Young-onset Dementia Patients Research Articles

Young‐onset dementia in memory clinics in the Netherlands: PRECODE‐GP

AbstractBackgroundThe disease trajectory of patients with young onset dementia differs from older patients, as do healthcare requirements. To improve specialized care, more insight in young onset dementia is crucial. The aim of PRECODE‐GP is therefore 1) to conduct an (annual) inventory of the diagnostic workup in all memory clinics in the Netherlands, and 2) to set up a prospective nationwide database including newly diagnosed younger patients with dementia.MethodsPRECODE‐GP is part of the PRECODE project, a collaboration between four Dutch Alzheimer centers, Knowledgecenter Dementia at Young Age, Nivel and Alzheimer Nederland. Governance is embedded in the Dutch Memory Clinic Network. Memory clinics are asked annually to fill out a survey on their current diagnostic workup. Eligible patients (<70 years; any type of dementia) are identified by local specialists and recruited via an informed consent procedure providing consent for future linkage to other datasets. Demographics, test results and (etiological) diagnosis are collected in an online database.ResultsPRECODE‐GP was initiated in July 2019 and has been approved in 36 memory clinics, approval procedure is ongoing in additional 10 clinics. Based on the annual survey (filled out by 21 clinics), standard imaging of the brain occurs in almost half of memory clinics and neuropsychological examination in one third. CSF is performed when deemed necessary by the clinician. A median 250(141‐396) new patients visited the memory clinics yearly, of whom 111(74‐180)(48%) were diagnosed with dementia and 12(4‐36)(6%) were <70 years. To date, 201 young onset dementia patients (age 62±8, 51% female, MMSE 22±5) are included in our prospective database, diagnosed with 140(69%) Alzheimer’s dementia (AD), 29(14%) frontotemporal dementia (FTD), 14(7%) dementia with Lewy Bodies (DLB) and 18(9%) other dementia types. Patients with FTD were youngest (61±6 years), subjects with DLB were most often male (79%), in AD MMSE was lowest (21±5).ConclusionWe took the first step to include patients with young onset dementia via all Dutch memory clinics. As a next step, we plan to link data to existing registries, to gain valuable knowledge on disease trajectories. All needed to improve quality of life for patients with young onset dementia.

The Impact of Amyloid PET Disclosure on Quality of Life in Patients With Young Onset Dementia.

The impact of amyloid positron emission tomography (PET) imaging on patient health outcomes for individuals with dementia is unknown. In the present study, we explored the association between diagnostic outcome and clinician's level of certainty with quality of life (QoL) after [18F]flutemetamol PET results were disclosed in young onset dementia patients in a memory clinic cohort. In 154 patients suspected of dementia, QoL was measured before and after [18F]flutemetamol PET results were disclosed. Multiple regression analyses were conducted with (changed) general and disease-specific QoL measures as dependent factors [QoL-Alzheimer disease (AD) and EQ-5D Dutch tariff] and etiological diagnosis and clinician's certainty as independent factors. (Change in) diagnosis of AD was associated to QOL in 2 of the 4 analyses (utility-based QoL β=0.15, P=0.010; disease-specific QoL β=2.0, P=0.037). Diagnostic certainty was associated to QOL in 1 of the 4 analyses (generic QoL β=0.002, P=0.028). The diverse results in this explorative analysis do not reflect a univocal association between diagnosis, certainty, and QoL. Nevertheless, this result could be interpreted as a possible potential for advanced diagnostic technologies for AD, which requires confirmation in future research.

Patients with young-onset dementia in an older people's mental health service.

Currently, no separate service exists for patients with young-onset dementia in Cambridgeshire. These patients are managed together with late-onset dementia patients within old age psychiatry services. To inform service design, we sought to characterise young-onset dementia patients in our population. We first analysed service-level data and supplemented this with a detailed case review of 90 patients. Young-onset dementia remains a relatively rare condition. Only a small proportion of those referred for assessment receive a diagnosis of dementia. Data collected on presenting complaints, comorbidities, medication and Health of the Nation Outcome Scales scores associated young-onset dementia with a greater incidence of depression than late-onset dementia. Outcomes in the two groups did not appear to differ. The data presented here do not suggest a need to create a separate service. Practitioners should be aware of the increased incidence of depression observed in this group.

Quality of Life Assessments in Individuals With Young-Onset Dementia and Their Caregivers.

