Dementing Process Research Articles

Caregiver Accounts of Lucid Episodes in Persons With Advanced Dementia.

Paradoxical lucidity is defined as an instance of unexpected lucid behavior in a person who is assumed to be noncommunicative due to a progressive and pathophysiologic dementing process. To inform studies of the prevalence, characteristics, and impact of these behaviors, this interview study examined caregivers' experiences of witnessing paradoxical lucidity. Participants were family caregivers of persons living with advanced dementia caused by a neurodegenerative disease producing significant impairments in communication. Semistructured interviews elicited the caregivers' experiences of plausible lucid episodes. Data analysis used a thematic analysis approach. Most caregivers reported at least 1 episode of lucidity. Episodes were typically brief. Most involved utterances, but nonverbal behaviors were also common. The mental capacities associated with these behaviors included recognition, awareness of surroundings, recognizing others' emotions, and goal-directed behavior. Most caregivers' reactions were positive. Episodes did not lead to changes in major medical decisions but instead to efforts to either modify or reinforce daily caregiving efforts. Episodes of lucidity were common, a finding seen in other studies. If prevalence studies confirm this, the qualifier "paradoxical" should be eliminated. The caregivers' familiarity with the person living with dementia allowed them to attribute meaning to subtle behaviors that might not otherwise be detected or considered lucid. Clinicians who care for persons with advanced-stage dementia should routinely ask caregivers about episodes of lucid communication and their emotional reactions.

Neurophysiological features associated with suicidal risk in dementias

IntroductionThe bioelectrical activity of the brain of suicidals has specific features.ObjectivesInvestigate neurophysiological features associated with high suicidal risk (SR) in dementias.MethodsAn electroencephalographic study of brain was performed in 66 patients with dementia, of which 33 (with high SR) were included in the main group, the other 33 (with low SR) – in the control group.ResultsSR correlates include an increase in the spectral density and amplitude (in μV) of the α-rhythm in the right central (C4) (109.4) – in the main group, compared with (64.5) – in the control; in the temporal areas (T4) (132.2) - in the main group, (70.0) – in the control group (p<0.001). The predominance of the spectral density of the slow θ-rhythm over the entire surface of the brain (p<0.001) and δ-rhythm in the projection of Fp2 (82.3) – in the main and (116.1) – in the control groups (p<0.001), F3 (54.80) and (68.1), respectively, (p<0.05), F4 (52.4) and (67.3), respectively, (p<0.01), C4 (52.0) and (62.0), respectively (p<0.05), P3 (44.4) and (58.9), respectively, (p<0.01), O1 (67.6) and (89.41), (p<0.001), O2 (68.5) and (85.8), respectively (p<0.001) are a predictor of low SR in dementias.ConclusionsWith the progression of changes in the brain in dementias SR decreases. In the initial phases of the dementing process with a relatively preserved functional capacity of the brain SR is high.DisclosureNo significant relationships.

Social network structure and dementing processes

AbstractBackgroundHow are components of individual social relationships associated with the dementing process? We examined associations between social network structure on incidence of mild cognitive impairment (MCI) and conversion to probable dementia, and on mortality rate.MethodWe utilized six waves of a nationally representative cohort of residents aged over 65 years and older in the United States (2011‐2016; National Health and Aging Trends Study; NHATS). Respondents were categorized into normal cognition, MCI, or probable dementia. Four‐status multi‐state survival models (MSMs) were used to provide multivariable‐adjusted measures, fit with a misclassification matrix, assessed effects of social network structure on the dementing process.ResultEligible NHATS participants (N=6,078) were mostly female (58.42%), and the majority were Non‐Hispanic white (68.99%). At baseline, the average age was 77.49±7.79 years and respondents reported an average number of 1.93 ±1.31 members of their social networks. In multivariable‐adjusted MSMs accounting for age, sex, education and race/ethnicity, having larger social networks was associated with lower hazards of conversion from MCI to probable dementia (adjusted Hazard Ratio (aHR): 0.82; 95%C.I.=[0.67‐0.99]). Having at least one friend within social network was associated with lower hazards of conversion from MCI to dementia (aHR=0.48 [0.33‐0.71]) but was associated with higher risk of mortality in the MCI group (aHR=2.58 [1.47‐4.51]). Finally, participants with at least one college graduate in their social network reported lower incidence of dementia (aHR=0.37 [0.26‐0.51]).ConclusionOur study is one of the first studies exploring effects of social network structure on the dementing process in a nationally representative prospective cohort of older adults. We found that having at least one friend, a larger social network, or having a college graduate within social network was associated with lower risk of MCI or conversion to dementia. We also reveal substantial disparities in cognitive dementing by education and race/ethnicity as well as clustering risks for low‐educated families.

