People with neuropsychiatric symptoms often experience delay in accurate diagnosis. Although cerebrospinal fluid neurofilament light (CSF NfL) shows promise in distinguishing neurodegenerative disorders (ND) from psychiatric disorders (PSY), its accuracy in a diagnostically challenging cohort longitudinally is unknown.

We collected longitudinal diagnostic information (mean = 36 months) from patients assessed at a neuropsychiatry service, categorising diagnoses as ND/mild cognitive impairment/other neurological disorders (ND/MCI/other) and PSY. We pre-specified NfL > 582 pg/mL as indicative of ND/MCI/other.

Diagnostic category changed from initial to final diagnosis for 23% (49/212) of patients. NfL predicted the final diagnostic category for 92% (22/24) of these and predicted final diagnostic category overall (ND/MCI/other vs. PSY) in 88% (187/212), compared to 77% (163/212) with clinical assessment alone.

CSF NfL improved diagnostic accuracy, with potential to have led to earlier, accurate diagnosis in a real-world setting using a pre-specified cut-off, adding weight to translation of NfL into clinical practice.

Vascular dementia (VD) is one of the more common types of dementia. Much is known about VD in older adults in terms of survival and associated risk factors, but comparatively less is known about VD in a younger population. This study aimed to investigate survival in people with young-onset VD (YO-VD) compared to those with late-onset VD (LO-VD) and to investigate predictors of mortality.

Retrospective file review from 1992 to 2014.

The inpatient unit of a tertiary neuropsychiatry service in Victoria, Australia.

Inpatients with a diagnosis of VD.

Mortality information was obtained from the Australian Institute of Health and Welfare. Clinical variables included age of onset, sex, vascular risk factors, structural neuroimaging, and Hachinksi scores. Statistical analyses used were Kaplan–Meier curves for median survival and Cox regression for predictors of mortality.

Eighty-four participants were included with few clinical differences between the LO-VD and YO-VD groups. Sixty-eight (81%) had died. Median survival was 9.9 years (95% confidence interval 7.9, 11.7), with those with LO-VD having significantly shorter survival compared to those with YO-VD (6.1 years and 12.8 years, respectively) and proportionally more with LO-VD had died (94.6%) compared to those with YO-VD (67.5%), χ2(1) = 9.16, p = 0.002. The only significant predictor of mortality was increasing age (p = 0.001).

While there were few clinical differences, and older age was the only factor associated with survival, further research into the effects of managing cardiovascular risk factors and their impact on survival are recommended.

Carer burden is common in younger-onset dementia (YOD), often due to the difficulty of navigating services often designed for older people with dementia. Compared to Alzheimer’s disease (AD), the burden is reported to be higher in behavioral variant frontotemporal dementia (bvFTD). However, there is little literature comparing carer burden specifically in YOD. This study hypothesized that carer burden in bvFTD would be higher than in AD.

Retrospective cross-sectional study.

Tertiary neuropsychiatry service in Victoria, Australia.

Patient-carer dyads with YOD.

We collected patient data, including behaviors using the Cambridge Behavioral Inventory-Revised (CBI-R). Carer burden was rated using the Zarit Burden Inventory-short version (ZBI-12). Descriptive statistics and Mann-Whitney U tests were used to analyze the data.

Carers reported high burden (ZBI-12 mean score = 17.2, SD = 10.5), with no significant difference in burden between younger-onset AD and bvFTD. CBI-R stereotypic and motor behaviors, CBI-R everyday skills, and total NUCOG scores differed between the two groups. There was no significant difference in the rest of the CBI-R subcategories, including the behavior-related domains.

Carers of YOD face high burden and are managing significant challenging behaviors. We found no difference in carer burden between younger-onset AD and bvFTD. This could be due to similarities in the two subtypes in terms of abnormal behavior, motivation, and self-care as measured on CBI-R, contrary to previous literature. Clinicians should screen for carer burden and associated factors including behavioral symptoms in YOD syndromes, as they may contribute to carer burden regardless of the type.

Younger-onset dementia (YOD) is a dementia of which symptom onset occurs at 65 years or less. There are approximately 27000 people in Australia with a YOD and the causes can range from Alzheimer’s dementia (AD), frontotemporal dementia (FTD), metabolic and genetic disorders. It is crucial to obtain a definitive diagnosis as soon as possible in order for appropriate treatment to take place and future planning. Previous research has reported 4-5 years to get a diagnosis (Draper et al. 2016) and factors associated with delay include younger age (van Vliet et al. 2013) and psychiatric comorbidity (Draper et al. 2016). We report on our experience of diagnostic delay.

This was a retrospective file review of 10 years of inpatients from Neuropsychiatry, Royal Melbourne Hospital, Australia. Neuropsychiatry is a tertiar service which provides assessment of people with cognitive, psychiatric, neurological and behavioural symptoms. Factors such as age of onset, number of services/specialists seen were extracted and analysed using multivariate regression.

Of the 306 individual patients who had a YOD, these were grouped into the major dementia groups (such as AD, FTD, Huntington’s disease, vascular dementia, alcohol-related dementia). The most commonly occurring dementia was AD (24.2%), followed by FTD (23%). There was an average of 3.7 years (SD=2.6), range 0.5-15 years, of delay to diagnosis. Cognitive impairment, as measured using the Neuropsychiatry Unit Cognitive Assessment (NUCOG) was moderate, with a mean score of 68.9 (SD=17.9). Within the groups of dementia, patients with Niemann-Pick type C (NPC) had the longest delay to diagnosis F(11,272)=3.677, p<0.0001, with 6.3 years delay. Age of symptom onset and number of specialists/services seen were the significant predictors of delay to diagnosis F(7, 212)=3.975, p<0.001, R211.6.

This was an eclectic group of people with YOD. The results of regression suggests that there are other factors which contribute to the delay, which are not just demographic related. Rarer disorders, such as NPC which present at an early age, and present with symptoms that are not cognitive in nature, can contribute to diagnostic delay.

While early diagnosis of younger-onset dementia (YOD) is crucial in terms of accessing appropriate services and future planning, diagnostic delays are common. This study aims to identify predictors of delay to diagnosis in a large sample of people with YOD and to investigate the impact of a specialist YOD service on this time to diagnosis.

A retrospective cross-sectional study.

The inpatient unit of a tertiary neuropsychiatry service in metropolitan Victoria, Australia.

People diagnosed with a YOD.

We investigated the following predictors using general linear modeling: demographics including sex and location, age at onset, dementia type, cognition, psychiatric diagnosis, and number of services consulted with prior to diagnosis.

A total of 242 inpatients were included. The mean time to diagnosis was 3.4 years. Significant predictors of delay included younger age at onset, dementia type other than Alzheimer’s disease (AD) and behavioral-variant frontotemporal dementia (bvFTD), and increased number of services consulted. These predictors individually led to an increased diagnostic delay of approximately 19 days, 5 months, and 6 months, respectively. A specialized YOD service reduced time to diagnosis by 12 months.

We found that younger age at onset, having a dementia which was not the most commonly occurring AD or bvFTD, and increasing number of services were significant predictors of diagnostic delay. A novel result was that a specialist YOD service may decrease diagnostic delay, highlighting the importance of such as service in reducing time to diagnosis as well as providing post-diagnostic support.