Early-onset dementias: diagnostic and etiological considerations

Utility of Tau PET in the diagnostic work up of neurodegenerative dementia among Indian patients

BACKGROUND AND OBJECTIVES

Tau PET is being increasingly appraised as a novel diagnostic modality for dementia work up. Given limited data among South Asians, we assessed the frequency, patterns, phenotypic associations and incremental value of positive Tau PET scans in clinically diagnosed neurodegenerative dementia.

METHODS

This cross-sectional study recruited consecutive patients of Alzheimer's disease (AD) and non-AD syndromes (September 2021 to October 2022, India). Participants underwent clinical interview, cognitive assessment, MRI brain and tau PET scan ([F-18]ML-104). Visual read in a priori regions of interest was used to identify patterns of tau deposition in the brain.

RESULTS

We recruited 54 participants (mean age: 63.2 ± 9.2 years, 64.8 % men, 77.8 % dementia, 70.4 % early onset cases, 37.8 % APOE4+). The analysis identified abnormal tau uptake in 40/54 (74.1 %) participants; with uptake in AD signature areas in 27/40 (67.5 %) cases [cortical subtype (74.1 %), limbic (14.8 %), combined cortical/limbic (11.1 %)], and patterns not conforming to AD in 13/40 (32.5 %) cases. Tau PET substantiated the diagnosis of AD among 17/19 (89.5 %) cases with clinically diagnosed AD dementia, 8/23 (34.8 %) cases with suspected non-AD cause, and 2/12 (16.7 %) cases with mild cognitive impairment. A trend for increasing proportion of early onset cases, and worsening cognition, behavior and functional ability was seen, from 'limbic' to 'combined cortical/limbic' to 'cortical' subgroups.

CONCLUSION

Tau PET is a useful modality to differentiate AD dementia from other neurodegenerative causes in the Indian setting where amyloid biomarkers are not widely available. Biological subtypes of AD map well onto clinical phenotypes and need study in larger cohorts.

Iron accumulation/overload and Alzheimer's disease risk factors in the precuneus region: A comprehensive narrative review

Alzheimer's disease (AD) is a neurodegenerative disease that is characterized by amyloid plaques, neurofibrillary tangles, and neuronal loss. Early cerebral and body iron dysregulation and accumulation interact with AD pathology, particularly in the precuneus, a crucial functional hub in cognitive functions. Quantitative susceptibility mapping (QSM), a novel post-processing approach, provides insights into tissue iron levels and cerebral oxygen metabolism and reveals abnormal iron accumulation early in AD. Increased iron deposition in the precuneus can lead to oxidative stress, neuroinflammation, and accelerated neurodegeneration. Metabolic disorders (diabetes, non-alcoholic fatty liver disease (NAFLD), and obesity), genetic factors, and small vessel pathology contribute to abnormal iron accumulation in the precuneus. Therefore, in line with the growing body of literature in the precuneus region of patients with AD, QSM as a neuroimaging method could serve as a non-invasive biomarker to track disease progression, complement other imaging modalities, and aid in early AD diagnosis and monitoring.

Association of adherence to the EAT-Lancet diet with risk of dementia according to social economic status: a prospective cohort in UK Biobank

The EAT-Lancet Commission has proposed a reference diet aiming to promote human health and environmental sustainability. Socioeconomic disadvantage and poor diet are well-known risk factors for dementia; however, whether the effect of this reference diet on dementia varies by socioeconomic status has not been investigated. The dietary habits of 190,893 participants from UK-Biobank were assessed; the association of EAT-Lancet diet with incident dementia across socioeconomic status was determined by Cox models. One thousand seven hundred twenty-eight dementia cases were identified during a median of 12.24 years follow-up. An inverse association between adherence to EAT-Lancet diet and all-cause dementia (high vs. low; hazard ratio [HR], 95% confidence interval [CI]: 0.82, 0.72-0.94) or late-onset dementia (high vs. low; HR, 95% CI: 0.78, 0.68-0.91) was observed only in individuals with high socioeconomic status. On the contrary, no protective effects of EAT-Lancet diet on early-onset dementia were observed, regardless of the socioeconomic status. Our findings indicated that adherence to an environment-friendly diet helps attenuate risk of dementia only in individuals with high socioeconomic level.

Diverging Relationships among Amyloid, Tau, and Brain Atrophy in Early-Onset and Late-Onset Alzheimer's Disease

PURPOSE

Alzheimer's disease (AD) dementia may not be a single disease entity. Early-onset AD (EOAD) and late-onset AD (LOAD) have been united under the same eponym of AD until now, but disentangling the heterogeneity according to the age of sonset has been a major tenet in the field of AD research.

MATERIALS AND METHODS

Ninety-nine patients with AD (EOAD, n=54; LOAD, n=45) and 66 cognitively normal controls completed both [18F]THK5351 and [18F]flutemetamol (FLUTE) positron emission tomography scans along with structural magnetic resonance imaging and detailed neuropsychological tests.

RESULTS

EOAD patients had higher THK retention in the precuneus, parietal, and frontal lobe, while LOAD patients had higher THK retention in the medial temporal lobe. Intravoxel correlation analyses revealed that EOAD presented narrower territory of local FLUTE-THK correlation, while LOAD presented broader territory of correlation extending to overall parieto-occipito-temporal regions. EOAD patients had broader brain areas which showed significant negative correlations between cortical thickness and THK retention, whereas in LOAD, only limited brain areas showed significant correlation with THK retention. In EOAD, most of the cognitive test results were correlated with THK retention. However, a few cognitive test results were correlated with THK retention in LOAD.

CONCLUSION

LOAD seemed to show gradual increase in tau and amyloid, and those two pathologies have association to each other. On the other hand, in EOAD, tau and amyloid may develop more abruptly and independently. These findings suggest LOAD and EOAD may have different courses of pathomechanism.

Association between depression and young-onset dementia in middle-aged women

BACKGROUND

Dementia is associated with older adults; however, it can also affect younger individuals, known as young-onset dementia (YOD), when diagnosed before the age of 65 years. We aimed to conduct a retrospective cohort study involving middle-aged women to investigate the association between premorbid depression and YOD development.

METHODS

We included 1.6 million women aged 40-60 years who underwent health checkups under the Korean National Health Insurance Service and investigated the association between depression and YOD.

