-synucleinopathies. This review describes the current status and future directions of immunotherapies in proteinopathy-induced neurodegeneration with emphasis on preclinical and clinical efficacies of several anti-inflammatory compounds and antibody-based therapies for the treatment of Huntington's disease and α-synucleinopathies. The review concludes with how disease modification and functional restoration could be achieved by using targeted multimodality therapy to target multiple factors.

Epidemiology and mental illness in old age

This is an overview of epidemiology relevant to mental health problems in old age. We start by reviewing some basic terminology: the definitions of prevalence and incidence; the difference between descriptive and analytical epidemiology; the differences between study designs, including cross-sectional, case–control and cohort studies. We then cover the main epidemiological features of the major psychiatric diseases that affect older people (dementia and its different types, depression, late-onset schizophrenia, bipolar affective disorder, delirium, anxiety-related disorders, eating disorders, alcohol and substance misuse, personality disorders) and suicide.

We end with some descriptive statistics regarding quality of life in older people.

Psychiatric side-effects of medications: recent developments

Medications often induce neuropsychiatric side-effects. This article reviews psychiatric side-effects that are well known and describes those induced by recently developed medications. Therapeutic innovations have been prominent in the treatment of HIV infection, Parkinson's disease and epilepsy and therefore psychiatric side-effects caused by these agents are described in more detail.

Causes, Consequences and Public Health Implications of Low B-Vitamin Status in Ageing

The potential protective roles of folate and the metabolically related B-vitamins (vitamins B12, B6 and riboflavin) in diseases of ageing are of increasing research interest. The most common cause of folate and riboflavin deficiencies in older people is low dietary intake, whereas low B12 status is primarily associated with food-bound malabsorption, while sub-optimal vitamin B6 status is attributed to increased requirements in ageing. Observational evidence links low status of folate and the related B-vitamins (and/or elevated concentrations of homocysteine) with a higher risk of degenerative diseases including cardiovascular disease (CVD), cognitive dysfunction and osteoporosis. Deficient or low status of these B-vitamins alone or in combination with genetic polymorphisms, including the common MTHFR 677 C → T polymorphism, could contribute to greater disease risk in ageing by causing perturbations in one carbon metabolism. Moreover, interventions with the relevant B-vitamins to optimise status may have beneficial effects in preventing degenerative diseases. The precise mechanisms are unknown but many have been proposed involving the role of folate and the related B-vitamins as co-factors for one-carbon transfer reactions, which are fundamental for DNA and RNA biosynthesis and the maintenance of methylation reactions. This review will examine the evidence linking folate and related B-vitamins with health and disease in ageing, associated mechanisms and public health implications.

Comparing Cognitive Profiles of Licensed Drivers with Mild Alzheimer's Disease and Mild Dementia with Lewy Bodies

Purpose. Alzheimer's disease (AD) and dementia with Lewy Bodies (DLB) constitute two of the most common forms of dementia in North America. Driving is a primary means of mobility among older adults and the risk of dementia increases with advanced age. The purpose of this paper is to describe the cognitive profile of licensed drivers with mild AD and mild DLB. Method. Licensed drivers with mild AD, mild DLB, and healthy controls completed neuropsychological tests measuring general cognition, attention, visuospatial/perception, language, and cognitive fluctuations. Results. The results showed differences between healthy controls and demented participants on almost all neuropsychological measures. Participants with early DLB were found to perform significantly worse on some measures of attention and visuospatial functioning in comparison with early AD. Discussion. Future research should examine the relationship between neuropsychological measures and driving outcomes among individuals with mild AD and mild DLB.

Driving Competence in Mild Dementia with Lewy Bodies: In Search of Cognitive Predictors Using Driving Simulation

Driving is a multifactorial behaviour drawing on multiple cognitive, sensory, and physical systems. Dementia is a progressive and degenerative neurological condition that impacts the cognitive processes necessary for safe driving. While a number of studies have examined driving among individuals with Alzheimer's disease, less is known about the impact of Dementia with Lewy Bodies (DLB) on driving safety. The present study compared simulated driving performance of 15 older drivers with mild DLB with that of 21 neurologically healthy control drivers. DLB drivers showed poorer performance on all indicators of simulated driving including an increased number of collisions in the simulator and poorer composite indicators of overall driving performance. A measure of global cognitive function (i.e., the Mini Mental State Exam) was found to be related to the overall driving performance. In addition, measures of attention (i.e., Useful Field of View, UFOV) and space processing (Visual Object and Space Perception, VOSP, Test) correlated significantly with a rater's assessment of driving performance.