Background:Quality of life (QoL) has seldom been investigated or explicitly measured in young-onset dementia (YoD). The aims of this study were (1) to investigate and compare QoL self- and proxy reports in a sample of YoD patients and caregivers using different conceptual assessments of QoL and (2) to examine the relationship between caregiver QoL and both burden and mental health.Methods:There were 52 participants (26 YoD patient–caregiver dyads). The design was cross-sectional and part of a larger longitudinal prospective cohort study of YoD patients and caregivers. Primary measures included generic QoL (World Health Organization Quality of Life–short version [WHOQOL-BREF]), dementia-specific QoL (Quality of Life in Alzheimer’s Disease Scale [QoL-AD]), health-related QoL (EQ5D), and a single-item QoL measure. Secondary measures included caregiver burden (Zarit Burden Index), mental health (Hospital Anxiety and Depression Scale), and dementia severity (Clinical Dementia Rating).Results:Patient QoL self-reports were higher than caregiver proxy reports on the QoL-AD (P = .001). Patient QoL self-reports for the WHOQOL-BREF (P < .01) and single-item QoL (P < .05) measure were significantly higher than caregiver self-reports. Dementia severity had no relationship with QoL self-reports. Caregiver burden, anxiety, and depression were negatively correlated with QoL when measured using a generic and single-item measure, but not with the health-related measure.Discussion:Patients and caregivers show a disparity in QoL reports, with patients tending to report higher QoL. Caregiver burden, anxiety, and depression should be areas targeted for interventions when supporting caregivers.

Characteristics of Young-Onset and Late-Onset Dementia Patients at a Remote Memory Clinic

Young-onset dementia (YOD) is defined as the onset of dementia symptoms before the age of 65 years and accounts for 2-8% of dementia. YOD patients and their caregivers face unique challenges in diagnosis and management. We aimed to compare the characteristics of rural YOD and late-onset dementia (LOD) patients at a rural and remote memory clinic in Western Canada. A total of 333 consecutive patients (YOD = 61, LOD = 272) at a rural and remote memory clinic between March 2004 and July 2016 were included in this study. Each patient had neuropsychological assessment. Health, mood, function, behaviour and social factors were also measured. Both groups were compared using χ2 tests and independent sample tests. YOD patients were more likely to be married, employed, current smokers and highly educated. They reported fewer cognitive symptoms, but had more depressive symptoms. YOD patients were less likely to live alone and use homecare services. YOD caregivers were also more likely to be a spouse and had higher levels of distress than LOD caregivers. Both YOD and LOD patient groups were equally likely to have a driver's licence. Our findings indicate YOD and LOD patients have distinct characteristics and services must be modified to better meet YOD patient needs. In particular, the use of homecare services and caregiver support may alleviate the higher levels of distress found in YOD patients and their caregivers. Additional research should be directed to addressing YOD patient depression, caregiver distress and barriers to services.

P.003 Differences between younger and older dementia patients at a rural and remote memory clinic

Background: Young-onset dementia (YOD) patients and their caregivers face unique challenges in diagnosis and management. We aimed to compare the characteristics of rural YOD and late-onset dementia (LOD) patients. Methods: A total of 333 consecutive patients (YOD=61, LOD=272) at a rural and remote memory clinic between March 2004 and July 2016 were included in this study. Each patient had neuropsychological assessment. Health, mood, function, behaviour, and social factors were also measured. Both groups were compared using χ2 tests and independent sample tests. Results: YOD patients were more likely to be married, employed, current smokers, and highly educated. They reported fewer cognitive symptoms, but had more depressive symptoms. YOD patients were less likely to live alone and use homecare services. YOD caregivers were also more likely to be a spouse and had higher levels of distress than LOD caregivers. Conclusions: Our findings indicate YOD and LOD patients have distinct characteristics and services must be modified to better meet YOD patient needs. In particular, the use of homecare services and caregiver support may alleviate the higher levels of distress found in YOD patients and their caregivers. Additional research should be directed to addressing YOD patient depression, caregiver distress, and barriers to services.

