Behavioural-variant frontotemporal dementia: an update

Behavioural-variant frontotemporal dementia (bvFTD) is characterised by insidious changes in personality and interpersonal conduct that reflect progressive disintegration of the neural circuits involved in social cognition, emotion regulation, motivation and decision making. The underlying pathology is heterogeneous and classified according to the presence of intraneuronal inclusions of tau, TDP-43 or occasionally FUS. Biomarkers to detect these histopathological changes in life are increasingly important with the development of disease-modifying drugs. Gene mutations have been found which collectively account for around 10-20% of cases including a novel hexanucleotide repeat on chromosome 9 (C9orf72). The recently reviewed International Consensus Criteria for bvFTD propose three levels of diagnostic certainly: possible, probable and definite. Detailed history taking from family members to elicit behavioural features underpins the diagnostic process with support from neuropsychological testing designed to detect impairment in decision-making, emotion processing and social cognition. Brain imaging is important for increasing the level of diagnosis certainty. Carer education and support remain of paramount importance.