[Presenile dementia in memory clinics--incidence rates and clinical features]

Dementia subtypes, cognitive decline and survival among older adults attending a memory clinic in Cape Town, South Africa: a retrospective study

BACKGROUND

There are no published longitudinal studies from Africa of people with dementia seen in memory clinics. The aim of this study was to determine the proportions of the different dementia subtypes, rates of cognitive decline, and predictors of survival in patients diagnosed with dementia and seen in a memory clinic.

METHODS

Data were collected retrospectively from clinic records of patients aged ≥ 60 seen in the memory clinic at Groote Schuur Hospital, Cape Town, South Africa over a 10-year period. Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria were used to identify patients with Major Neurocognitive Disorders (dementia). Additional diagnostic criteria were used to determine the specific subtypes of dementia. Linear regression analysis was used to determine crude rates of cognitive decline, expressed as mini-mental state examination (MMSE) points lost per year. Changes in MMSE scores were derived using mixed effects modelling to curvilinear models of cognitive change, with time as the dependent variable. Multivariable cox survival analysis was used to determine factors at baseline that predicted mortality.

RESULTS

Of the 165 patients who met inclusion criteria, 117(70.9%) had Major Neurocognitive Disorder due to Alzheimer's disease (AD), 24(14.6%) Vascular Neurocognitive Disorder (VND), 6(3.6%) Dementia with Lewy Bodies (DLB), 5(3%) Parkinson disease-associated dementia (PDD), 3(1.8%) fronto-temporal dementia, 4(2.4%) mixed dementia and 6(3.6%) other types of dementia. The average annual decline in MMSE points was 2.2(DLB/PDD), 2.1(AD) and 1.3(VND). Cognitive scores at baseline were significantly lower in patients with 8 compared to 13 years of education and in those with VND compared with AD. Factors associated with shorter survival included age at onset greater than 65 (HR = 1.82, 95% C.I. 1.11, 2.99, p = 0.017), lower baseline MMSE (HR = 1.05, 95% C.I. 1.01, 1.10, p = 0.029), Charlson's comorbidity scores of 3 to 4 (HR = 1.88, 95% C.I. 1.14, 3.10, p = 0.014), scores of 5 or more (HR = 1.97, 95% C.I. 1.16, 3.34, p = 0.012) and DLB/PDD (HR = 3.07, 95% C.I. 1.50, 6.29, p = 0.002). Being female (HR = 0.59, 95% C.I.0.36, 0.95, p = 0.029) was associated with longer survival.

CONCLUSIONS

Knowledge of dementia subtypes, the rate and factors affecting cognitive decline and survival outcomes will help inform decisions about patient selection for potential future therapies and for planning dementia services in resource-poor settings.

Chronic seizures induce sex-specific cognitive deficits with loss of presenilin 2 function

Patients with early-onset Alzheimer's disease (EOAD) are at elevated risk for seizures, including patients with presenilin 2 (PSEN2) variants. Like people with epilepsy, uncontrolled seizures may worsen cognitive function in AD. While the relationship between seizures and amyloid beta accumulation has been more thoroughly investigated, the role of other drivers of seizure susceptibility in EOAD remain relatively understudied. We therefore sought to define the impact of loss of normal PSEN2 function and chronic seizures on cognitive function in the aged brain. Male and female PSEN2 KO and age- and sex-matched wild-type (WT) mice were sham or corneal kindled beginning at 6-months-old. Kindled and sham-kindled mice were then challenged up to 6 weeks later in a battery of cognitive tests: non-habituated open field (OF), T-maze spontaneous alternation (TM), and Barnes maze (BM), followed by immunohistochemistry for markers of neuroinflammation and neuroplasticity. PSEN2 KO mice required significantly more stimulations to kindle (males: p < 0.02; females: p < 0.02) versus WT. Across a range of behavioral tests, the cognitive performance of kindled female PSEN2 KO mice was most significantly impaired versus age-matched WT females. Male BM performance was generally worsened by seizures (p = 0.038), but loss of PSEN2 function did not itself worsen cognitive performance. Conversely, kindled PSEN2 KO females made the most BM errors (p = 0.007). Chronic seizures also significantly altered expression of hippocampal neuroinflammation and neuroplasticity markers in a sex-specific manner. Chronic seizures may thus significantly worsen hippocampus-dependent cognitive deficits in aged female, but not male, PSEN2 KO mice. Our work suggests that untreated focal seizures may worsen cognitive burden with loss of normal PSEN2 function in a sex-related manner.

