Frontal Behavioural Inventory in the differential diagnosis of dementia

Objective- To evaluate diagnostic properties of the Frontal Behavioural Inventory (FBI) in patients suffering from different forms of dementia. Methods- The FBI was administered with other psychometric tests investigating cognitive performances and behavioral scales to the caregivers of 35 patients with the frontal variant of frontotemporal dementia (fv-FTD), 22 patients with Alzheimer's disease (AD) and 15 with vascular dementia (VaD). All patients were comparable for degree of dementia severity and level of executive impairment. Results- The FBI showed high concurrent validity, internal consistency and good inter-rater and test-retest reliability. The discriminant validity was also very high. A new FBI cut-off score of 23 gave 97% sensitivity and 95% specificity in distinguishing fv-FTD from non-FTD patients. Conversely, the Neuropsychiatic Inventory (NPI) score was unable to differentiate fv-FTD from AD. Conclusions- The FBI is a neurobehavioral tool suitable to distinguish fv-FTD from other forms of dementia also when data from cognitive testing or other behavioral scales fail to support the differential diagnosis.