Mortality in FTD: An Australian perspective

Abstract

AbstractTHEME: Clinical manifestationsTOPIC: Neuropsychiatry & beh neurologySUBTOPIC: NeuropsychiatryBackgroundSurvival duration in frontotemporal dementia (FTD) remains inconsistent, depending on the clinical phenotype with different risk factors identified. Risk factors to mortality include the FTD‐MND presentation, a genetic predisposition (Agarwal S et al. 2019), deficits in neuropsychological tests, imaging changes (Agarwal et al. 2019; Hodges et al. 2003) and non‐tau pathology (Roberson et al. 2005; Hodges et al. 2003). We aimed to identify survival duration and cause of death in this group.MethodAll inpatients admitted to Neuropsychiatry, based at the Royal Melbourne Hospital, in metropolitan Australia from 1992 – 2014, who were diagnosed with probably FTD of any subtype were included. Linkage data was obtained by the Australian Institute of Health and Welfare (AIHW). We reviewed their clinical information including demographics, age of symptom onset, type of presenting symptom, neuroimaging and diagnosis.ResultOf the 528 individual inpatients identified with a dementia, there were n=100 who had a diagnosis of probable FTD. There were n=76 who had a behavioural‐variant FTD (bv‐FTD), n=14 who had a language‐variant FTD (lang‐FTD) and n=10 who had FTD‐MND. 67% of the group had died. Overall median duration of survival was 10.5 years (95% CI 7.9, 12.2). There were no differences in age of death nor age onset between the three FTD‐subtypes (p=0.479, p=0.289, respectively). As expected, there were significant differences in the median survival duration of the three FTD subtypes, with FTD‐MND having the shortest duration (p=0.004). Causes of death based on ICD‐10 were predominantly dementia‐related (26.3% Other degenerative diseases of nervous system; 17.5% unspecified dementia) but also included acute myocardial infarction (7%) and alcohol‐related (7%). Standardised mortality ratios (SMRs) revealed that compared to population norms, people with FTD had 8x mortality rate.ConclusionNot unsurprisingly, FTD‐MND had the shortest duration compared to the other subtypes of FTD. The duration of survival was comparable to other studies. Causes of death revealed that a dementia was identified in almost half of cases. High SMRs suggest that FTD is a particularly “fatal” type of dementia in younger people. Investigation into risk factors to death is required.