Prevalence and incidence of young onset dementia and associations with comorbidities: A study of data from the French national health data system

BACKGROUND

Dementia onset in those aged <65 years (young onset dementia, YOD) has dramatic individual and societal consequences. In the context of population aging, data on YOD are of major importance to anticipate needs for planning and allocation of health and social resources. Few studies have provided precise frequency estimates of YOD. The aim of this study is to provide YOD prevalence and incidence estimates in France and to study the contribution of comorbidities to YOD incidence.

METHODS AND FINDINGS

Using data from the French national health data system (Système National des Données de Santé, SNDS) for 76% of the French population aged 40 to 64 years in 2016 (n = 16,665,795), we identified all persons with dementia based on at least 1 of 3 criteria: anti-Alzheimer drugs claims, hospitalization with the International Classification of Diseases-10th Revision (ICD-10) dementia codes (F00 to F03, G30, G31.0, G31.1, or F05.1), or registration for free healthcare for dementia. We estimated prevalence rate (PR) and incidence rate (IR) and estimated the association of comorbidities with incident YOD. Sex differences were investigated. We identified 18,466 (PRstandardized = 109.7/100,000) and 4,074 incident (IRstandardized = 24.4/100,000 person-years) persons with prevalent and incident YOD, respectively. PR and IR sharply increased with age. Age-adjusted PR and IR were 33% (95% confidence interval (CI) = 29 to 37) and 39% (95% CI = 31 to 48) higher in men than women (p < 0.001 both for PR and IR). Cardio- and cerebrovascular, neurological, psychiatric diseases, and traumatic brain injury prevalence were associated with incident YOD (age- and sex-adjusted p-values <0.001 for all comorbidities examined, except p = 0.109 for antihypertensive drug therapy). Adjustment for all comorbidities explained more than 55% of the sex difference in YOD incidence. The lack of information regarding dementia subtypes is the main limitation of this study.

CONCLUSIONS

We estimated that there were approximately 24,000 and approximately 5,300 persons with prevalent and incident YOD, respectively, in France in 2016. The higher YOD frequency in men may be partly explained by higher prevalence of cardiovascular and neurovascular diseases, substance abuse disorders, and traumatic brain injury and warrants further investigation.

[Died from or with dementia? The relationship between dementia and cause of death]

Specifying a singular specific cause of death or an appropriate causal chain in the death certificate can be challenging, especially in cases of elderly, multimorbid deceased persons.The German cause of death statistics suggest that mental illnesses, including dementia, are beneath the most frequent causes of death. But when looking at death certificates in the context of dementia considerable information gaps and a lack of plausibility in the causal chain can be observed quite regularly.In this article we give recommendations for the correct designation of the cause of death and underlying diseases in the death certificate. These recommendations are not only to be seen against an academic background. The correct registration of dementia in the causes of death statistics may be a basis for decision making in health politics and is hence in the interest of optimal patient care.

Prevalence and subtype distribution of early-onset dementia in Japan

AIM

People living with early-onset dementia (EOD) have specific social needs. Epidemiological studies are needed to obtain current information and provide appropriate service planning. This study aimed to clarify the current prevalence and subtype distribution of EOD, as well as the services frequently used by individuals with EOD.

METHODS

A multisite, population-based, two-step study was conducted. Questionnaires were sent to 26 416 candidate facilities in 12 areas with a target population of 11 630 322 to inquire whether any individuals with EOD had sought services or stayed during the last 12 months (step 1). When "yes" responses were received, additional questionnaires were sent to the facilities both to complete and to distribute to the target individuals with EOD to obtain more detailed information, including the dementia subtype (step 2).