Associations of olfaction with mild cognitive impairment and cognitive function in older adults: A population‐based study

AbstractBackgroundOlfactory function might be impaired in the early stage of the dementing process, and thus, olfactory test may be useful for identifying elderly persons at an increased risk. However, previous studies that investigate the relationship between olfactory function and cognitive phenotypes have been scarcely conducted among older people living in the rural communities and the associations of olfaction with specific cognitive remains unclear. We sought to examine the relationship of olfactory function with global cognitive ability and various domains of cognitive function among rural‐dwelling Chinese older adults.MethodThis population‐based cross‐sectional study included 3003 dementia‐free participants (age ≥65 years; 57.3% women; 37.7% illiterate) in the baseline examination (March‐September 2018) of the Multidomain Interventions to Delay Dementia and Disability in Rural China (MIND‐CHINA) study. The 16‐item Sniffin’ Sticks identification test (SSIT) was performed to assess olfactory function. Global cognitive function was evaluated with the Chinese version of the Mini‐Mental State Examination (MMSE) and a neuropsychological battery was used to assess memory, language, attention, and executive function. We followed the Petersen’s criteria to define mild cognitive impairment (MCI). Data were analysed with multiple logistic regression and the general linear regression models.ResultOf the 3003 participants, MCI was defined in 335 persons (11.2%). Multiple logistic regression analysis suggested that SSIT score (range 0‐16) was associated with an odds ratio of 0.90 (95% CI 0.87‐0.93) for MCI. Multiple general linear regression analysis showed that SSIT score was significantly associated with the scores of MMSE test (β coefficient=0.07, 95% CI 0.03‐0.11), z‐score of memory (β coefficient=0.28, 95% CI 0.12‐0.45), language (β coefficient=0.35, 95% CI 0.17‐0.52), and attention (β coefficient=0.59, 95% CI 0.38‐0.78), but not with the z‐score of executive function (β coefficient=0.05, 95% CI ‐0.11‐0.22).ConclusionA greater olfactory identification ability is associated with a lower likelihood of MCI and better performances in global cognitive function, attention, memory, and language function, but not in executive function, among Chinese older adults who are living in the rural communities with limited education.

Associations of sleep characteristics with mild cognitive impairment and dementia among Chinese elderly people living in a rural area: A population‐based study