RESULTS

Women with depression had a significantly higher risk of developing YOD than women without depression. Among premenopausal women, those with depression had a 2.67-fold increased risk, whereas postmenopausal women with depression had a 2.50-fold increased risk. Late age at menarche (> 16 years) and young age at menopause (< 40 years) was associated with an increased risk of YOD.

CONCLUSIONS

Depression in middle-aged women is a significant risk factor for the development of YOD. Understanding the role of reproductive factors can aid in the development of targeted therapeutic interventions to prevent or delay YOD.

Choriocapillaris reduction accurately discriminates against early-onset Alzheimer's disease

INTRODUCTION

This study addresses the urgent need for non-invasive early-onset Alzheimer's disease (EOAD) prediction. Using optical coherence tomography angiography (OCTA), we present a choriocapillaris model sensitive to EOAD, correlating with serum biomarkers.

METHODS

Eighty-four EOAD patients and 73 controls were assigned to swept-source OCTA (SS-OCTA) or the spectral domain OCTA (SD-OCTA) cohorts. Our hypothesis on choriocapillaris predictive potential in EOAD was tested and validated in these two cohorts.

RESULTS

Both cohorts revealed diminished choriocapillaris signals, demonstrating the highest discriminatory capability (area under the receiver operating characteristic curve: SS-OCTA 0.913, SD-OCTA 0.991; P < 0.001). A sparser SS-OCTA choriocapillaris correlated with increased serum amyloid beta (Aβ)42, Aβ42/40, and phosphorylated tau (p-tau)181 levels (all P < 0.05). Apolipoprotein E status did not affect choriocapillaris measurement.

DISCUSSION

The choriocapillaris, observed in both cohorts, proves sensitive to EOAD diagnosis, and correlates with serum Aβ and p-tau181 levels, suggesting its potential as a diagnostic tool for identifying and tracking microvascular changes in EOAD.

HIGHLIGHTS

Optical coherence tomography angiography may be applied for non-invasive screening of Alzheimer's disease (AD). Choriocapillaris demonstrates high sensitivity and specificity for early-onset AD diagnosis. Microvascular dynamics abnormalities are associated with AD.

Utility of the INECO Frontal Screening and the Frontal Assessment Battery in detecting executive dysfunction in early-onset cognitive impairment and dementia

OBJECTIVE

The INECO Frontal Screening (IFS) and the Frontal Assessment Battery (FAB) are executive dysfunction (ED) screening tools that can distinguish patients with neurodegenerative disorders from healthy controls and, to some extent, between dementia subtypes. This paper aims to examine the suitability of these tests in assessing early-onset cognitive impairment and dementia patients.

METHOD

In a memory clinic patient cohort (age mean = 57.4 years) with symptom onset at ≤65 years, we analyzed the IFS and the FAB results of four groups: early-onset dementia (EOD, n = 49), mild cognitive impairment due to neurological causes (MCI-n, n = 34), MCI due to other causes such as depression (MCI-o, n = 99) and subjective cognitive decline (SCD, n = 14). Data were gathered at baseline and at 6 and 12 months. We also studied the tests' accuracy in distinguishing EOD from SCD patients and ED patients from those with intact executive functioning. Correlations with neuropsychological measures were also studied.

RESULTS

The EOD group had significantly (p < .05) lower IFS and FAB total scores than the MCI-o and SCD groups. Compared with the FAB, the IFS showed more statistically significant (p < .05) differences between diagnostic groups, greater accuracy (IFS AUC = .80, FAB AUC = .75, p = .036) in detecting ED and marginally stronger correlations with neuropsychological measures. We found no statistically significant differences in the EOD group scores from baseline up to 6- or 12-months follow-up.

CONCLUSIONS

While both tests can detect EOD among memory clinic patients, the IFS may be more reliable in detecting ED than the FAB.

Effects of risk factors on the development and mortality of early- and late-onset dementia: an 11-year longitudinal nationwide population-based cohort study in South Korea

BACKGROUND

Early-onset dementia (EOD, onset age < 65) and late-onset dementia (LOD, onset age ≥ 65) exhibit distinct features. Understanding the risk factors for dementia development and mortality in EOD and LOD respectively is crucial for personalized care. While risk factors are known for LOD development and mortality, their impact on EOD remains unclear. We aimed to investigate how hypertension, diabetes mellitus, hyperlipidemia, atrial fibrillation, and osteoporosis influence the development and mortality of EOD and LOD, respectively.

METHODS

Using the Korean National Health Insurance Service (NHIS) database, we collected 546,709 dementia-free individuals and followed up for 11 years. In the two study groups, the Younger group (< 65 years old) and the Older group (≥ 65 years old), we applied Cox proportional hazard models to assess risk factors for development of EOD and LOD, respectively. Then, we assessed risk factors for mortality among EOD and LOD.

RESULTS

Diabetes mellitus and osteoporosis increased the risk of EOD and LOD development. Hypertension increased the risk of EOD, while atrial fibrillation increased the risk of LOD. Conversely, hyperlipidemia exhibited a protective effect against LOD development. Additionally, diabetes mellitus increased mortality in EOD and LOD. Hypertension and atrial fibrillation increased mortality in LOD, while hyperlipidemia decreased mortality in EOD and LOD.

CONCLUSIONS

Risk factors influencing dementia development and mortality differed in EOD and LOD. Targeted public health interventions addressing age-related risk factors may reduce dementia incidence and mortality.

Neuropsychological Profiles, Etiologies, and Medical Comorbidities in Early-Onset Dementia and Cognitive Impairment: A Memory Outpatient Clinic Cohort Study

Background

Although early-onset dementia (EOD) is associated with diagnostic challenges that differ from those of related to late-onset dementia, only limited studies have addressed the neuropsychological and health characteristics or specified the diagnoses underlying early-onset cognitive impairment in a real-world clinical setting.

Objective

To investigate the neuropsychological profiles, etiologies, and comorbidities of an unselected cohort of memory clinic patients (≤65 years at symptom onset).

Methods

The patients' (n = 210) diagnoses were determined based on comprehensive diagnostic workup. Medical comorbidities and neuropsychological profiles were compared between clinically relevant patient groups, namely early-onset dementia (n = 55), mild cognitive impairment due to vascular or suspected neurodegenerative (MCI-n, n = 35) or non-neurodegenerative (MCI-o, n = 106) etiologies, and subjective cognitive decline (n = 14).