Understanding Important Issues in Young-Onset Dementia Care: the Perspective of Healthcare Professionals

Psychosocial research on the lived experiences of young-onset dementia patients and caregivers has identified salient issues about their care, however, views on care from the perspective of young-onset dementia healthcare professionals is less well known. The aim of this study was to investigate and identify important issues in young-onset dementia care provision from a healthcare provider perspective. The design was an exploratory qualitative interview study. In-depth semistructured interviews were conducted with healthcare professionals with clinical expertise in young-onset dementia drawn from medicine, nursing and allied health. Thematic analysis was applied to interview transcripts to identify themes representing important underlying issues in care across the dementia clinical pathway (i.e., prediagnosis, diagnosis and postdiagnosis). In prediagnosis, it is important for healthcare professionals to recognize symptoms as organic and degenerative and more than psychological, and to refer patients to an appropriate clinical facility for assessment. During diagnosis, it may be challenging to determine dementia, and methods are employed to manage diagnostic uncertainty. Following diagnosis, optimizing routine clinical care is important and can include the provision of practical informational guidance, empathic concern and psychoeducational support. Meeting service-user requirements in the community is an important aspect of care, and may be facilitated by the involvement of clinical nurse specialists. The findings are presented as a paradigm for holistic young-onset dementia care. The paradigm offers a framework for contemplating and evaluating the criteria and quality of young-onset dementia care.

DEVELOPMENT AND EVALUATION OF MOBILE APPLICATION FOR PEOPLE WITH YOUNG-ONSET DEMENTIA AND THEIR CARERS

Young Onset Dementia (YOD) defined as the onset of dementia before the age of 65 years is increasingly recognized as an important clinical and social problem with devastating consequences for the patients and those who care for them. YOD is less common than late onset dementia and accessing age appropriate information and services for young people with YOD is limited. Post-diagnostic support for patient and carers to help adjust to the reality of what this may mean in terms of the future is important. We aimed to develop a YOD app which would provide information and support for YOD patients and their carers; and to obtain feedback via focus groups with patient and carers. YOD app was developed, collaboration between Memory Services, National Health Service Trust, NHS Health informatics Service and Common Point. Focus groups with different patient and carers were conducted for feedback on the app which was used to improvise the app before its publication. After undergoing styling, content checking and video-editing the app was published on Apple Store and Google Play Store (for android devices) for free download with search term- YOD dementia (please download to view the app). YOD app developed is used by people with dementia and their carers to access information and provide guidance for self –management with appropriate knowledge and more importantly signposts them to an array of services and organisations that provide specialised support locally, regionally and Nationally. The app enables them to access information from a wide range of sources, in one place, in a timely fashion, at the point when they are ready to this information. It also has fact sheets and links to various websites with more information. The app has been downloaded locally and globally (analytics will be presented).

YOUNG-ONSET DEMENTIA IN A SOUTHEAST ASIAN POPULATION FROM SINGAPORE: CLINICAL AND BIOMARKER CHARACTERIZATION

Patients with Young onset dementia (YOD) are less likely to have mixed pathology, have a higher genetic predisposition and thus detailed characterization of this cohort may offer an opportunity for biomarker development and discovery of novel drug interventions. Existing Asian YOD cohorts are largely from Japan and thus little is known about the clinical and biomarker profile of YOD in Southeast Asia. We present the clinical and biomarker characteristics of Southeast Asian YOD patients from multiethnic Singapore. Patients were recruited from the National Neuroscience Institute beginning January 2012. Beginning July 2015, additional biomarker data including volumetric MRI, genetics and cerebrospinal fluid (CSF) were collected. Volumetric MRI was performed on a 3T Siemens machine. CSF Amyloidβ, total tau and phosphor-tau were performed using ELISA techniques. Diagnosis of dementia was made at consensus meetings comprising of cognitive neurologists, neuroradiologists, psychologists and dementia nurses. Alzheimer's disease (AD) was diagnosed based on the NIA-AA criteria, Vascular Dementia (VaD) based on the NINDS-ADRDA criteria and Frontotemporal Dementia (FTD) based on the Rascovsky criteria. MCI was diagnosed based on the Petersen's criteria. A total 309 patients were recruited between 2012 and Dec 2016. There were 250 patients with dementia (N, AD=145, VaD=30, FTD=48) and 59 patients with MCI. Mean (SD) age of onset for AD, VaD and FTD was 56.77 (5.06), 56.84 (5.61) and 56.60 (5.32) respectively. Family history of YOD among first degree relatives were present in 28.7% of AD, 10.0% of VAD and 22.9% of FTD. Of the 143 patients with Young Onset AD, 90.9% had amnestic AD, 2.1 % had behavioral variant AD and 1.4% had logopenic variant and 5.6% had Posterior Cortical Atrophy type of AD. 39.0% consented for CSF analyses. Further analyses with clinical, neuropsychological, volumetric MRI and CSF findings are on-going. This is the first report of YOD in Southeast Asians. AD continues to be the major subtype of YOD. Non-amnestic AD is present in about 10% and 29% of Young AD have a positive family history. Greater awareness on the clinical presentation of YOD among Southeast Asians is needed for earlier diagnosis and timely intervention.