AbstractBackgroundSleep patterns might be changed in the early stage of the dementing process. Thus, sleep characteristics may be useful markers for identifying elderly persons at risk of mild cognitive impairment (MCI) and dementia. However, previous studies that investigated the associations of sleep characteristics and cognitive function have been scarcely conducted among Chinese older adults. We aim to determine the associations of various sleep characteristics with MCI and dementia among rural‐dwelling Chinese elderly people.MethodThis population‐based cross‐sectional study included 4680 participants who were aged ≥65 years and living in the rural communities in Yanggu County, Shandong Province. In March‐September 2018, we collected data through interviews, clinical examinations, cognitive testing, and laboratory tests. We used Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS) to evaluate sleep characteristics such as sleep duration, sleep efficiency, and excessive daytime sleepiness (EDS). Cognitive function was assessed with a neuropsychological test battery. Dementia was diagnosed based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria, and MCI was defined according to the modified Petersen’s criteria. Multiple multinomial logistic regression models were used to examine the associations of sleep characteristics with MCI or dementia.ResultOf the 4680 participants, 195 were diagnosed with dementia and 691 with MCI. Compare to the sleep duration of 4‐8 hours/night, the multivariable‐adjusted odds ratio (95% confidence interval) of MCI and dementia was 1.34 (1.01, 1.77) and 1.97 (1.25, 3.12) for very short sleep duration (≤4 hours/night), and 1.35 (1.06, 1.72) and 1.74 (1.11, 2.74) for long sleep duration (>8 hours/night). The EDS was significantly associated with the adjusted odds ratio of 1.36 (1.05, 1.78) for MCI and 1.80 (1.15, 2.84) for dementia. Moreover, low sleep efficiency was associated with an adjusted odds ratio of 1.65 (1.18, 2.30) for dementia and 1.10 (0.91, 1.33) for MCI.ConclusionLong and very short sleep duration and EDS were associated with an elevated likelihood of MCI and dementia among rural‐dwelling Chinese older adults. In addition, low sleep efficiency was associated with a high likelihood of dementia but not MCI.

Psychotherapeutic support for persons with vascular dementia suffering from non-cognitive psychopathological symptoms of non-psychotic level

Introduction. In addition to cognitive deficit, the presence of a dementing process of vascular origin leads to changes in the patient’s personality, as well as in his character. Persons with vascular dementia always have non-cognitive disease manifestations of non-psychotic level. Non-psychotic psychopathological symptoms can lead to a significant deterioration of the well-being and quality of life of patients with vascular dementia, and therefore should be taken into account when drawing up a plan for treatment and rehabilitation of such patients. Psychotherapy interventions play the most important role in management of patients with vascular dementia. The aim of the study: to develop a targeted model of psychotherapeutic support based on the selective correction of non-cognitive psychopathological symptoms of non-psychotic level in patients with vascular dementia. Materials and methods: The study was carried out on 80 patients with vascular dementia with different localization of the lesion. The average age of the patients was 68.6 years. All persons included in the contingent of the study demonstrated non-cognitive psychopathological symptoms of non-psychotic level. Results. Recommendations for psychocorrection of maladaptive non-cognitive pathopsychological symptomatology of non-psychotic level in persons with vascular dementia have been developed. For each of these symptoms, congruent vectors, mechanisms, and methods of psychotherapeutic correction were identified and described. The basic vector for minimizing and eliminating depression in patients with vascular dementia aimed at shifting the mode of emotional experiences from the negative spectrum to the positive or at least neutral. The basic vector for minimizing and eliminating anxiety in patients with vascular dementia aimed at shifting attention from stressful factors to sanogenic, emotionally neutral stimuli. The basic vector for minimizing and eliminating apathy in patients with vascular dementia aimed at activation of mental processes and restoration of a minimum acceptable level of emotional response. The basic vector for minimizing and eliminating irritability in patients with vascular dementia aimed at increasing the threshold of negative emotional response to environmental stimuli. The basic vector for minimizing and eliminating emotion incontinence in patients with vascular dementia aimed at restoring the ability to control external manifestations of internal feelings.

Alzheimer’s Disease-related Biomarkers in Aging Adults with Down Syndrome: Systematic Review