Results

The most prevalent diagnoses were Alzheimer's disease (AD, 14%) and depression (11%). Multiple prior medical conditions were common (67%); however, EOD patients had fewer other diagnoses (p = 0.008) than MCI-o patients. Compared to other groups, EOD patients had more severe deficits (p < 0.001) on immediate and delayed memory, processing speed, symptom awareness, and global cognition. AD patients had weaker memory retention ability but less behavioral symptoms than frontotemporal dementia (FTD) patients (p≤0.05). Depression was associated with better immediate memory, symptom awareness, and global cognition than AD and FTD (p < 0.05).

Conclusions

EOD is associated with more severe and widespread neuropsychological deficits but fewer prior medical diagnoses than nondegenerative etiologies of cognitive impairment. AD and depression are common etiologies and the neuropsychological profiles are partly overlapping; however, memory, symptom awareness and global cognitive impairment measures may help in the differential diagnosis.

Tau suppresses microtubule-regulated pancreatic insulin secretion

Tau protein is implicated in the pathogenesis of Alzheimer's disease (AD) and other tauopathies, but its physiological function is in debate. Mostly explored in the brain, tau is also expressed in the pancreas. We further explored the mechanism of tau's involvement in the regulation of glucose-stimulated insulin secretion (GSIS) in islet β-cells, and established a potential relationship between type 2 diabetes mellitus (T2DM) and AD. We demonstrate that pancreatic tau is crucial for insulin secretion regulation and glucose homeostasis. Tau levels were found to be elevated in β-islet cells of patients with T2DM, and loss of tau enhanced insulin secretion in cell lines, drosophila, and mice. Pharmacological or genetic suppression of tau in the db/db diabetic mouse model normalized glucose levels by promoting insulin secretion and was recapitulated by pharmacological inhibition of microtubule assembly. Clinical studies further showed that serum tau protein was positively correlated with blood glucose levels in healthy controls, which was lost in AD. These findings present tau as a common therapeutic target between AD and T2DM.

Initial symptoms of early-onset dementia in Japan: nationwide survey

AIM

The aim of this study was to investigate initial symptoms of early-onset dementia (EOD) for each dementia subtype.

METHOD

We conducted a nationwide, population-based EOD prevalence study in Japan. Data were collected through service providers for people with EOD. Initial symptoms were assessed in six domains: loss of memory, difficulty in word generation, irritability, loss of motivation, increased mistakes in the workplace or domestically, and unusual behaviours or attitudes other than those listed.

RESULTS

Participants were 770 people with EOD. Characteristic initial symptoms were observed for each EOD subtype. Loss of memory was more common in early-onset Alzheimer's disease (75.7%, P < 0.001), difficulty in word generation was more common in early-onset vascular dementia (41.3%, P < 0.001), and loss of motivation, increased mistakes in the workplace or domestically, and unusual behaviours or attitudes other than those listed were more common in early-onset frontotemporal dementia (34.9%, P < 0.001; 49.4%, P < 0.001; 34.9%, P < 0.001, respectively). In addition, we observed gender differences whereby loss of memory was more common among women and irritability was more common among men. More than half of the participants were employed at symptom onset, and 57.2% of those who were employed at the onset had initial symptoms of increased mistakes in the workplace or domestically.

CONCLUSION

This report reveals differences in the frequency of initial symptoms by EOD subtype. The results contribute to increasing public awareness of the initial symptoms of EOD, which will facilitate early diagnosis and social support.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy: Atypical clinical presentation with isolated frontotemporal dementia

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary syndrome caused by heterozygous mutations in the NOTCH3 gene that manifests in adulthood and is characterized by recurrent transient ischemic attacks and strokes, migraine-like headaches, psychiatric disturbance, and progressive dementia. The current study reports an interesting case of CADASIL in a Saudi patient with a heterozygous mutation in exon 18 of the NOTCH3 gene presenting only with cognitive decline without migraine or stroke. The diagnosis was suspected mainly because of the typical brain magnetic resonance imaging (MRI) features that led to performing genetic testing to confirm the diagnosis. This illustrates the importance of brain MRI in the diagnosis of CADASIL. Increased awareness of neurologists and neuroradiologists about the typical MRI features of CADASIL is of paramount importance to reach the diagnosis in a timely manner. Awareness of the atypical presentations of CADASIL will lead to identifying more CADASIL cases.

Cognitive impairment following traumatic brain injury in Uganda: Prevalence and associated factors

BACKGROUND

As the burden of dementia continues to rise in sub-Saharan Africa, it is crucial to develop an evidence base for potentially modifiable risk factors such as Traumatic Brain Injury (TBI). Cognitive impairment may result from TBI and since it is an established prodromal form of dementia, we investigated the burden of cognitive impairment and associated factors in persons with a history of TBI in southwestern Uganda.

METHODS

This was a community-based quantitative study with a cross-sectional design among 189 persons with a history of TBI in southwestern Uganda. Data were collected by the research team in March and June 2022 and entered into Kobo Toolbox before being transferred to RStudio version 4.1.0 for cleaning and analysis. Data were analyzed at a 5% level of significance.

RESULTS

Most study participants had some form of cognitive impairment (56.1%), with 43.1% of the participants having mild cognitive impairment (MCI). Cognitive impairment was associated with older age (p-value<0.001); loss of consciousness following the TBI (p-value = 0.019) and a history of tobacco use (p-value = 0.003). As a measure of severity of the TBI, loss of consciousness (aOR = 4.09; CI = 1.57-11.76; p<0.01) and older age (aOR = 1.04; CI = 1.01-1.07; p<0.01) were identified as risk factors for cognitive impairment.

CONCLUSION

There is a high burden of cognitive impairment among individuals with a history of TBI in southwestern Uganda, and most associated risk factors are potentially modifiable. Long-term follow-up of TBI patients would enable early identification of some risks. Patients with TBI could benefit from behavioural modifications such as restriction of alcohol intake and tobacco use to slow down the progression into dementia.