Spotting early onset dementia.

How best can people aged under 65 with dementia be supported? Pras Ramluggan and Emakpor Ogo write in Mental Health Practice about the unique needs of young onset dementia patients and their families. While there are strategies and care delivery for dementia patients, these are not specifically targeted to the demographic profile of young onset dementia patients. The piece discusses the good practice by the young people with dementia service in Cambridgeshire, which aims to empower service users by restoring confidence and self-esteem following diagnosis.

RHAPSODY - Internet-based support for caregivers of people with young onset dementia: program design and methods of a pilot study.

Young Onset Dementia (YOD), defined by first symptoms of cognitive or behavioral decline occurring before the age of 65 years, is relatively rare compared to dementia of later onset, but it is associated with diagnostic difficulty and heavy burden on affected individuals and their informal carers. Existing health and social care structures rarely meet the needs of YOD patients. Internet-based interventions are a novel format of delivering health-related education, counseling, and support to this vulnerable yet underserved group. The RHAPSODY (Research to Assess Policies and Strategies for Dementia in the Young) project is a European initiative to improve care for people with YOD by providing an internet-based information and skill-building program for family carers. The e-learning program focuses on managing problem behaviors, dealing with role change, obtaining support, and looking after oneself. It will be evaluated in a pilot study in three countries using a randomized unblinded design with a wait-list control group. Participants will be informal carers of people with dementia in Alzheimer's disease or behavioral-variant Frontotemporal degeneration with an onset before the age of 65 years. The primary outcome will be caregiving self-efficacy after 6 weeks of program use. As secondary outcomes, caregivers' stress and burden, carer health-related quality of life, caring-related knowledge, patient problem behaviors, and user satisfaction will be assessed. Program utilization will be monitored and a health-economic evaluation will also be performed. The RHAPSODY project will add to the evidence on the potential and limitations of a conveniently accessible, user-friendly, and comprehensive internet-based intervention as an alternative for traditional forms of counseling and support in healthcare, aiming to optimize care and support for people with YOD and their informal caregivers.

Young onset demented patients in French cognitive-behavioral specialized units.

The number of patients with young onset dementia (YOD) (first symptoms beginning before the age of 60 years) is estimated around 5,000 in France. On account of the usual severity of behavioral symptoms in these patients, the need for cognitive-behavioral specialized unit (UCC) is expected. To determine the number and characteristics of YOD patients cared for in UCC in France during the year 2013. A specific questionnaire was sent to the 84 French UCC. The questionnaire was completed by 55 UCC (65%), whose 33 received 179 YOD patients. The diagnosis was Alzheimer's disease in 50% of the cases and frontotemporal dementia in 30%. The main reasons for the hospitalization in UCC were the severity of behavioral symptoms in 86% of cases, the need to alleviate the caregiver burden in 31% and the waiting for a place in a nursing home in 23%. Mean duration of hospitalization was 40.4 ± 20.5 days. At the end of hospitalization 51% of the patients returned to their original living accomodation and 39% entered into a nursing home. The main reason of YOD patients hospitalization reject was the care team's fear in the UCC without experience. The severity of the behavioral troubles was the major issue while the necessary ethical reflection raised by the YOD patients management was a positive aspect. The teams rated how ready do they feel about taking care of YOD patients on a scale from 0 to 100, the median was 35. The welcoming of YOD patients in UCC is necessary, however the severity of the behavioral troubles and the care teams fear prompt to set up specific education and to increase of the number of staff for YOD patients management.

Cost Related to Dementia in the Young and the Impact of Etiological Subtype on Cost.