Genetic analysis implicates APOE, SNCA and suggests lysosomal dysfunction in the etiology of dementia with Lewy bodies

Clinical and neuropathological similarities between dementia with Lewy bodies (DLB), Parkinson's and Alzheimer's diseases (PD and AD, respectively) suggest that these disorders may share etiology. To test this hypothesis, we have performed an association study of 54 genomic regions, previously implicated in PD or AD, in a large cohort of DLB cases and controls. The cohort comprised 788 DLB cases and 2624 controls. To minimize the issue of potential misdiagnosis, we have also performed the analysis including only neuropathologically proven DLB cases (667 cases). The results show that the APOE is a strong genetic risk factor for DLB, confirming previous findings, and that the SNCA and SCARB2 loci are also associated after a study-wise Bonferroni correction, although these have a different association profile than the associations reported for the same loci in PD. We have previously shown that the p.N370S variant in GBA is associated with DLB, which, together with the findings at the SCARB2 locus, suggests a role for lysosomal dysfunction in this disease. These results indicate that DLB has a unique genetic risk profile when compared with the two most common neurodegenerative diseases and that the lysosome may play an important role in the etiology of this disorder. We make all these data available.

The prevalence and incidence of dementia with Lewy bodies: a systematic review of population and clinical studies

BACKGROUND

Dementia with Lewy bodies (DLB) is increasingly recognized as a common cause of dementia in older people. However, its true frequency remains unclear, with previous studies reporting a prevalence range from zero to 22.8% of all dementia cases. This review aimed to establish the population prevalence and incidence for DLB and to compare this to its prevalence in secondary care settings.

METHOD

A literature review of all relevant population and clinical studies was conducted using PubMed. Additional references from papers found during that process were added to this.

RESULTS

DLB accounted for 4.2% of all diagnosed dementias in the community. In secondary care this increased to 7.5%. The incidence of DLB was 3.8% of new dementia cases. There was a significant increase in DLB diagnoses when using the revised (2005) International Consensus Criteria (ICC) for DLB compared to the original (1996) criteria.

CONCLUSIONS

DLB currently accounts for around one in 25 dementia cases diagnosed in the community and one in 13 cases in secondary care. The significantly higher rates of DLB in secondary care may reflect enhanced diagnostic accuracy in specialist settings and/or the increased morbidity and carer burden of the DLB syndrome compared to other dementias. However, the true prevalence is likely to be much higher because DLB diagnoses are often missed, although there is evidence that new criteria aid case identification.

[Dementia: Where are the Lewy bodies?]

Dementia with Lewy bodies (DLB) is the second cause of degenerative dementia in autopsy studies. In clinical pratice however, the prevalence of DLB is much lower with important intercenter variations. Among the reasons for this low sensitivity of DLB diagnosis are (1) the imprecision and subjectivity of the diagnostic criteria; (2) the underestimation of non-motor symptoms (REM-sleep behavior disorder, dysautonomia, anosmia); mostly (3) the nearly constant association of Lewy bodies with Alzheimer's disease pathology, which dominates the clinical phenotype. With the avenue of targeted therapies against the protein agregates, new clinical scales able to apprehend the coexistence of Lewy pathology in Alzheimer's disease are expected.

Dementia with Lewy bodies

Dementia with Lewy bodies (DLB) is the second most common cause of neurodegenerative dementia in older people, accounting for 10% to 15% of all cases, it occupies part of a spectrum that includes Parkinson's disease and primary autonomic failure. All these diseases share a neuritic pathology based upon abnormal aggregation of the synaptic protein α-synuciein. It is important to identify DLB patients accurately because they have specific symptoms, impairments, and functional disabilities thai differ from other common dementia syndromes such as Alzheimer's disease, vascular cognitive impairment, and frontotemporal dementia. Clinical diagnostic criteria for DLB have been validated against autopsy, but fail to detect a substantial minority of cases with atypical presentations that are often due to the presence of mixed pathology. DLB patients frequently have severe neuroleptic sensitivity reactions, which are associated with significantly increased morbidity and mortality. Cholinesterase inhibitor treatment is usually well tolerated and substantially improves cognitive and neuropsychiatrie symptoms. Although virtually unrecognized 20 years ago, DLB could within this decade become one of the most treatable neurodegenerative disorders of late life.

[Psychopathological syndromes of neurological diseases in the elderly]

Vascular and degenerative diseases of the central nervous system are one of the most common health problems in the elderly. Cognitive dysfunction, mood disorders and behavioural changes as well as psychotic symptoms constitute an invariable part of the clinical manifestation of these diseases. Psychopathological syndromes influence management decisions, commonly being a reason for patients' institutionalization; they are also a cause of suffering of patients and their caregivers and relatives. Relevant diagnosis of psychological symptoms is crucial in establishing adequate therapy, which improves quality of life of patients and their caregivers. The paper provides an overview of the psychopathological presentation of the most common central nervous system diseases in the elderly.