RESULTS

In step 1, valid responses were obtained from 16 848 facilities (63.8%), and 4077 cases were identified. In step 2, detailed information was obtained for 1614 cases (39.6%) from the facilities and 530 cases (13.0%) from the individuals. The national EOD prevalence rate was estimated to be 50.9/100 000 population at risk (95% confidence interval: 43.9-57.9; age range, 18-64 years). The number of individuals with EOD was estimated to be 35 700 as of 2018. Alzheimer-type dementia (52.6%) was the most frequent subtype, followed by vascular dementia (17.1%), frontotemporal dementia (9.4%), dementia due to traumatic brain injury (4.2%), dementia with Lewy bodies/Parkinson's disease dementia (4.1%), and dementia due to alcohol-related disorders (2.8%). Individuals with EOD were most frequently identified at medical centers for dementia.

CONCLUSION

The prevalence rate estimated in this study was comparable to those in previous studies in Japan. However, the subtype distribution differed, with Alzheimer-type dementia being the most prominent. Based on the case identification frequencies, medical centers for dementia are expected to continue to function as the primary special health service by providing quality diagnosis and post-diagnostic support for individuals with EOD.

[Young onset dementia]

Hintergrund

Aufgrund des demographischen Wandels sind Demenzen ein häufiger und dramatisch zunehmender Grund für ärztliche Vorstellungen. In etwa 8 % der Fälle treten sie bereits vor dem 65. Lebensjahr auf. Gerade bei jüngeren Patienten sind die psychosozialen und ökonomischen Folgen oft gravierend. Die Behandler stehen vor großen diagnostischen Herausforderungen. Eine rasche Diagnose ist für das Patientenmanagement von zentraler Bedeutung.

Ziel der Arbeit/Fragestellung

Dieser Übersichtsartikel stellt die Besonderheiten der Demenzen bei jüngeren Menschen sowie die wichtigsten zugrunde liegenden Krankheitsbilder vor und vermittelt ein strukturiertes klinisch-diagnostisches Vorgehen.

Methoden

Narrativer Review. Die Literatursuche wurde in PubMed durchgeführt.

Ergebnisse

Das differenzialdiagnostische Spektrum von Demenzen bei jüngeren Menschen vor dem 65. Lebensjahr ist sehr breit. Die häufigsten Ursachen stellen die Alzheimer-Krankheit mit typischen oder atypischen klinischen Präsentationen sowie die frontotemporale Lobärdegeneration dar. Je jünger das Erkrankungsalter, desto höher ist der Anteil an behandelbaren und potenziell reversiblen Ursachen eines demenziellen Syndroms.

Diskussion

Die Diagnostik primär neurodegenerativer Erkrankungen hat sich zunehmend verbessert, insbesondere unter Berücksichtigung einer stetig steigenden Zahl an klinischen, molekularen und bildgebenden Biomarkern. Dennoch muss die Diagnostik der Demenzen mit frühem Erkrankungsbeginn hypothesengeleitet erfolgen, d. h. nach einer präzisen klinisch-syndromalen Zuordnung der Symptome. So können unnötige und belastende Untersuchungen vermieden werden.

Early-onset Alzheimer Disease and Its Variants

PURPOSE OF REVIEW

Early-onset Alzheimer disease (AD) is defined as having an age of onset younger than 65 years. While early-onset AD is often overshadowed by the more common late-onset AD, recognition of the differences between early- and late-onset AD is important for clinicians.