Young onset dementia (YOD) presents in individuals who are economically productive and socially active. While the cost related to dementia in the elderly has been widely studied, the cost related to YOD is largely unknown. To study the economic burden of community dwelling YOD in relation to late onset dementia (LOD) and cost of YOD based on etiology. In this prospective cross-sectional study of 255 patients attending a tertiary neurology center, data on economic burden, clinical features, and caregiver burden were collected using structured financial questionnaire, standard cognitive and neuropsychiatric measures, and Zarit caregiver burden scale. Cost components were grouped into those relating to direct medical costs, direct non-medical costs, and those related to indirect costs. Cost was also categorized based on etiology of YOD. The mean age at symptom onset in the YOD and LOD cohort was 57.0 (SD 5.1) and 75.0 (SD 5.9) years, respectively. The median annual cost for patients with YOD was almost twice that of LOD (USD 15,815 versus USD 8,396). Indirect cost contributed heavily to cost related to YOD. Even when grouped by dementia etiology, YOD patients with Alzheimer's disease, frontotemporal dementia (FTD), and vascular dementia had higher cost compared to their elderly counterparts. Young onset FTD had the highest cost. 43.2% of YOD reported loss of employment due to dementia, which was significantly higher than that in LOD (2.4%). Patients with YOD have a high economic burden. Young patients with FTD have the highest cost followed by vascular dementia and Alzheimer's disease.

Characteristics of institutionalized young onset dementia patients--the BEYOnD study.

People with Young Onset Dementia (YOD) have specific needs for care. These people eventually require institutional care, usually delivered by institutions designed for the elderly. The Dutch network of care organizations delivering specialized YOD care offers a unique opportunity to obtain more knowledge of this special population. Our cross-sectional study collected data from 230 people with YOD in eight care homes providing YOD specialized care. Data collected: demographic data, disease duration, dementia subtype, comorbidity, dementia severity (Global Deterioration Scale - GDS), neuropsychiatric symptoms (NPS; Neuropsychiatric Inventory - NPI, Cohen Mansfield Agitation Inventory - CMAI), disease awareness (Guidelines for the Rating of Awareness Deficits - GRAD), need for assistance (hierarchic Activities of Daily Living (ADL) scale - Resident Assessment Instrument - Minimum Data Set (RAI-MDS)). The mean age of the residents with YOD in care homes was 60 years and 53% of them were men. There is a large variety of etiologic diagnoses underlying the dementia. Dementia severity was very mild to mild in 18%, moderate in 25%, and severe or very severe in 58% of the participants. The prevalence of NPS was high with 90% exhibiting one or more clinically relevant NPS. Comorbidity was present in more than three quarters of the participants, most frequently psychiatric disorders. The institutionalized YOD population is heterogeneous. NPS occur in almost all institutionalized people with YOD, and frequency and severity of NPS are higher than in late onset dementia (LOD) and community-dwelling YOD patients. Care should be delivered in settings accommodating a mixed male and female population, with appropriate, meaningful activities for all individuals. Further research is needed on NPS in YOD, to enhance quality of life and work in specialized YOD-care.

Prevalence and correlates of psychotropic drug use in community-dwelling people with young-onset dementia: the NeedYD-study

Young-onset dementia (YOD) is defined as dementia that develops before the age of 65 years. The prevalence and type of neuropsychiatric symptoms (NPS) in YOD differ from patients with late onset dementia. NPS in dementia patients are often treated with psychotropic drugs. The aim of this study was to investigate psychotropic drug use (PDU) in Dutch community-dwelling YOD patients and the association between age, gender, dementia etiology and severity, symptoms of depression, disease awareness, unmet needs, and type of NPS. Psychotropic drug use in 196 YOD patients was registered. Drugs were categorized according to the Anatomical Therapeutical Chemical classification. The association between age, gender, dementia type, dementia stage, type of NPS, depressive symptoms, disease awareness, and amount of unmet needs on total PDU was analyzed using binomial logistic regression analysis. Fifty-two percent of the patients were prescribed at least one psychotropic drug; 36.2% of patients used one drug, and 12.2% used two different drugs. Antidepressants (36.2%) and antipsychotic drugs (17.3%) were the most frequently prescribed psychotropic drugs. Anti-dementia drugs were prescribed in 51.5% of the patients. Increasing age and moderate to severe depressive symptoms were positively associated with the total use of psychotropic drugs. Community-dwelling YOD patients have a high prevalence of PDU. More research is needed to study the association between unmet needs, NPS, and PDU, and psychosocial interventions have to be developed to limit the use of psychotropic drugs in YOD.