Differential response of the central noradrenergic nervous system to the loss of locus coeruleus neurons in Parkinson's disease and Alzheimer's disease

In Parkinson's disease (PD), there is a significant loss of noradrenergic neurons in the locus coeruleus (LC) in addition to the loss of dopaminergic neurons in the substantia nigra (SN). The goal of this study was to determine if the surviving LC noradrenergic neurons in PD demonstrate compensatory changes in response to the neuronal loss, as observed in Alzheimer's disease (AD). Tyrosine hydroxylase (TH) and dopamine β-hydroxylase (DBH) mRNA expression in postmortem LC tissue of control and age-matched PD subjects demonstrated a significant reduction in the number of noradrenergic neurons in the LC of PD subjects. TH mRNA expression/neuron did not differ between control and PD subjects, but DBH mRNA expression/neuron was significantly elevated in PD subjects compared to control. This increase in DBH mRNA expression in PD subjects is not a response to neuronal loss because the amount of DBH mRNA expression/neuron in AD subjects was not significantly different from control. Norepinephrine transporter (NET) binding site concentration in the LC of PD subjects was significantly reduced over the cell body region as well as the peri-LC dendritic zone. In PD subjects, the loss of dendrites from surviving noradrenergic neurons was also apparent with TH-immunoreactivity (IR). This loss of LC dendritic innervation in PD subjects as measured by TH-IR was not due to LC neuronal loss because TH-IR in AD subjects was robust, despite a similar loss of LC neurons. These data suggest that there is a differential response of the noradrenergic nervous system in PD compared to AD in response to the loss of LC neurons.

Cerebrospinal fluid biomarkers for dementia with lewy bodies

More than 750,000 of the UK population suffer from some form of cognitive impairment and dementia. Of these, 5–20% will have Dementia with Lewy Bodies (DLB). Clinico-pathological studies have shown that it is the low frequency of DLB clinical core features that makes the DLB diagnosis hardly recognisable during life, and easily misdiagnosed for other forms of dementia. This has an impact on the treatment and long-term care of the affected subjects. Having a biochemical test, based on quantification of a specific DLB biomarker within Cerebrospinal Fluid (CSF) could be an effective diagnostic method to improve the differential diagnosis. Although some of the investigated DLB CSF biomarkers are well within the clinical criteria for sensitivity and specificity (>90%), they all seem to be confounded by the contradictory data for each of the major groups of biomarkers (α-synuclein, tau and amyloid proteins). However, a combination of CSF measures appear to emerge, that may well be able to differentiate DLB from other dementias: α-synuclein reduction in early DLB, a correlation between CSF α-synuclein and Aβ42 measures (characteristic for DLB only), and t-tau and p-tau181 profile (differentiating AD from DLB).

Alzheimer's and non-alzheimer's dementia: a critical review of pharmacological and nonpharmacological strategies

OBJECTIVE

Dementia is an age-related progressive neurodegenerative disorder afflicting about 5% of the world's population, and it is expected to grow dramatically in the future keeping in view our ageing society. Currently available medications appear to be able to produce moderate symptomatic benefits but do not to stop disease progression. In this article, the management of the disorder, including the currently available drugs as well as psychosocial strategies, is discussed.

METHODS

A computerized search on Pubmed from 1980 to 2006 was carried out and all articles evaluated and graded on NICE guidelines.

RESULTS AND CONCLUSIONS

Currently evaluated and accepted medications only bring about a reduction in the deteriorating course. A combination of pharmacotherapy and psychosocial management is the need of the hour.

Hippocampal shape differences in dementia with Lewy bodies

To assess the morphological changes of the hippocampus in Lewy body dementia (LBD) patients we used radial atrophy mapping, a mathematical modeling method sensitive to subtle differences in hippocampal shape. T1-weighted high resolution magnetic resonance (MR) scans were acquired from 14 LBD and 28 controls of similar age and gender, and were compared to those of 28 patients with Alzheimer's disease (AD) described previously. MR images were normalized by linear (12 parameter) transformation to a customized template. The hippocampal formation was isolated by manual tracing. Group differences were assessed with algorithms that average hippocampal shapes across subjects, using three-dimensional parametric surface mesh models. In LBD patients, significant tissue loss amounting to 10-20% was found in the hippocampal subregions corresponding to the anterior portion of the CA1 field on both sides, along the longitudinal midline in the dorsal aspect within the CA2-3 field, and in the subiculum and presubiculum. The direct comparisons between LBD and AD patients showed that this pattern of local atrophy is different from that characteristic of AD. LBD pattern of hippocampal atrophy might be related to the peculiar neuropathology of the disease.