Microvascular Changes in the Retina Correlate with MRI Markers in Patients with Early-Onset Dementia

Background and Aims: Recent reports suggest that results from imaging retinal microvascular changes with optical coherence tomography angiography (OCTA) in dementia patients reflect cerebral microcirculation changes that occur during dementia. Macula microvascular impairment has been shown in dementia patients compared to controls, but very little is known about its correlation with radiological visual rating scores associated with dementia. We aimed to explore the association between retinal microvasculature and radiological visual rating in early-onset dementia (EOD) patients. Methods: Swept-source OCTA (SS-OCTA) was used to image the retinal microvasculature of all EOD patients. Automated software in the OCTA tool segmented and measured the densities in the superficial vascular plexus (SVC) and deep vascular plexus (DVC) and foveal avascular zone (FAZ) areas. Radiological visual rating scores were evaluated on all MR images. Results: Medial temporal lobe atrophy (MTA) scores significantly correlated with FAZ area (p = 0.031) in EOD patients after adjusting for risk factors. PWMH correlated with SVC (p = 0.032) while DWMH significantly correlated with SVC (p = 0.007), DVC (p = 0.018) and FAZ (p = 0.001) in EOD patients. Discussion: FAZ changes correlated with MTA scores in EOD patients, while retinal microvasculature correlated with white matter hyperintensity. Our report suggests that microvascular changes in the retina may reflect cortical changes in the brain of EOD patients.

Identification of Early Onset Dementia in Population-Based Health Administrative Data: A Validation Study Using Primary Care Electronic Medical Records

BACKGROUND

Early onset dementia (EOD) occurs when symptoms of dementia begin between 45 to 64 years of age.

OBJECTIVE

We developed and validated health administrative data algorithms for EOD and compared demographic characteristics and presence of comorbid conditions amongst adults with EOD, late onset dementia (LOD) and adults with no dementia in Ontario, Canada.

METHODS

Patients aged 45 to 64 years identified as having EOD in their primary care electronic medical records had their records linked to provincial health administrative data. We compared several combinations of physician's claims, hospitalizations, emergency department visits and prescriptions. Age-standardized incidence and prevalence rates of EOD were estimated from 1996 to 2016.

RESULTS

The prevalence of EOD for adults aged 45 to 64 years in our primary care reference cohort was 0.12% . An algorithm of ≥1 hospitalization or ≥3 physician claims at least 30 days apart in a two-year period or ≥1 dementia medication had a sensitivity of 72.9% (64.5-81.3), specificity of 99.7% (99.7-99.8), positive predictive value (PPV) of 23.7% (19.1-28.3), and negative predictive value of 100.0% . Multivariate logistic regression found adults with EOD had increased odds ratios for several health conditions compared to LOD and no dementia populations. From 1996 to 2016, the age-adjusted incidence rate increased slightly (0.055 to 0.061 per 100 population) and the age-adjusted prevalence rate increased three-fold (0.11 to 0.32 per 100 population).

CONCLUSION

While we developed a health administrative data algorithm for EOD with a reasonable sensitivity, its low PPV limits its ability to be used for population surveillance.

Association of APOE Genotypes and Chronic Traumatic Encephalopathy

Importance

Repetitive head impact (RHI) exposure is the chief risk factor for chronic traumatic encephalopathy (CTE). However, the occurrence and severity of CTE varies widely among those with similar RHI exposure. Limited evidence suggests that the APOEε4 allele may confer risk for CTE, but previous studies were small with limited scope.

Objective

To test the association between APOE genotype and CTE neuropathology and related endophenotypes.

Design, Setting, and Participants

This cross-sectional genetic association study analyzed brain donors from February 2008 to August 2019 from the Veterans Affairs-Boston University-Concussion Legacy Foundation Brain Bank. All donors had exposure to RHI from contact sports or military service. All eligible donors were included. Analysis took place between June 2020 and April 2022.

Exposures

One or more APOEε4 or APOEε2 alleles.

Main Outcomes and Measures

CTE neuropathological status, CTE stage (0-IV), semiquantitative phosphorylated tau (p-tau) burden in 11 brain regions (0-3), quantitative p-tau burden in the dorsolateral frontal lobe (log-transformed AT8+ pixel count per mm2), and dementia.

Results

Of 364 consecutive brain donors (100% male; 53 [14.6%] self-identified as Black and 311 [85.4%] as White; median [IQR] age, 65 [47-77] years) 20 years or older, there were 294 individuals with CTE and 70 controls. Among donors older than 65 years, APOEε4 status was significantly associated with CTE stage (odds ratio [OR], 2.34 [95% CI, 1.30-4.20]; false discovery rate [FDR]-corrected P = .01) and quantitative p-tau burden in the dorsolateral frontal lobe (β, 1.39 [95% CI, 0.83-1.94]; FDR-corrected P = 2.37 × 10-5). There was a nonsignificant association between APOEε4 status and dementia (OR, 2.64 [95% CI, 1.06-6.61]; FDR-corrected P = .08). Across 11 brain regions, significant associations were observed for semiquantitative p-tau burden in the frontal and parietal cortices, amygdala, and entorhinal cortex (OR range, 2.45-3.26). Among football players, the APOEε4 association size for CTE stage was similar to playing more than 7 years of football. Associations were significantly larger in the older half of the sample. There was no significant association for CTE status. Association sizes were similar when donors with an Alzheimer disease neuropathological diagnosis were excluded and were reduced but remained significant after adjusting for neuritic and diffuse amyloid plaques. No associations were observed for APOEε2 status. Models were adjusted for age at death and race.

Conclusions and Relevance

APOEε4 may confer increased risk for CTE-related neuropathological and clinical outcomes among older individuals with RHI exposure. Further work is required to validate these findings in an independent sample.

Safety and Usefulness of Lumbar Puncture for the Diagnosis and Management of Young-Onset Cognitive Disorders

BACKGROUND

Young-onset cognitive disorders (YOCD) often manifests with complex and atypical presentations due to underlying heterogenous pathologies. Therefore, a biomarker-based evaluation will allow for timely diagnosis and definitive management.

OBJECTIVE

Here, we evaluated the safety and usefulness of cerebrospinal fluid (CSF) sampling through lumbar puncture (LP) in YOCD patients in a tertiary clinical setting.

METHODS

Patients with mild cognitive impairment (MCI) and mild dementia with age of onset between 45-64 years were evaluated. Patients underwent magnetic resonance imaging and their medial temporal lobe atrophy (MTA) was rated. LP side-effects and the impact of the CSF findings on diagnosis and management were analyzed.

