New behavioural variant FTD criteria and clinical practice

Since the first descriptions of circumscribed frontotemporal atrophies, and the first statement published by the Lund and Manchester groups, consensus clinical and pathological criteria for frontotemporal dementia (FTD) have been increasingly refined. The last international behavioural variant FTD criteria (FTDC) (Rascovsky et al., 2011) are the most sensitive, operational and reliable, for the clinical syndrome. Previously exclusion features, like early and severe amnestic syndrome or spatial disorientation, which turn out to be not so rare, are taken into account, as well as imaging, and biomarkers suggestive of other pathologies like Alzheimer's disease. So far, clinical features do not seem very helpful in predicting the underlying histopathology, although there are some clues, mainly related to neurological features (e.g. motor neuron disease, extra-pyramidal symptoms or language disorders), or associated disorders (e.g. Paget disease of bone) or genetics. BvFTD remains a difficult diagnosis at very early stage, which accounts for the delay of diagnosis, especially in late onset, where the frontotemporal atrophy may not be striking. At very young onset, psychiatric diseases must be ruled out. More systematic assessment of social cognition could be helpful. Further biomarkers are expected. Systematic use of recent criteria, for BvFTD and other neurodegenerative diseases especially AD, will contribute to make early and correct diagnoses in excluding or suggesting alternative diagnoses. Post-mortem assessment, with detailed recording of clinical information, is essential to progress.