A review of cognitive impairments in dementia with Lewy bodies relative to Alzheimer's disease and Parkinson's disease with dementia

Dementia with Lewy bodies (DLB) has recently been identified as a separate disease but diagnosis can be difficult, in particular the differentiation from related dementias of Alzheimer's disease (AD) and Parkinson's disease with dementia (PDD). Careful cognitive assessment may aid differential diagnosis between these different types of dementia and can provide theoretical insight into the nature of the underlying impairments. Recent reviews on DLB have primarily dealt with medical issues of clinical diagnostic criteria, pathology, epidemiology and treatment (Ballard, 2004; Barber et al., 2001; Cercy and Bylsma, 1997; Cummings, 2004; Kaufer, 2004; McKeith, 2002; McKeith et al., 2004a; Rampello et al., 2004) and only a few papers have reviewed cognitive impairments in DLB (Collerton et al., 2003; Lambon-Ralph et al., 2001; Simard et al., 2000). The present paper is more specifically targeted to a neuropsychological audience. It provides an up-to-date, detailed and comprehensive review of the available evidence regarding visual and olfactory perception, attention, cognitive fluctuation, frontal-executive functions, working memory, episodic memory, and semantic memory in DLB relative to AD and PDD. In addition, an attempt is made to relate available data to current theoretical frameworks of cognition. Implications for future research and clinical issues such as the problem of differential diagnosis, and the relation between cognitive impairments and clinical features of visual hallucinations and cognitive fluctuation will be discussed.

Calpain-cleavage of alpha-synuclein: connecting proteolytic processing to disease-linked aggregation

Parkinson's disease (PD) and dementia with Lewy bodies (DLB) are both characterized pathologically by the presence of neuronal inclusions termed Lewy bodies (LBs). A common feature found in LBs are aggregates of alpha-synuclein (alpha-Syn), and although it is now recognized that alpha-Syn is the major building block for these toxic filaments, the mechanism of how this occurs remains unknown. In the present study, we demonstrate that proteolytic processing of alpha-Syn by the protease calpain I leads to the formation of aggregated high-molecular weight species and adoption of a beta-sheet structure. To determine whether calpain-cleavage of alpha-Syn occurs in PD and DLB, we designed site-directed calpain-cleavage antibodies to alpha-Syn and tested their utility in several animal model systems. Detection of calpain-cleaved alpha-Syn was evident in mouse models of cerebral ischemia and PD and in a Drosophila model of PD. In the human PD and DLB brain, calpain-cleaved alpha-Syn antibodies immunolabeled LBs and neurites in the substantia nigra. Moreover, calpain-cleaved alpha-Syn fragments identified within LBs colocalized with activated calpain in neurons of the PD and DLB brains. These findings suggest that calpain I may participate in the disease-linked aggregation of alpha-Syn in various alpha-synucleinopathies.

Changes in adrenoreceptors in the prefrontal cortex of subjects with dementia: evidence of compensatory changes

In Alzheimer's disease (AD) there is a significant loss of locus coeruleus (LC) noradrenergic neurons. However, recent work has shown the surviving noradrenergic neurons to display many compensatory changes, including axonal sprouting to the hippocampus. The prefrontal cortex (PFC) is a forebrain region that is affected in dementia, and receives innervation from the LC noradrenergic neurons. Reduced PFC function can reduce cognition and disrupt behavior. Because the PFC is an important area in AD, we determined if noradrenergic innervation from the LC noradrenergic neurons is maintained and if adrenoreceptors are altered postsynaptically. Presynaptic PFC alpha2-adrenoreceptor (AR) binding site density, as determined by 3H-RX821002, suggests that axons from surviving noradrenergic neurons in the LC are sprouting to the PFC of subjects with dementia. Changes in postsynaptic alpha1-AR in the PFC of subjects with dementia indicate normal to elevated levels of binding sites. Expression of alpha1-AR subtypes (alpha1A- and alpha1D-AR) and alpha2C-AR subtype mRNA in the PFC of subjects with dementia is similar to what was observed in the hippocampus with one exception, the expression of alpha1A-AR mRNA. The expression of the alpha1A-AR mRNA subtype is significantly reduced in specific layers of the PFC in subjects with dementia. The loss of alpha1A-, alpha1D- and alpha2C-AR mRNA subtype expression in the PFC may be attributed to neuronal loss observed in dementia. These changes in postsynaptic AR would suggest a reduced function of the PFC. Consequence of this reduced function of the PFC in dementia is still unknown but it may affect memory and behavior.

Aggressive behaviour by people with dementia in residential care settings: a review

This paper considers the phenomenon of aggressive behaviour perpetrated by people with dementia in residential care settings. Aggressive behaviour is defined in the context of people with dementia, and the problem of ascertaining the incidence of aggression among people with dementia is discussed. The emotional impact of assaults on nurses and other professionals is highlighted, and differing perspectives on the causation of aggressive behaviour are considered. Management strategies derived from the physical/pharmacological; environment management; behaviour modification and person-centred approaches are reviewed. Our conclusion is that while certain strategies appear to reflect good and common sense practice, in particular those deriving from the person-centred approach, there is no clear research evidence for the general effectiveness of any one management approach, and each has drawbacks of a practical or ethical nature. There is also little empirical information about how professional carers actually manage aggressive behaviour in practice.