RESULTS

142 patients (53 (37.32%) MCI, 51 (35.92%) dementia of the Alzheimer's disease [DAT] type, and 38 (26.76%) non-AD type dementia) who underwent LP between 2015 to 2021 were analyzed. Using post-LP results and MTA ratings, 74 (52.11%) patients met the AT(N) criteria for AD. 56 (39.44%) patients (28 out of 53 (50.0%) MCI, 12 out of 51 (21.43%) DAT, and 16 out of 38 (28.57%) non-AD dementia) had a change in diagnosis following LP. 13 (9.15%) patients developed side-effects post-LP (11 (84.62%) patients had headache, 1 (7.69%) patient had backache, and 1 (7.69%) patient had headache and backache). 32 (22.54%) patients had a change in management post-LP, 24 (75.0%) had medication changes, 10 (31.30%) had referrals to other specialists, and 3 (9.40%) was referred for clinical trial with disease modifying interventions.

CONCLUSION

LP is well-tolerated in YOCD and can bring about relevant clinical decisions with regards to the diagnosis and management of this complex clinical condition.

Provisional consensus on the nomenclature and operational definition of dementia at a young age, a Delphi study

OBJECTIVES

Dementia at a young age differs from late onset dementia in pathology and care needs. This requires further research to improve the understanding of this group, support and service provision. Aim of current study is to reach consensus on the terminology and operational definition (i.e., age-related criteria and possible causes) of dementia at a young age, to aid further research.

METHODS

A classical Delphi technique was used to transform opinions into group consensus by using an online survey. In three rounds statements regarding (1) terminology, (2) age-related criteria, and (3) aetiologies that can be considered as causes of dementia at a young age were sent to international experts in the field to give their opinions and additional comments on the statements.

RESULTS

Forty-four experts responded and full consensus was reached on 22 out of 35 statements. Young-onset dementia emerged as the term of preference. Provisional consensus was found for the use of age 65 at symptom onset as preferred cut-off age. Consensus was reached on the inclusion of 15 out of 22 aetiologies and categories of aetiologies as potential cause for dementia at a young age.

CONCLUSIONS

A clear term and operational definition have been reached. Although beneficial for conducting future research to gain more insight in pathology and care needs of young people living with dementia, still consensus about some details is lacking. To reach consensus about these details and implications for use in research and clinical practice, the organisation of an in person consensus meeting is advised.

What do health professionals need to know about young onset dementia? An international Delphi consensus study

Background

People with young onset dementia (YOD) have unique needs and experiences, requiring care and support that is timely, appropriate and accessible. This relies on health professionals possessing sufficient knowledge about YOD. This study aims to establish a consensus among YOD experts about the information that is essential for health professionals to know about YOD.

Methods

An international Delphi study was conducted using an online survey platform with a panel of experts (n = 19) on YOD. In round 1 the panel individually responded to open-ended questions about key facts that are essential for health professionals to understand about YOD. In rounds 2 and 3, the panel individually rated the collated responses in terms of their importance in addition to selected items from the Dementia Knowledge Assessment Scale. The consensus level reached for each statement was calculated using the median, interquartile range and percentage of panel members who rated the statement at the highest level of importance.

Results

The panel of experts were mostly current or retired clinicians (57%, n = 16). Their roles included neurologist, psychiatrist and neuropsychiatrist, psychologist, neuropsychologist and geropsychologist, physician, social worker and nurse practitioner. The remaining respondents had backgrounds in academia, advocacy, or other areas such as law, administration, homecare or were unemployed. The panel reached a high to very high consensus on 42 (72%) statements that they considered to be important for health professionals to know when providing care and services to people with YOD and their support persons. Importantly the panel agreed that health professionals should be aware that people with YOD require age-appropriate care programs and accommodation options that take a whole-family approach. In terms of identifying YOD, the panel agreed that it was important for health professionals to know that YOD is aetiologically diverse, distinct from a mental illness, and has a combination of genetic and non-genetic contributing factors. The panel highlighted the importance of health professionals understanding the need for specialised, multidisciplinary services both in terms of diagnosing YOD and in providing ongoing support. The panel also agreed that health professionals be aware of the importance of psychosocial support and non-pharmacological interventions to manage neuropsychiatric symptoms.

Conclusions

The expert panel identified information that they deem essential for health professionals to know about YOD. There was agreement across all thematic categories, indicating the importance of broad professional knowledge related to YOD identification, diagnosis, treatment, and ongoing care. The findings of this study are not only applicable to the delivery of support and care services for people with YOD and their support persons, but also to inform the design of educational resources for health professionals who are not experts in YOD.

A Systematic Review of the Indirect and Social Costs in Early and Young Onset Dementias

BACKGROUND

The World Health Organization has estimated that worldwide around 50 million people have dementia. The World Alzheimer Report estimated that between 2 and 10% of all cases of dementia begin before the age of 65. Early and young onset dementias (EYOD) provoke more working, social, family, and economic consequences than late onset dementias. All general studies about costs of dementias show that most of them are indirect or social costs. Despite that, very few studies have been performed in EYOD.

OBJECTIVE

To do a systematic review of literature about indirect or social costs in EYOD to know the state of knowledge and to discover gaps that should be filled.

METHODS

A systematic review was performed in the main database: Scopus, PsychInfo, Web of Science (Web of Science Core Collection, Medline and SciELO), and CINAHL. Additionally, we looked for reviews in Cochrane and in the International Prospective Register Of Systematic Reviews (PROSPERO).

RESULTS

Most of the studies are about costs of dementias in general, but they do no differentiate costs for the case of EYOD. Many studies highlight the increased costs for EYOD but very little included evidence of that. 135 papers were selected. Finally, only two were studies providing data. EYOD reduce the odds to get or maintain a job. Most of the care is provided by informal caregivers. The costs in EYOD are 39.26% higher among EYOD than in late onset.

CONCLUSION

There is a lack of studies about social and indirect costs in EYOD. More evidence is needed.

An Integrative Literature Review on the Nomenclature and Definition of Dementia at a Young Age

Background:

There has been growing interest in young people living with dementia. Future research requires consensus on the terminology and operational definition of this group.

Objective:

The purpose of this integrative review was to explore and include all operational definitions used to define dementia at a young age.

Methods:

On August 14, 2020, the PubMed, Embase, Cinahl, and PsycInfo databases were searched for empirical and theoretical literature using Google. Various terms to describe and define ‘dementia’ and ‘at a young age’ were used to collect literature concerning terminology; age-related aspects, including cut-off ages and criteria; and etiologies of dementia at a young age.