Background: Down syndrome (DS) is associated with a high prevalence of cognitive impairment and dementia in middle age and older adults. Given the presence of common neuropathological findings and similar pathogenic mechanisms, dementia in DS is regarded as a form of genetically determined, early-onset AD. The clinical characterization of cognitive decline in persons with DS is a difficult task, due to the presence intellectual disability and pre-existing cognitive impairment. Subtle changes that occur at early stages of the dementing process may not be perceived clinically, given that most cognitive screening tests are not sensitive enough to detect them. Therefore, biological markers will provide support to the diagnosis of DS-related cognitive impairment and dementia, particularly at early stages of this process. Objective: To perform a systematic review of the literature on AD-related biomarkers in DS. Method: We searched PubMed, Web of Science and Cochrane Library for scientific papers published between 2008 and 2018 using as primary mesh terms ‘Down’, ‘Alzheimer’, ‘biomarker’. Results: 79 studies were retrieved, and 39 were considered eligible for inclusion in the systematic review: 14 post-mortem studies, 10 neuroimaging, 4 addressing cerebrospinal fluid biomarkers, and 11 on peripheral markers. Conclusion: There is consistent growth in the number of publication in this field over the past years. Studies in DS-related dementia tend to incorporate many of the diagnostic technologies that have been more extensively studied and validated in AD. In many instances, the study of CNS and peripheral biomarkers reinforces the presence of AD pathology in DS.

Serum Adiponectin is Related to Dementia.

The adipokine adiponectin (APN)'s role in Alzheimer's disease (AD) is controversial. Some studies suggest APN is neuroprotective while others propose it has harmful effects. We have used Multiple Indicators Multiple Causes (MIMIC) models to evaluate the effects of serum protein biomarkers on cognitive performance in the Texas Alzheimer's Research and Care Consortium (TARCC) (Royall DR, Bishnoi RJ, Palmer RF. Serum IGF-BP2 strongly moderates age's effect on cognition: a MIMIC analysis. Neurobiol Aging. 2015;36:2232-2240; Bishnoi RJ, Palmer RF, Royall DR. Vitamin D binding protein as a serum biomarker of Alzheimer's disease. J Alzheimers Dis. 2015;43:37-45; Bishnoi RJ, Palmer RF, Royall DR. Serum interleukin (IL)-15 as a biomarker of Alzheimer's disease. PLoS One. 2015;10:e0117282). MIMIC models were constructed and replicated in randomly selected 50% splits of TARCC's data (Group 1 N = 1,691; Group 2 N = 1,690) and used to evaluate the relationship between serum APN levels and cognition. Our approach has been to divide general intelligence (Spearman's g) (Spearman C. The Abilities of Man: Their Nature and Measurement. 1932) into two latent variables, δ (ie, a dementia-specific phenotype representing the disabling fraction of cognitive variance) and g prime (g') (ie, the residual non-disabling fraction). Only effects on δ are likely to be dementing. Serum APN was significantly related to δ scores (r = .10, p = .015). APN had no significant effect on g' (r = -.25, p = .66), nor did it have any independent direct effects on cognitive performance. These results were replicated across random subsets (ΔCHISQ = 2.8(7), p > .90). APN's effect on cognition is mediated through intelligence (ie, δ), likely to be disabling, and therefore to mediate one or more dementing processes. We have previously shown APN to partially mediate age's-specific effect on δ (Royall DR, Al-Rubaye S, Bishnoi R, Palmer RF. Serum protein mediators of dementia and aging proper. Aging (Albany NY). 2016;8:3241-3254). However, because the current model is age adjusted, APN must mediate one or more additional age-independent dementing process(es), possibly AD.

Dementing brain processes in patients with Wilson’s disease and multiple sclerosis (pathogenesis and treatment approaches)