Compensatory changes in the noradrenergic nervous system in the locus ceruleus and hippocampus of postmortem subjects with Alzheimer's disease and dementia with Lewy bodies

In Alzheimer's disease (AD), there is a significant loss of locus ceruleus (LC) noradrenergic neurons. However, functional and anatomical evidence indicates that the remaining noradrenergic neurons may be compensating for the loss. Because the noradrenergic system plays an important role in learning and memory, it is important to determine whether compensation occurs in noradrenergic neurons in the LC and hippocampus of subjects with AD or a related dementing disorder, dementia with Lewy bodies (DLB). We observed profound neuronal loss in the LC in AD and DLB subjects with three major changes in the noradrenergic system consistent with compensation: (1) an increase in tyrosine hydroxylase (TH) mRNA expression in the remaining neurons; (2) sprouting of dendrites into peri-LC dendritic zone, as determined by alpha2-adrenoreceptors (ARs) and norepinephrine transporter binding sites; and (3) sprouting of axonal projections to the hippocampus as determined by alpha2-ARs. In AD and DLB subjects, the postsynaptic alpha1-ARs were normal to elevated. Expression of alpha1A- and alpha2A-AR mRNA in the hippocampus of AD and DLB subjects were not altered, but expression of alpha1D- and alpha2C-AR mRNA was significantly reduced in the hippocampus of AD and DLB subjects. Therefore, in AD and DLB subjects, there is compensation occurring in the remaining noradrenergic neurons, but there does appear to be a loss of specific AR in the hippocampus. Because changes in these noradrenergic markers in AD versus DLB subjects were similar (except neuronal loss and the increase in TH mRNA were somewhat greater in DLB subjects), the presence of Lewy bodies in addition to plaques and tangles in DLB subjects does not appear to further affect the noradrenergic compensatory changes.

Cholinesterase inhibitors for Parkinson's disease dementia

BACKGROUND

The loss of cholinergic, dopaminergic and noradrenergic innervations seen in Parkinson's Disease Dementia (PDD) suggest a potential role for cholinesterase inhibitors. Concerns have been expressed about a theoretical worsening of Parkinson's disease related symptoms particularly movement symptoms.

OBJECTIVES

To assess the efficacy, safety, tolerability and health economic data relating to the use of cholinesterase inhibitors in PDD.

SEARCH STRATEGY

The trials were identified from the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group on 19 April 2005 using the search term parkinson*This register contains records from major health care databases and many ongoing trial databases and is updated regularly.Comprehensive searches of abstracts from major scientific meetings were performed. Pharmaceutical companies were approached for information regarding additional and ongoing studies.

SELECTION CRITERIA

Randomized, double-blind, placebo-controlled studies assessing the effectiveness of cholinesterase inhibitors in PDD. Inclusion and exclusion criteria were stated to limit bias.

DATA COLLECTION AND ANALYSIS

Two reviewers (IM, CF) independently reviewed the quality of the studies utilising criteria from the Cochrane Collaboration Handbook. Medications were examined separately and as a group. The outcome measures assessed were in the following domains: neuropsychiatric features, cognition, global impression, daily living activities, quality of life, burden on caregiver, Parkinsonian related symptoms, treatment acceptability as determined by withdrawal from trials, safety as determined by the frequency of adverse events, institutionalisation, death and health economic factors.

MAIN RESULTS

A detailed and systematic search of relevant databases identified one published randomized, double-blind, placebo-controlled study (Emre 2004) involving 541 patients that compared rivastigmine with placebo. Rivastigmine produced statistically significant improvements in several outcome measures. On the primary cognitive measure, the ADAS-Cog, rivastigmine was associated with a 2.80 point ADAS-Cog improvement [WMD -2.80, 95% Cl -4.26 to -1.34, P = 0.0002] and a 2.50 point ADCS-ADL improvement [95% Cl 0.43 to 4.57, P = 0.02] relative to placebo. Clinically meaningful (moderate or marked) improvement occurred in 5.3% more patients on rivastigmine, and meaningful worsening occurred in 10.1% more patients on placebo. Tolerability appeared to be a significant issue. Significantly more patients on rivastigmine dropped out of the study due to adverse events [62/362 versus 14/179, OR 2.44, 95% Cl 1.32 to 4.48, P = 0.004]. Nausea [20/179 versus 105/362, OR 3.25, 95% Cl 1.94 to 5.45, P < 0.00001], tremor [7/179 versus 37/362, OR 2.80, 95% Cl 1.22 to 6.41, P = 0.01] and in particular vomiting [3/179 versus 60/362, OR 11.66, 95% Cl 3.60 to 37.72, P < 0.0001] were significantly more common with rivastigmine. However, significantly fewer patients died on rivastigmine than placebo [4/362 versus 7/179, OR 0.27, 95% CI 0.08 to 0.95, P = 0.04]

AUTHORS' CONCLUSIONS

Rivastigmine appears to improve cognition and activities of daily living in patients with PDD. This results in clinically meaningful benefit in about 15% of cases. There is a need for more studies utilising pragmatic measures such as time to residential care facility and both patient and carer quality of life assessments. Future trials should involve other cholinesterase inhibitors, utilise tools to analyse the data that limit any bias and measure health economic factors. It is unlikely that relying solely on the last observation carried forward (LOCF) is sufficient. Publication of the observed case data in the largest trial would assist (Emre 2004). Adverse events were associated with the cholinergic activity of rivastigmine, but may limit patient acceptability as evidenced by the high drop out rate in the active arm.

