Predictors of survival and progression in behavioural variant frontotemporal dementia

Predicting the course of behavioural variant frontotemporal dementia (bvFTD) remains a major clinical challenge. This study aimed to identify factors that predict survival and clinical progression in bvFTD.

Consecutive patients with clinically probable bvFTD were prospectively followed up over an 8-year period. Baseline neuropsychological variables, presence of a known pathogenic frontotemporal dementia gene mutation and a systematic visual magnetic resonance imaging assessment at baseline were examined as candidate predictors using multivariate modelling.

After screening 121 cases, the study cohort consisted of 75 patients with probable bvFTD, with a mean age of 60.8 ± 8.5 years, followed up for a mean duration of 7.2 ± 3.5 years from symptom onset. Median survival time from disease onset was 10.8 years and median survival, prior to transition to nursing home, was 8.9 years. A total of 25 of the 75 patients died during the study follow-up period. Survival without dependence was predicted by shorter disease duration at presentation (hazard ratio, 0.49, P = 0.001), greater atrophy in the anterior cingulate cortex (hazard ratio, 1.75, P = 0.047), older age (hazard ratio, 1.07, P = 0.026) and a higher burden of behavioural symptoms (hazard ratio, 1.04, P = 0.015). In terms of disease progression, presence of a known pathogenic frontotemporal dementia mutation (β = 0.46, P < 0.001) was the strongest predictor of progression. Deficits in letter fluency (β = -0.43, P = 0.017) and greater atrophy in the motor cortex (β = 0.51, P = 0.03) were also associated with faster progression.

This study provides novel clinical predictors of survival and progression in bvFTD. Our findings are likely to have an impact on prognostication and care planning in this difficult disease.