This article discusses various aspects of dementing processes in patients with Wilson’s disease (WD) and multiple sclerosis (MS), followed by a discussion of current pathogenetic treatment methods for these patients. A comprehensive clinical and laboratory study showed that the pathogenesis and staged development of the dementing process in patients with WD and MS largely coincides with those in patients with Alzheimer's disease and depends on three groups of factors: genetic predisposition, natural (biological) aging, and endo and exogenous pathogenic factors effects on the brain. Therefore, on the basis of the data presented by us, as well as literature data, it allows us to state that dementia is an organic pathophysiological syndrome of destruction of the critical mass of structural-functional blocks and systems of cognitive mechanisms of the brain. Each individual has his own, genetically determined, critical mass of cognitive mechanisms. Like any false system, this one is ultimately subject to both natural (slow) decay and pathological (accelerated) decay due to the death of neurons both in the type of apoptosis and in the type of necrosis. Thus, in patients with WD and MS, the pathogenetic process always involves structures sooner or later that ensure the functioning of the cognitive functions of the brain and lead to the development of their defects, therefore, therapy should be prescribed for the treatment of these patients. Dementia should be treated at its early stage, at the stage of cognitive impairment (CI). The general principles of managing patients with CI are the determination of the etiopathogenetic cause underlying the development of cognitive impairment, the reduction in the degree and prevention of the progression of cognitive deficit and the impact, if possible, on risk factors. Also, at all stages of cognitive deficiency, treatment of concomitant somatic diseases and correction of the emotional state are relevant. Therefore, timely prescribed comprehensive, pathogenetically substantiated personified therapy helps prevent irreversible consequences and improves the quality of life of patients.

Protein levels of ADAM10, BACE1, and PSEN1 in platelets and leukocytes of Alzheimer's disease patients.

The clinical diagnosis of Alzheimer's disease (AD) is a probabilistic formulation that may lack accuracy particularly at early stages of the dementing process. Abnormalities in amyloid-beta precursor protein (APP) metabolism and in the level of APP secretases have been demonstrated in platelets, and to a lesser extent in leukocytes, of AD patients, with conflicting results. The aim of the present study was to compare the protein level of the APP secretases A-disintegrin and metalloprotease 10 (ADAM10), Beta-site APP-cleaving enzyme 1 (BACE1), and presenilin-1 (PSEN1) in platelets and leukocytes from 20 non-medicated older adults with AD and 20 healthy elders, and to determine the potential use of these biomarkers to discriminate cases of AD from controls. The protein levels of all APP secretases were significantly higher in platelets compared to leukocytes. We found statistically a significant decrease in ADAM10 (52.5%, p < 0.0001) and PSEN1 (32%, p = 0.02) in platelets from AD patients compared to controls, but not in leukocytes. Combining all three secretases to generate receiver-operating characteristic (ROC) curves, we found a good discriminatory effect (AD vs. controls) when using platelets (the area under the curve-AUC-0.90, sensitivity 88.9%, specificity 66.7%, p = 0.003), but not in leukocytes (AUC 0.65, sensitivity 77.8%, specificity 50.0%, p = 0.2). Our findings indicate that platelets represent a better biological matrix than leukocytes to address the peripheral level of APP secretases. In addition, combining the protein level of ADAM10, BACE1, and PSEN1 in platelets, yielded a good accuracy to discriminate AD from controls.

The Severe Impairment Profile: A Conceptual Shift

The current study sought to evaluate and replicate the severe impairment profile (SIP) of the Word Memory Test (WMT) in patients referred for dementia evaluations. The sample consisted of 125 patients referred for a neuropsychological evaluation at a large Veterans Affairs Medical Center. Patients were assigned a Clinical Dementia Rating (CDR) by blind raters, and were classified according to their performance on performance validity testing. Subsequent chart reviews were conducted to help in more accurately determining the presence of severe memory impairment likely due to an underlying dementing process versus poor effort/task engagement. In our sample, 51% of patients failed easy WMT subtests and 93% of these patients obtained the SIP. The rates of failure on these easy subtests generally coincided with both more severely impaired CDR ratings, as well as more impaired delayed memory composite scores. Upon chart review, it was determined that there were likely a significant portion of classification errors using the SIP, with a positive posttest probability of impairment based on having the SIP being 65% as opposed to 28% for a negative result. Our findings suggest that the SIP does not appear to function effectively in a mixed dementia sample where there is increased potential for secondary gain. Additional concern is expressed regarding the overall likelihood of obtaining the SIP and subsequent inferential decisions related to obtaining an SIP. Future research should examine more optimal cut scores or alternative methods for more accurately classifying patients in different clinical contexts and patterns of impairment.