Dementia with Lewy bodies: current concepts

As life expectancy continues to increase over time, dementia is becoming an increasingly more common problem and a major cause of disability in older persons. It is now more important than ever to identify and manage common causes of dementia given variations in disease course, treatments and the possibility for modification of risk factors. Dementia with Lewy bodies (DLB) is a dementia syndrome characterized by progressive cognitive decline, with fluctuating cognition, recurrent detailed and well-formed hallucinations, and parkinsonism. This article aims to provide an overview of current concepts of DLB, including a description of the key clinical features and neuropathology, neurochemistry, and genetics of DLB, then a discussion of the relationship of DLB with Alzheimer's disease and Parkinson's disease, and, finally, a summary of current management strategies available for this disorder.

Late-life depression: a model for medical classification

Geriatric psychiatric syndromes might serve as the starting point for a medical classification of psychiatric disorders, because their medical and neurological comorbidity and their clinical, neuropsychological, and neuroimaging features often reflect specific brain abnormalities. Geriatric syndromes, however, consist of complex behaviors that are unlikely to be caused by single lesions. We propose a model in which aging-related changes in specific brain structures increase the propensity for the development of certain psychiatric syndromes. The predisposing factors are distinct from the mechanisms mediating the expression of a syndromic state, much like hypertension is distinct from stroke, but constitutes a morbid vulnerability. We argue that research seeking to identify both brain abnormalities conferring vulnerability as well as the mediating mechanisms of symptomatology has the potential to lead to a medical classification of psychiatric disorders. In addition, a medical classification can guide the effort to improve treatment and prevention of psychiatric disorders as it can direct therapeutic efforts to the underlying predisposing abnormalities, the syndrome-mediating mechanisms, and to development of behavioral skills needed for coping with adversity and disability.

A review of studies describing the use of acetyl cholinesterase inhibitors in Parkinson's disease dementia

OBJECTIVE

To review the literature relating to the use of acetyl cholinesterase inhibitors in Parkinson's disease dementia (PDD).

METHOD

MEDLINE (1966--December 2004), PsychINFO (1972--December 2004), EMBASE (1980--December 2004), CINHAL (1982--December 2004), and the Cochrane Collaboration were searched in December 2004.

RESULTS

Three controlled trials and seven open studies were identified. Efficacy was assessed in three key domains: cognitive, neuropsychiatric and parkinsonian symptoms.

CONCLUSION

Cholinesterase inhibitors have a moderate effect against cognitive symptoms. There is no clear evidence of a noticeable clinical effect against neuropsychiatric symptoms. Tolerability including exacerbation of motor symptoms--in particular tremor--may limit the utility of cholinesterase inhibitors.

Behavioural symptoms of dementia in residential settings: a selective review of non-pharmacological interventions

For people with dementia living in residential settings, behaviours such as aggression, screaming, restlessness, agitation and wandering are a frequent reason for referral to specialist mental health services for older people. Psychosocial models of dementia have grown in prominence and non-pharmacological interventions have been recommended in professional and government policy statements, either as a first line of treatment or alongside medication. Studies of their effectiveness have been criticised for being poorly controlled, focusing on milder behaviour problems and for requiring a disproportionate use of resources. The recent ruling that risperidone and olanzepine should not be used to control behavioural symptoms in dementia makes it timely to review the evidence for alternative treatments. The current review is a selective one of different types of studies including studies of staff training and liaison interventions, studies of a range of different therapeutic interventions and individualized interventions within a single-case methodology. It is argued that different types of research methodology are appropriate for different studies and that there is still too little evidence to provide firm guidelines. In conclusion, a structured decision-making process for selection of interventions is proposed, in which the limited available evidence can be drawn together to provide a basis for targeting clinical resources while the research evidence is strengthened.

Involvement of α6/α3 neuronal nicotinic acetylcholine receptors in neuropsychiatric features of Dementia with Lewy bodies: [125I]-α-conotoxin MII binding in the thalamus and striatum