RECENT FINDINGS

Early-onset AD comprises about 5% to 6% of cases of AD and includes a substantial percentage of phenotypic variants that differ from the usual amnestic presentation of typical AD. Characteristics of early-onset AD in comparison to late-onset AD include a larger genetic predisposition (familial mutations and summed polygenic risk), more aggressive course, more frequent delay in diagnosis, higher prevalence of traumatic brain injury, less memory impairment and greater involvement of other cognitive domains on presentation, and greater psychosocial difficulties. Neuroimaging features of early-onset AD in comparison to late-onset AD include greater frequency of hippocampal sparing and posterior neocortical atrophy, increased tau burden, and greater connectomic changes affecting frontoparietal networks rather than the default mode network.

SUMMARY

Early-onset AD differs substantially from late-onset AD, with different phenotypic presentations, greater genetic predisposition, and differences in neuropathologic burden and topography. Early-onset AD more often presents with nonamnestic phenotypic variants that spare the hippocampi and with greater tau burden in posterior neocortices. The early-onset AD phenotypic variants involve different neural networks than typical AD. The management of early-onset AD is similar to that of late-onset AD but with special emphasis on targeting specific cognitive areas and more age-appropriate psychosocial support and education.

Membrane Aging as the Real Culprit of Alzheimer's Disease: Modification of a Hypothesis

Our previous studies proposed that Alzheimer's disease (AD) is a metabolic disorder and hypothesized that abnormal brain glucose metabolism inducing multiple pathophysiological cascades contributes to AD pathogenesis. Aging is one of the great significant risk factors for AD. Membrane aging is first prone to affect the function and structure of the brain by impairing glucose metabolism. We presume that risk factors of AD, including genetic factors (e.g., the apolipoprotein E ε4 allele and genetic mutations) and non-genetic factors (such as fat, diabetes, and cardiac failure) accelerate biomembrane aging and lead to the onset and development of the disease. In this review, we further modify our previous hypothesis to demonstrate "membrane aging" as an initial pathogenic factor that results in functional and structural alterations of membranes and, consequently, glucose hypometabolism and multiple pathophysiological cascades.

Early-Onset Alzheimer Disease

Early-onset Alzheimer disease (EOAD), with onset in individuals younger than 65 years, although overshadowed by the more common late-onset AD (LOAD), differs significantly from LOAD. EOAD comprises approximately 5% of AD and is associated with delays in diagnosis, aggressive course, and age-related psychosocial needs. One source of confusion is that a substantial percentage of EOAD are phenotypic variants that differ from the usual memory-disordered presentation of typical AD. The management of EOAD is similar to that for LOAD, but special emphasis should be placed on targeting the specific cognitive areas involved and more age-appropriate psychosocial support and education.

Gender-related protection from or vulnerability to severe CNS diseases: gonado-structural and/or gonado-activational? A meta-analysis of relevant epidemiological studies

BACKGROUND

A vast scientific literature has dealt with gender-specific risk for brain disorder. That field is evolving toward a consensus to the effect that the estrogen hormone family is outstandingly and uniquely neuroprotective. However, the epidemiology relevant to this general outlook remains piecemeal.

METHOD

The present investigation strategically formats the relevant epidemiological findings around the world in order to quantitatively meta-analyze gender ratio of risk for a variety of relevant severe central nervous system (CNS) diseases at all three gonadal stages of the life cycle, pre pubertal, post adolescent/pre menopausal, and post menopausal.

RESULTS

The data quantitatively establish that (1) no single epidemiological study should be cited as evidence of gender-specific neuroprotection against the most common severe CNS diseases because the gender-specific risk ratios are contradictory from one study to the other; (2) risk for severe CNS disease is indeed significantly gender-specific, but either gender can be protected: it depends on the disease, not at all on the age bracket.

CONCLUSION

Our assay of gender-specific risk for severe brain disease around the world has not been able to support the idea according to which any one gender-prevalent gonadal steroid hormone dominates as a neuroprotective agent at natural concentrations.