As queixas subjetivas de memória num cuidado de saúde primário: Um estudo follow up

ObjetivoAs queixas subjetivas de memória (QSM) são um fator clínico relevante e uma das principais queixas feitas aos médicos de família por adultos e adultos idosos. Este estudo, realizado numa Unidade de Saúde Familiar da Região Centro de Portugal, teve como objetivo caracterizar as QSM em função de variáveis sociodemográficas, clínicas, cognitivas, emocionais e de qualidade de vida.MétodoEste estudo, de coorte prospetivo em dois momentos, procurou explorar a evolução das QSM durante 18 meses e quais os fatores que se associam. Foi levado a cabo numa amostra de 19 adultos e de adultos idosos com idades compreendidas entre os 55 e os 81 anos (79.2% do sexo feminino). Os dados foram recolhidos por entrevistas semiestruturadas e sempre que possível foram consultados os processos clínicos. Foram utilizados como instrumentos de medida o Mini Mental State Examination (MMSE), o Montreal Cognitive Assessment (MoCA), a Escala de Queixas de Memória (EQM), a Escala de Depressão Geriátrica (GDS), o Inventário de Ansiedade Geriátrica (GAI), a Avaliação de Qualidade de Vida da Organização Mundial de Saúde (WHOQOL-Bref) e por um questionário sociodemográfico e clínico construído para o efeito.ResultadosNo segundo momento avaliativo, todos os participantes evidenciam QSM, sendo estas influenciadas significativamente pela idade. Houve ainda um aumento da sintomatologia depressiva e ansiógena, dos valores da Hemoglobina glicosilada (HbA1c) e do número de medicamentos consumidos, com particular ênfase nos anti hipertensores.ConclusãoAs QSM deverão ser objeto de preocupação e vigilância do médico de família, uma vez que podem representar um sintoma relevante para a identificação precoce de um processo demencial.

Delirium Versus Dementia: A Diagnostic Conundrum in Clinical Practice

A common requested psychiatric consultation in a hospital setting is for evaluation of an elderly patient with observed changes in cognition and/or agitation. The underlying question is often whether the case represents delirium or preexisting dementia. In cases such as these, identifying the root cause can be a diagnostic quandary in that the patient may have underlying dementia and is inherently an unreliable source. When collateral information from people familiar with the patient is limited, behavioral observations, bedside mental status examination, historical information by medical and nursing staff, and diagnostic tests can be useful. This review attempts to assist the physician in differentiating a patient with delirium from a patient with an underlying dementing process. Additionally, the article reviews the epidemiology, predisposing and precipitating factors, clinical characteristics, diagnosis, and management of the patient who presents with observed changes in cognition and/or agitation. [ Psychiatr Ann . 2017;47(5):239–245. ]

Health characteristics of older police custody detainees in London, UK

The number of older adults involved in the criminal justice system is rising. Little is known about the state of health in older people who are arrested. This study compared characteristics and health care needs of older police custody detainees with their younger counterparts. The health characteristics of 57 police detainees aged over 50 were compared with 543 younger detainees. Older detainees had significantly higher rates of physical illness and risk of alcohol withdrawal. Although there were equivalent rates of mental disorder and drug taking compared with younger detainees, a higher proportion had presentations consistent with cognitive impairment due to possible dementing processes. Over 80% of older detainees were recommended to have a health assessment in police stations based on their presentation. Police detainees over 50 should be considered to have a health assessment as routine procedure. Further investigation should also be conducted into cognitive impairment in this group.

Eating Behaviors and Dietary Changes in Patients With Dementia.