Dementia with Lewy bodies (DLB) is a neurodegenerative disease associated with a range of neuropsychiatric symptoms and reduced expression of neuronal nicotinic acetylcholine receptors (nAChRs) in neocortex, hippocampus, thalamus and basal ganglia. To determine whether there are selective associations between alterations in alpha6/alpha3 neuronal nicotinic acetylcholine receptors (nAChRs) and the two key neuropsychiatric features of DLB, impaired consciousness (IC) and visual hallucinations (VH), quantitative [(125)I]-alpha-conotoxin MII ([(125)I]-alpha-Ctx MII) autoradiography was undertaken on 28 people with DLB and 15 control cases from the Newcastle Brain Bank. There was a highly significant overall trend for reduced thalamic [(125)I]-alpha-Ctx MII binding in DLB (p < 0.001), with significant deficits in the centromedian, ventral lateral and ventroposterior medial thalamic nuclei (p < 0.05), together with caudate and putamen (p < 0.001). [(125)I]-alpha-Ctx MII binding was significantly lower in DLB cases with IC than without IC in the putamen (p < 0.05), however there was no significant association between [(125)I]-alpha-Ctx MII binding and VH. Reductions in [(125)I]-alpha-Ctx MII binding in caudate and putamen were paralleled by similar reductions in [(125)I]PE2I binding. [(125)I]PE2I binding was also significantly lower in DLB cases with IC than without IC in the caudate (p < 0.05) and putamen (p < 0.001). These results demonstrate that deficits in alpha6/alpha3 nAChRs occur in specific brain regions in DLB, may in part be related to the loss of dopaminergic neurons and may contribute to the development of impaired consciousness in the disorder.

Alleviation of multiple abnormalities by galantamine treatment in two patients with dementia with Lewy bodies

Two patients diagnosed with dementia with Lewy bodies (DLB) presented with prominent behavioral disturbances. The first patient experienced well-formed visual hallucinations, movement disorders, and cognitive decline and was increasingly resistant to care. He was treated with galantamine 4 mg bid, which was increased to 8 mg bid after four weeks. Improvements in behavior, attention, and cognition made it possible for this patient to be transferred back to long-term care after 32 days. The second patient had increasing confusion, fluctuating cognition, agitation, and psychosis. He was given donepezil initially, then switched to galantamine 4 mg bid. He was assessed as stable for discharge with improved behavior control after three weeks. Both patients also were receiving an atypical antipsychotic (quetiapine) and an antidepressant (venlafaxine and sertraline, respectively).

Hallucinations et démences

Hallucinations are a common feature of certain degenerative diseases with a risk of dementia such as Alzheimer's disease, Lewy body dementia, and Parkinson's disease. Obtaining valid epidemiological data is nevertheless quite difficult because of methodological problems. As a rule, hallucinations are more prevalent in Lewy body disease than Parkinson's disease or Alzheimer's disease. The prevalence in parkinsonian dementia is about the same as in Lewy body disease. Complex visual hallucinations predominate, auditory or tactile hallucinations are more exceptional. Minor forms (illusions, sensation of presence) are also observed. Recurrence is common, mainly in the evening or at night. Patients with advanced mental impairment generally take the hallucinations for reality. The hallucinations can be associated with psychological and behavioral disorders such as delusionnal idea or identification disorders. It is important to search for other causes of hallucinations such as drugs, ocular disorders, or depression, but many of these disorders are common comorbidities in elderly patients with degenerative disease. There is no unique model fitting all the hypothesized pathogenic mechanisms. Complex visual hallucinations most likely arise from abnormal activation of the extra-striat temporal associative regions, but only hypothetical mechanisms have been proposed. Genetic studies and functional imaging have not provided convincing evidence. Current focus is placed on an imbalance between deficient cholinergic transmission and preserved or augmented monoaminergic transmission at the cortical level, but other neurotransmission systems could be involved. The dream dysregulation mechanism proposed in Parkinson's disease cannot be generalized. The link between cognitive disorders and hallucination is also poorly understood: hallucinations are associated with more severe cognitive impairments or more rapid cognitive deline in Parkinson's disease and Alzheimer's disease, but the association with specific cognitive disorders remains to be fully explored.

Dementia with Lewy bodies

Dementia with Lewy bodies (DLB) is the second commonest cause of neurodegenerative dementia in older people. It is part of the range of clinical presentations that share a neuritic pathology based on abnormal aggregation of the synaptic protein alpha-synuclein. DLB has many of the clinical and pathological characteristics of the dementia that occurs during the course of Parkinson's disease. Here we review the current state of scientific knowledge on DLB. Accurate identification of patients is important because they have specific symptoms, impairments, and functional disabilities that differ from those of other common types of dementia. Severe neuroleptic sensitivity reactions are associated with significantly increased morbidity and mortality. Treatment with cholinesterase inhibitors is well tolerated by most patients and substantially improves cognitive and neuropsychiatric symptoms. Clear guidance on the management of DLB is urgently needed. Virtually unrecognised 20 years ago, DLB could within this decade be one of the most treatable neurodegenerative disorders of late life.

What happens when donepezil is suddenly withdrawn? An open label trial in dementia with Lewy bodies and Parkinson's disease with dementia

BACKGROUND

This open label study was designed to assess the effects of donepezil treatment, its withdrawal and subsequent recommencement on cognitive functioning, behaviour and parkinsonian symptoms in patients with probable dementia with Lewy bodies (DLB) and with Parkinson's disease who subsequently developed dementia (PDD).