Results:

The search yielded 6,891 empirical and 4,660 theoretical publications, resulting in the inclusion of 89 publications, including 36 publications containing an explicit discussion and 53 publications as confirmation. ‘Young-onset dementia’ was the most commonly used term of seven identified terms, in the last two decades. The age of 65 years at symptom onset was used most frequently when considering a total of six upper age limits and four criteria to define a cut-off age. Eight lower age limits and an option for subdivision based on age were included. We identified 251 different etiologies and 27 categories of etiologies.

Conclusion:

Despite relative consensus on the term young-onset dementia and an age at symptom onset being used as a cut-off criterion, much is still unclear concerning possible etiologies of dementia at a young age. In the current study, controversies were detected for discussion in an international consensus study.

Early-onset dementia: key issues using a relationship-centred care approach

People with early-onset dementia have a potential risk of being marginalised with respect to care and social support as a result of the blame and stigma associated with their condition, and because they have reduced access to treatment options and postdiagnostic care. The limited use of community services and the resulting psychological implications are two key issues facing the group and their caregivers. Early diagnosis, behavioural therapies such as talking therapy, meaningful Montessori activities and friendly community services tailored to meet the needs of people with early-onset dementia are relationship-centred care approaches that could be implemented in practice, using the 'Senses Framework' to promote an enriched supportive environment of care with zero tolerance for marginalisation and discriminatory tendencies. Support for caregivers is invaluable in controlling behavioural changes in people with early-onset dementia. A combined approach involving pharmacological and behavioural interventions could be used in severe mood and behavioural changes.

Risk of early-onset dementia among persons with tinnitus: a retrospective case-control study

Higher rates of poor cognitive performance are known to prevail among persons with tinnitus in all age groups. However, no study has explored the association between tinnitus and early-onset dementia. We hypothesize that tinnitus may precede or occur concurrently with subclinical or early onset dementia in adults younger than 65 years of age. This case–control study used data from the Taiwan National Health Insurance Research Database, identifying 1308 patients with early-onset dementia (dementia diagnosed before 65 years of age) and 1308 matched controls. We used multivariable logistic regressions to estimate odds ratios (ORs) for prior tinnitus among patients with dementia versus controls. Among total 2616 sample participants, the prevalence of prior tinnitus was 18%, 21.5% among cases and 14.5% among controls (p < 0.001). Multivariable logistic regression showed and adjusted OR for prior tinnitus of 1.6 for cases versus controls (95% CI: 1.3 ~ 2.0). After adjusting for sociodemographic characteristics and medical co-morbidities, patients with early-onset dementia had a 67% higher likelihood of having prior tinnitus (OR = 1.628; 95% CI = 1.321–2.006). Our findings showed that pre-existing tinnitus was associated with a 68% increased risk of developing early-onset dementia among young and middle-aged adults. The results call for greater awareness of tinnitus as a potential harbinger of future dementia in this population.

Potential Virus Involvement in Alzheimer's Disease: Results from a Phase IIa Trial Evaluating Apovir, an Antiviral Drug Combination

Background:

Accumulating data suggest infectious agents are involved in Alzheimer’s disease (AD). The two primary aims of this trial were to assess safety and efficacy of an antiviral drug combination on AD progression.

Objective:

The trial evaluated whether Apovir, a combination of two antiviral agents, pleconaril (active on enteroviruses) and ribavirin (active on several viruses), could slow AD progression.

Methods:

Sixty-nine patients 60–85 years were treated with Apovir or placebo for 9 months and followed until 12 months after end of treatment. Cognitive tests, safety, biomarkers, drug plasma, and cerebrospinal fluid concentrations were assessed.

Results:

The tolerability of Apovir was compromised as demonstrated by the large drop-out rate and increased frequency and severity of adverse events. The primary endpoint, demonstrating a difference in change from baseline to 9 months between groups in ADAS-cog total score, was not met (p = 0.1809). However, there were observations indicating potential effects on both ADAS-cog and CDR-SB but these effects need to be verified. Also, there was a decrease in cerebrospinal fluid amyloid-β in Apovir at 9 months (p = 0.0330) but no change in placebo.

Conclusion:

This was the first randomized, placebo controlled clinical trial exploring antiviral treatment on AD progression. The trial is considered inconclusive due to the large drop-out rate. New trials are needed to verify if the indications of effect observed can be confirmed and which component(s) in Apovir contributed to such effects. Pleconaril alone may be studied to improve the tolerability and to verify if enterovirus is involved in the disease process.

Modifiable, Non-Modifiable, and Clinical Factors Associated with Progression of Alzheimer's Disease

There is an extensive literature relating to factors associated with the development of Alzheimer's disease (AD), but less is known about factors which may contribute to its progression. This review examined the literature with regard to 15 factors which were suggested by PubMed search to be positively associated with the cognitive and/or neuropathological progression of AD. The factors were grouped as potentially modifiable (vascular risk factors, comorbidities, malnutrition, educational level, inflammation, and oxidative stress), non-modifiable (age at clinical onset, family history of dementia, gender, Apolipoprotein E ɛ4, genetic variants, and altered gene regulation), and clinical (baseline cognitive level, neuropsychiatric symptoms, and extrapyramidal signs). Although conflicting results were found for the majority of factors, a positive association was found in nearly all studies which investigated the relationship of six factors to AD progression: malnutrition, genetic variants, altered gene regulation, baseline cognitive level, neuropsychiatric symptoms, and extrapyramidal signs. Whether these or other factors which have been suggested to be associated with AD progression actually influence the rate of decline of AD patients is unclear. Therapeutic approaches which include addressing of modifiable factors associated with AD progression should be considered.

Frontotemporal dementia and COVID-19: Hypothesis generation and roadmap for future research

The COVID-19 pandemic has caused tremendous suffering for patients with dementia and their caregivers. We conducted a survey to study the impact of the pandemic on patients with mild frontotemporal dementia (FTD). Our preliminary findings demonstrate that patients with FTD have significant worsening in behavior and social cognition, as well as suffer greater negative consequences from disruption to health-care services compared to patients with AD. The reduced ability to cope with sudden changes to social environments places patients with FTD at increased vulnerability to COVID-19 infection as well as to poorer clinical and social outcomes. Caregivers of FTD patients also demonstrate high burden during crisis situations. A proportion of patients with FTD benefitted from use of web-based interactive platforms. In this article, we outline the priority areas for research as well as a roadmap for future collaborative research to ensure greatest benefit for patients with FTD and their caregivers.