Epidemiology of early-onset dementia: a review of the literature

Presenile Dementia or Early Onset Dementia (EOD) is a public health problem, it differs from Senile Dementia, and encloses a significant number of cases; nevertheless, it is still poorly understood and underdiagnosed. This study aims to review the prevalence and etiology of EOD, comparing EOD with Senile Dementia, as well as to show the main causes of EOD and their prevalence in population and non-population based studies. The computer-supported search used the following databases: Pubmed/Medline, ISI Web of Knowledge and Scielo. The search terms were alcohol-associated dementia, Alzheimer's disease, dementia, Creutzfeldt-jakob disease, dementia with lewy bodies, early onset dementia, frontotemporal lobar degeneration, Huntington's disease, mixed dementia, neurodegenerative disorders, Parkinson's disease dementia, presenile dementia, traumatic brain injury, vascular dementia. Only papers published in English and conducted from 1985 up to 2012 were preferentially reviewed. Neurodegenerative diseases are the most common etiologies seen in EOD. Among the general population, the prevalence of EOD was found to range between 0 to 700 per 100.000 habitants in groups of 25-64 years old, with an increasing incidence with age. The progression of EOD was found to range between 8.3 to 22.8 new cases per 100.000 in those aged under 65 years. Alzheimer's disease (AD) is the major etiology, followed by Vascular Dementia (VaD) and Frontotemporal Lobar Degeneration (FTLD). A larger number of epidemiological studies to elucidate how environmental issues contribute to EOD are necessary, thus, we can collaborate in the planning and prevention of services toward dementia patients.

Early-onset Alzheimer's disease: nonamnestic subtypes and type 2 AD

Patients with Alzheimer's disease (AD), the most prevalent neurodegenerative dementia, are usually elderly; however, ∼4-5% develop early-onset AD (EOAD) with onset before age 65. Most EOAD is sporadic, but about 5% of patients with EOAD have an autosomal dominant mutation such as Presenilin 1, Presenilin 2, or alterations in the Amyloid Precursor Protein gene. Although most Alzheimer's research has concentrated on older, late-onset AD (LOAD), there is much recent interest and research in EOAD. These recent studies indicate that EOAD is a heterogeneous disorder with significant differences from LOAD. From 22-64% of EOAD patients have a predominant nonamnestic syndrome presenting with deficits in language, visuospatial abilities, praxis, or other non-memory cognition. These nonamnestic patients may differ in several ways from the usual memory or amnestic patients. Patients with nonamnestic EOAD compared to typical amnestic AD have a more aggressive course, lack the apolipoprotein Eɛ4 (APOE ɛ4) susceptibility gene for AD, and have a focus and early involvement of non-hippocampal areas of brain, particularly parietal neocortex. These differences in the EOAD subtypes indicate differences in the underlying amyloid cascade, the prevailing pathophysiological theory for the development of AD. Together the results of recent studies suggest that nonamnestic subtypes of EOAD constitute a Type 2 AD distinct from the usual, typical disorder. In sum, the study of EOAD can reveal much about the clinical heterogeneity, predisposing factors, and neurobiology of this disease.

Frontal-executive versus posterior-perceptual mental status deficits in early-onset dementias

BACKGROUND

Compared to late-onset dementias, early-onset dementias (EODs) may have greater focal cognitive involvement with differences in frontal-executive compared to posterior-perceptual deficits.

OBJECTIVE

This study evaluated whether mental status screening based on this frontal-posterior axis can distinguish EODs.

METHODS

Twenty-three patients each with early-onset Alzheimer's disease (eAD), frontotemporal dementia (FTD), or subcortical ischemic vascular disease (SIVD), and 20 normal controls underwent the Frontal Assessment Battery (FAB) and the Perceptual Assessment Battery (PAB).

RESULTS

Compared to controls, SIVD and FTD groups were impaired on the FAB whereas eAD and SIVD groups were impaired on the PAB. The FAB/PAB ratio further differentiated the groups (F(3,85) = 26.49, P < .001). For sensitivities and specificities of 93%, a cut-off score of 1.25 on the FAB/PAB distinguished eAD, and a cut-off of 0.83 distinguishing FTD.

CONCLUSION

Although preliminary, this study indicates that mental status screening based on frontal versus posterior cortical functions may help clinicians diagnose EODs.