The FAB: a Frontal Assessment Battery at bedside.

OBJECTIVE: To devise a short bedside cognitive and behavioral battery to assess frontal lobe functions.

METHODS: The designed battery consists of six subtests exploring the following: conceptualization, mental flexibility, motor programming, sensitivity to interference, inhibitory control, and environmental autonomy. It takes approximately 10 minutes to administer. The authors studied 42 normal subjects and 121 patients with various degrees of frontal lobe dysfunction (PD, n = 24; multiple system atrophy, n = 6; corticobasal degeneration, n = 21; progressive supranuclear palsy, n = 47; frontotemporal dementia, n = 23).

RESULTS: The Frontal Assessment Battery scores correlated with the Mattis Dementia Rating Scale scores (rho = 0.82, p < 0.01) and with the number of criteria (rho = 0.77, p < 0.01) and perseverative errors (rho = 0.68, p < 0.01) of the Wisconsin Card Sorting Test. These variables accounted for 79% of the variance in a stepwise multiple regression, whereas age or Mini-Mental State Examination scores had no significant influence. There was good interrater reliability (kappa = 0.87, p < 0.001), internal consistency (Cronbach's coefficient alpha = 0.78), and discriminant validity (89.1% of cases correctly identified in a discriminant analysis of patients and controls).

CONCLUSION: The Frontal Assessment Battery is easy to administer at bedside and is sensitive to frontal lobe dysfunction.