Eating problems and dietary changes have been reported in patients with dementia. The aim of this article is to explore the generalized problems with nutrition, diet, feeding, and eating reported among patients with dementia. Medline and Google Scholar searches were conducted for relevant articles, chapters, and books published before 2016. Search terms used included behavioral and psychological symptoms of dementia, dementia, dietary changes, eating behavior. Publications found through this indexed search were reviewed for further relevant references. Abnormal eating behaviors, eating problems, and dietary changes are present in most people with dementia, especially in the later stages of the condition. Individuals with dementia frequently develop serious feeding difficulties and changes in eating and dietary habits. The changes may be secondary to cognitive impairment or apraxia, or the result of insufficient caregiving, or the consequence of metabolic or neurochemical abnormalities occurring as part of the dementing process.

Lewy Body Spectrum Disorders: from Dementia with Lewy Bodies to Parkinson’s Disease Dementia

Lewy body disorders are common neurodegenerative dementias and their complex features often makes it difficult to provide an accurate diagnosis. They share neuropathological and clinical features with each other as well as with Alzheimer’s disease. There have been some recent advances in biomarkers and neuroimaging, but as of yet, nothing has been conclusive when trying to identify each dementing process. Treatment options have been limited and based on small studies; however, new options are on the horizon. In this article, we will discuss recent advances in the study of Lewy body disorders and how to apply them to clinical practice.

Professor Alois Alzheimer (1864–1915): Lest we forget

December 19th 2015 marks the centennial anniversary of the death of the great Bavarian psychiatrist and neuropathologist, Alois Alzheimer (1864–1915), a man immortalised by the still incurable dementing process described by him in 1906 and firmly established in his name. Notwithstanding the great wealth of research into the history of Alzheimer’s disease and legacy, the life of this exemplary clinician remains less than widely appreciated today, and it is the purpose of this brief reminiscence to retell the story of the pioneering neuropsychiatrist in this centenary year of his passing.

How Clinicians Feel about Working with Spouses of the Chronically Ill.

Clinicians who provide psychotherapy to spouses or partners of the chronically ill were solicited through listserves of psychodynamic and other organizations. The current report excluded those therapists working with spouses of dementia patients. Interviews were conducted with clinicians who responded. The interviews highlight the challenges commonly encountered by psychotherapeutic work with this cohort of therapy patients. A comparison is drawn that shows both overlap and distinctions between the experiences of those therapists engaging with spouses of chronically ill patients without a dementing process and those working with spouses of chronically ill patients who do suffer from a dementing process.

Mild cognitive impairment and Parkinson's disease--something to remember.

Cognitive impairment is common in Parkinson's disease (PD), and many patients will eventually develop a dementia, which has a devastating impact on the patient and their family. As such, there has been much interest in identifying a prodromal state to inform prognosis and facilitate earlier management, similar to the concept of 'MCI' in the Alzheimer's field. However, grouping the early cognitive deficits of PD together as 'PD-MCI' may not be the best way forward as it implies a single aetiological basis with one clinical consequence. In this review, we argue that cognitive deficits in PD arise from a number of different pathological pathways, only some of which herald a dementing process. This has important implications both for treatment of individual patients, and for the design of future disease-modifying therapy trials.

Parkinson's disease dementia: a neural networks perspective.

In the long-term, with progression of the illness, Parkinson's disease dementia affects up to 90% of patients with Parkinson's disease. With increasing life expectancy in western countries, Parkinson's disease dementia is set to become even more prevalent in the future. However, current treatments only give modest symptomatic benefit at best. New treatments are slow in development because unlike the pathological processes underlying the motor deficits of Parkinson's disease, the neural mechanisms underlying the dementing process and its associated cognitive deficits are still poorly understood. Recent insights from neuroscience research have begun to unravel the heterogeneous involvement of several distinct neural networks underlying the cognitive deficits in Parkinson's disease dementia, and their modulation by both dopaminergic and non-dopaminergic transmitter systems in the brain. In this review we collate emerging evidence regarding these distinct brain networks to give a novel perspective on the pathological mechanisms underlying Parkinson's disease dementia, and discuss how this may offer new therapeutic opportunities.