Screening of Cognitive Changes in Adults with Intellectual Disabilities: A Systematic Review

Background and Aims: Screening and assessment of cognitive changes in adults with Intellectual Disabilities (ID), mainly Down Syndrome (DS), is crucial to offer appropriate services to their needs. We present a systematic review of the existing instruments assessing dementia, aiming to support researchers and clinicians’ best practice. Methods: Searches were carried out in the databases Web of Science; PubMed; PsycINFO in March 2019 and updated in October 2020. Studies were selected and examined if they: (1) focused on assessing age-related cognitive changes in persons with ID; (2) included adults and/or older adults; (3) included scales and batteries for cognitive assessment. Results: Forty-eight cross-sectional studies and twenty-seven longitudinal studies were selected representing a total sample of 6451 participants (4650 DS and 1801 with other ID). In those studies, we found 39 scales, questionnaires, and inventories, and 13 batteries for assessing cognitive and behavioural changes in adults with DS and other ID. Conclusion: The most used instrument completed by an informant or carer was the Dementia Questionnaire for Learning Disabilities (DLD), and its previous versions. We discuss the strengths and limitations of the instruments and outline recommendations for future use.

Genetic Analysis of Chinese Patients with Early-Onset Dementia Using Next-Generation Sequencing

Objective

Early-onset dementia (EOD) is a relatively uncommon form of dementia that afflicts people before age 65. Only a few studies analyzing the genetics of EOD have been performed in the Chinese Han population. Diagnosing EOD remains a challenge due to the diverse genetic and clinical heterogeneity of these diseases. The aim of this study was to investigate the genetic spectrum and clinical features of Chinese patients with EOD.

Materials and Methods

A total of 49 EOD patients were recruited. Targeted next-generation (NGS) analyses were performed to screen for all of the known genes associated with dementia. Possible pathogenic variants were confirmed by performing Sanger sequencing. The genetic spectrum and clinical features of the EOD patients were analyzed.

Results

Seven previously reported pathogenic variants (p.I213T and p.W165C in PSEN1; p.D678N in APP; c.1349_1352del in TBK1; p.P301L and p.R406W in MAPT; p.R110C in NOTCH3) and two novel variants of uncertain significance (p.P436L in PSEN2; c.239-11G>A in TARDBP) were identified.

Conclusion

Our study demonstrated the genetic spectrum and clinical features of EOD patients, and it reveals that genetic testing of known causal genes in EOD patients can help to make a precise diagnosis.

Neuropsychological Similarities and Differences Between Amnestic Alzheimer's Disease and its Non-Amnestic Variants

BACKGROUND

The neuropsychological recognition of early-onset Alzheimer's disease (AD) can be difficult because of non-amnestic variants such as logopenic variant primary progressive aphasia (lvPPA) and posterior cortical atrophy (PCA).

OBJECTIVE

This study evaluated the similarities and differences between typical amnestic AD (tAD) and lvPPA and PCA on a screening neuropsychological battery.

METHODS

We enrolled 51 patients meeting NIA-AA criteria for biomarker-supported AD (amnestic or non-amnestic) and having an age of onset of <65 years of age. Based on additional recommended clinical criteria for lvPPA and PCA, the early-onset AD patients were divided into three groups (28 tAD, 9 lvPPA, 14 PCA) of comparable age and dementia severity. We then analyzed their profiles on a focused, screening neuropsychological battery for early-onset AD.

RESULTS

In addition to greater variance on the Mini-Mental State Examination, the lvPPA and PCA variants had episodic memory impairment that did not significantly differ from the memory impairment in the tAD patients. Despite differences on language and visuospatial tasks, they did not significantly distinguish the lvPPA and PCA from tAD. The lvPPA group, however, was distinguishable by worse performance on measures reflecting working memory (digit span forward, memory registration).

CONCLUSIONS

On neuropsychological screening, all clinical early-onset AD subtypes may have memory impairments. Screening batteries for early-onset AD should also include measures of working memory, which is disproportionately decreased in lvPPA.

A novel SNCA E83Q mutation in a case of dementia with Lewy bodies and atypical frontotemporal lobar degeneration

In this case report, we discuss a patient presenting with parkinsonism followed by a non-amnestic dementia with aphasic clinical features, as well as frontal dysexecutive syndrome. There was a family history of dementia with an autopsy diagnosis of "Pick's disease" in the proband's father. Neuroimaging of the patient revealed focal and severe temporal lobe and lesser frontoparietal lobe atrophy. At autopsy, there was severe frontotemporal lobar degeneration. Histologic evaluation revealed an absence of tau or transactivation response DNA-binding protein of 43 kDa (TDP) pathology but rather severe Lewy body deposition in the affected cortices. Genetic phenotyping revealed a novel missense mutation (p.E83Q) in exon 4 of the gene encoding α-synuclein (SNCA). This case study presents a patient with a novel SNCA E83Q mutation associated with widespread Lewy body pathology with prominent severe atrophy of the frontotemporal lobes and corresponding cognitive impairment.

A multiomics approach to heterogeneity in Alzheimer's disease: focused review and roadmap

Aetiological and clinical heterogeneity is increasingly recognized as a common characteristic of Alzheimer's disease and related dementias. This heterogeneity complicates diagnosis, treatment, and the design and testing of new drugs. An important line of research is discovery of multimodal biomarkers that will facilitate the targeting of subpopulations with homogeneous pathophysiological signatures. High-throughput 'omics' are unbiased data-driven techniques that probe the complex aetiology of Alzheimer's disease from multiple levels (e.g. network, cellular, and molecular) and thereby account for pathophysiological heterogeneity in clinical populations. This review focuses on data reduction analyses that identify complementary disease-relevant perturbations for three omics techniques: neuroimaging-based subtypes, metabolomics-derived metabolite panels, and genomics-related polygenic risk scores. Neuroimaging can track accrued neurodegeneration and other sources of network impairments, metabolomics provides a global small-molecule snapshot that is sensitive to ongoing pathological processes, and genomics characterizes relatively invariant genetic risk factors representing key pathways associated with Alzheimer's disease. Following this focused review, we present a roadmap for assembling these multiomics measurements into a diagnostic tool highly predictive of individual clinical trajectories, to further the goal of personalized medicine in Alzheimer's disease.