Unmet Needs and Health-Related Quality of Life in Young-Onset Dementia

Young-onset dementia (YOD) causes specific challenges and issues that are likely to affect health-related quality of life (HRQOL). This study explored patient and caregiver HRQOL and its association with unmet needs in YOD. Across-sectional design was used to study 215 community-dwelling YOD patients and their primary caregivers. Multiple linear regression analyses were performed to determine the relationship between unmet needs assessed with the Camberwell Assessment of Need for the Elderly scale and patient and caregiver HRQOL, controlling for other variables such as demographic characteristics, patient functional status, neuropsychiatric symptoms, and caregiver sense of competence. Patient HRQOL was not associated with unmet needs. However, we found that the unmet needs of both patient and caregiver were related to several domains of caregiver HRQOL. This study shows that patient and caregiver unmet needs are related to caregiver HRQOL in YOD. However, the relationship between HRQOL and unmet needs is complex. The assessment of unmet needs within the context of HRQOL seems to be an important prerequisite for personalizing care in YOD. Adjusting supportive services to match the individual needs and preferences of these young patients and their caregivers is likely to enhance their quality of life.

Alzheimer's disease and related disorders: specificity of young onset patients, including ethical aspects

The number of patients with young onset dementia (YOD) (that is before age 65) is estimated at 32,000 in France, and 5000 with onset dementia before 60 years. These patients differ from older ones by the greater number of rares causes (29%), heterogeneity of the presentation among the usual diseases, such as non-amnestic phenotypes of Alzheimer's disease, high frequency of frontal symptoms, and possible genetic origin. These aspects must be taken into account for the diagnosis, often more difficult than in older ones because patients have a little knowledge of the YOD, excepted in the genetics forms. YOD patients can still work or drive a car, and we should choose between the respect for autonomy and the security for the patient and their carers. YOD patients can be more often included in pharmacological trials because they have lower associated disorders. Individual non-pharmacological treatment should be priviledged because they don't easily accept collective activities with other patients over 60 years of age. Excepted for the very young patients (onset before 45), the survival is longer than in late onset dementia, with sometimes severe behavioral problems related to frontal syndrome. In France, the caregiving at home has been improved since the possibility for the YOD patients to receive a financial assistance reserved for the disabled patients, but admission to a nursing home before 60 is very difficult and increases the caregiver burden and perception of unfairness. There is a discrimination between young or older demented patients related to the great difficulty to meet the needs of younger patients, due to the rigidity of the medical and social systems. The presentation of a limited offer for the YOD patients must initiate reflections on our capacities to respect the autonomy and the dignity of the Alzheimer's patients regardless of age.

Les pathologies démentielles avant 65 ans. Expérience de la file active d’une consultation mémoire neurologique

ObjectiveThe aim of the study was to compare the profiles of patients with young (age≤65years) and late (age>65years) onset of dementia in a memory clinic of a Memory Referral Center in Lyons (France), for the year 2008. MethodsA total of 746 demented patients were evaluated using clinical, neuropsychological and imaging information. For each patient, diagnoses of the dementing disorder used clinical criteria at the first visit. We examined the distribution of patients diagnosis and differences in sex and education between the young-onset dementia (YOD) and the late-onset dementia (LOD) groups. ResultsFrom a total of 746 registered demented patients (300 men, 446 women), there were 91 patients (12.2%) with YOD (from 36.5 to 65years) and 655 patients with LOD (from 66 to 92years). Among the 91 YOD patients, the most frequent causes were Mild Cognitive Impairment (MCI) (18.7%), then Alzheimer's disease (AD), frontotemporal dementia and posterior cortical atrophy (14.3% each), followed by progressive aphasia (11.0%), dementia with Lewy bodies (DLD) (9.9%), semantic dementia (8.8%), other causes (3.3%), vascular dementia (2.2%), undetermined dementia (2.2%), AD+cerebrovascular disease (1.1%). Among the 655 LOD patients, AD was the most frequent cause of dementia (57.4%). Referred cases by a specialist doctor were 50.5% in the YOD group and 12.7% in the LOD group (P<0.0001). In the ACP group, 68.4% patients began before 65years. ConclusionThe number of YOD in our memory clinic was four-fold the number of expected patients in France. The characteristics of the Referral Center explain the high frequency of rare dementia such as progressive aphasia (5.2% of overall number), semantic dementia (3.6%) and posterior cortical atrophy (2.5%).