METHODS

Eight patients with DLB and 11 with PDD were treated with up to 10 mg of donepezil daily for 20 weeks followed by a 6-week withdrawal period. The primary outcome measures were the Mini-Mental State Examination (MMSE), the total Neuropsychiatric Inventory (NPI) and the Unified Parkinson's Disease Rating Scale III. Testing was conducted before dosing, at week 20, at a withdrawal visit and 3 months after recommencement on donepezil.

RESULTS

Patients with DLB and PDD showed a significant improvement in cognition with treatment, loss of this improvement on withdrawal and restoration of treatment gains on recommencement. Both groups also demonstrated favourable, behavioural changes with treatment, PDD patients in particular deteriorating significantly after withdrawal. The only NPI symptom domain that showed a consistent significant response to both treatment (positive) and withdrawal (negative) was hallucinations. The medication was well tolerated and parkinsonian features did not alter significantly over the testing sessions.

CONCLUSIONS

Our results suggest that treatment with donepezil improves cognition and hallucinations without increasing parkinsonian symptoms, and its sudden withdrawal is usually detrimental, producing acute cognitive and behavioural decline. Although recommencement on donepezil appears to reverse this deterioration we do not advise its abrupt discontinuation in this population.

Clinical predictors of response to Acetyl Cholinesterase Inhibitors: experience from routine clinical use in Newcastle

BACKGROUND

Acetyl Cholinesterase Inhibitors (AChEIs) have been in clinical use for the past five years in the UK for the symptomatic treatment of Alzheimer's disease (AD). There are few data on the patterns and predictors of response to AChEI therapy in routine clinical practice. We therefore investigated clinical variables that may distinguish between AChEI responders and non-responders.

METHODS

A retrospective sample of 160 consecutive patients with dementia who were treated on clinical grounds with an AChEI was studied. Treatment response was defined in two ways: (a) A clinical response was achieved when there was no deterioration or there was an improvement on a global clinical assessment (CGI) and (b) a Mini-Mental-State-Examination (MMSE) response when there was an improvement of 2 or more MMSE points.

RESULTS

A total of 62 (45%) patients achieved an MMSE response. A diagnosis of dementia with Lewy Bodies (DLB) and Parkinson's disease+Dementia (PDD) was associated with a MMSE response, as were hallucinations, and lower MMSE scores at baseline. 125 (78%) patients achieved a CGI response for which there were no clinical predictors.

CONCLUSIONS

Severity of illness, a diagnosis of DLB and PDD, and presence of hallucinations at baseline were predictive of a MMSE response. Non-AD dementia and severe dementia responded equally well to AChEI treatment and results of further randomised, placebo-controlled studies are needed to clarify the role of AChEI in the treatment of these disorders.

Attenuation of MPTP-induced dopaminergic neurotoxicity by TV3326, a cholinesterase-monoamine oxidase inhibitor

(R)-[(N-propargyl-(3R) aminoindan-5-yl) ethyl methyl carbamate] (TV3326) is a novel cholinesterase and brain-selective monoamine oxidase (MAO)-A/-B inhibitor. It was developed for the treatment of dementia co-morbid with extra pyramidal disorders (parkinsonism), and depression. On chronic treatment in mice it attenuated striatal dopamine depletion induced by MPTP and prevented the reduction in striatal tyrosine hydroxylase activity, like selective B and non-selective MAO inhibitors. TV3326 preferentially inhibits MAO-B in the striatum and hippocampus, and the degree of MAO-B inhibition correlates with the prevention of MPTP-induced dopamine depletion. Complete inhibition of MAO-B is not necessary for full protection from MPTP neurotoxicity. Unlike that seen after treatment with other MAO-A and -B inhibitors, recovery of striatal and hippocampal MAO-A and -B activities from inhibition by TV3326 did not show first-order kinetics. This has been attributed to the generation of a number of metabolites by TV3326 that cause differential inhibition of these enzymes. Inhibition of brain MAO-A and -B by TV3326 resulted in significant elevations of dopamine, noradrenaline and serotonin in the striatum and hippocampus. This may explain its antidepressant-like activity, resembling that of moclobemide in the forced-swim test in rats.

Functional brain imaging applications to differential diagnosis in the dementias

PURPOSE OF REVIEW

The diagnosis of dementia rests on an improved knowledge and a better detection of early impairments, to which functional imaging can certainly contribute.

RECENT FINDINGS

Progress has been observed at different levels. First, the understanding of different dementias has benefited from explorations of the neural substrate of dementia symptoms and from research into new markers. Second, diverse variables (clinical, anatomical, biochemical) have been related to impaired cerebral activity in Alzheimer's disease and other dementias, and progress in image analysis and in multimodal data acquisition has allowed a better understanding of the significance of brain activity disturbances. Third, functional imaging has been applied in well-designed clinical studies, and has provided important arguments for the diagnosis of characteristic clinical syndromes in the dementias.

SUMMARY

The functioning of neural networks responsible for clinical symptoms in dementia remains an important research topic for functional imaging. The development of new tracers and new techniques for image processing should also improve the usefulness of brain imaging as a diagnostic tool.