Early-Onset Dementia in War Veterans: Brain Polypathology and Clinicopathologic Complexity

The neuropathology associated with cognitive decline in military personnel exposed to traumatic brain injury (TBI) and chronic stress is incompletely understood. Few studies have examined clinicopathologic correlations between phosphorylated-tau neurofibrillary tangles, β-amyloid neuritic plaques, neuroinflammation, or white matter (WM) lesions, and neuropsychiatric disorders in veterans. We describe clinicopathologic findings in 4 military veterans with early-onset dementia (EOD) who had varying histories of blunt- and blast-TBI, cognitive decline, behavioral abnormalities, post-traumatic stress disorder, suicidal ideation, and suicide. We found that pathologic lesions in these military-EOD cases could not be categorized as classic Alzheimer's disease (AD), chronic traumatic encephalopathy, traumatic axonal injury, or other well-characterized clinicopathologic entities. Rather, we observed a mixture of polypathology with unusual patterns compared with pathologies found in AD or other dementias. Also, ultrahigh resolution ex vivo MRI in 2 of these 4 brains revealed unusual patterns of periventricular WM injury. These findings suggest that military-EOD cases are associated with atypical combinations of brain lesions and distribution rarely seen in nonmilitary populations. Future prospective studies that acquire neuropsychiatric data before and after deployments, as well as genetic and environmental exposure data, are needed to further elucidate clinicopathologic correlations in military-EOD.

Misfolded proteins as a therapeutic target in Alzheimer's disease

For decades, Alzheimer's Disease (AD) was defined as a disorder of protein misfolding and aggregation. In particular, the extracellular peptide fragment: amyloid-β (Aβ), and the intracellular microtubule-associated protein: tau, were thought to initiate a neurodegenerative cascade which culminated in AD's progressive loss of memory and executive function. As such, both proteins became the focus of intense scrutiny, and served as the principal pathogenic target for hundreds of clinical trials. However, with varying efficacy, none of these investigations produced a disease-modifying therapy - offering patients with AD little recourse aside from transient, symptomatic medications. The near universal failure of clinical trials is unprecedented for a major research discipline. In part, this has motivated an increasing skepticism of the relevance of protein misfolding to AD's etiology. Several recent observations, principally the presence of significant protein pathologies in non-demented seniors, have lent credence to an apparent cursory role for Aβ and tau. Herein, we review both Aβ and tau, examining the processes from their biosynthesis to their pathogenesis and evaluate their vulnerability to medicinal intervention. We further attempt to reconcile the apparent failure of trials with the potential these targets hold. Ultimately, we seek to answer if protein misfolding is a viable platform in the pursuit of a disease-arresting strategy for AD.

Metabolic Syndrome and cognitive decline in the elderly: A systematic review

Background

Metabolic Syndrome (MetS) refers to a cluster of metabolic disturbances which is associated with increased risk for vascular and degenerative conditions in general population. Although the relationship between vascular risk factors and dementia is undisputable, additional hazard for cognitive decline in older population with concurrent metabolic disorders still waits to be demonstrated. The present review aims to analyze data on MetS and risk for cognitive decline in elderly persons.

Methods

Database searches were performed in Medline, ISI and PsycINFO for articles assessing cognitive performances of older subjects with MetS.

Results

Of a total of 505 studies, 25 were selected for the review. Risk of selection biases was identified in all the studies. Although all articles followed recognized diagnostic recommendations for MetS, minor criteria modifications were detected in most of them. Hyperglycemia was consistently associated with impaired cognitive performances in older individuals, but the role of MetS for cognitive decline and for the onset of dementia showed heterogeneous results.

Discussion

Current available data in the literature concerning the impact of MetS on the cognition of older population is inconclusive and based on inconsistent evidence. Differential effects of individual MetS components and factors associated with the age of the sample may have accounted for divergent findings among articles, but larger and higher quality studies in this field are still needed.

A prospective 20-year longitudinal follow-up of dementia in persons with Down syndrome

GOAL

To examine dementia characteristics, age at onset and associated co-morbidities in persons with Down syndrome.

METHOD

A total of 77 people with Down syndrome aged 35 years and older were followed up from 1996 to 2015. The diagnosis of dementia was established using the modified ICD 10 Criteria and a combination of objective and informant-based tests. Cognitive tests included the Test for Severe Impairment and the Down Syndrome Mental Status Examination; adaptive behaviour was measured using the Daily Living Skills Questionnaire, and data from the Dementia Questionnaire for People with Intellectual Disabilities have been available since 2005.

RESULTS

Over the 20-year period, 97.4% (75 of 77) persons developed dementia with a mean age of dementia diagnosis of 55 years (SD = 7.1, median = 56 years). Clinical dementia was associated with cognitive and function decline and seizure activity. Risk for dementia increased from 23% in those aged 50 years to 80% in those aged 65 years and above. There were no differences by level of ID.

CONCLUSION

The previously reported high risk levels for dementia among people with Down syndrome were confirmed in this data as was the relationship with late onset epilepsy. The value of the instruments utilised in tracking decline and helping to confirm diagnosis is further highlighted.

Psychosocial impact of early onset dementia among caregivers

Introduction: There is growing recognition of early onset dementia (EOD) as a significant clinical and social problem because of its effects on physical and mental health of people with dementia (PWD) and their caregivers. Objective: To analyze the psychosocial impact of EOD in family caregivers. Methods: The study design was qualitative. Nine EOD caregivers (7 women) were recruited at a service for Alzheimer's disease and assessed using semi-structured interviews. Interpretative phenomenological analysis was used to analyze caregivers' reports. Results: Five themes emerged from the narratives: psychological and emotional impact; physical impact; financial and professional impact; social impact and need for support services. The majority of the caregivers of people with EOD perceived their emotional wellbeing as poor or extremely poor. Carers reported poor physical health, which tends to be longer-lasting than mental health problems. Two caregivers had to retire after the disclosure of the dementia diagnosis, and seven reduced their work loads because they had to look after PWD. Preserving the abilities of PWD is essential to maintain their self-esteem, dignity and sense of utility. For the caregivers, interventions and stimulating activities make PWD feel worthwhile and contribute to improving life. Conclusion: The caregivers of people with EOD assume the role of caregiver prematurely and need to balance this activity with other responsibilities. There is a need for more studies of EOD in order to improve understanding of the impact of this disease and to enable development of adequate services for PWD and their caregivers.