Subscores of the FAB differentiate frontotemporal lobar degeneration from AD.

OBJECTIVE

To determine the clinical utility of the Frontal Assessment Battery (FAB), a short test of frontal lobe functions, in differentiating frontotemporal lobar degeneration (FTLD) from Alzheimer disease (AD).

METHODS

FAB total scores and subscores for 23 subjects with FTLD and 31 subjects with AD were compared for sensitivity, specificity, and positive predictive value. Concurrent validity of the FAB with the Mini-Mental State Examination (MMSE) and other scales was also assessed.

RESULTS

The FAB did not have positive predictive value for FTLD. Total FAB scores did not differ between the FTLD and AD groups. However, three subtests of the FAB (mental flexibility, motor programming, and environmental autonomy) demonstrated significant differences between the two groups. Total FAB scores correlated with scores on the MMSE, a more general test of cognition.

CONCLUSION

The Frontal Assessment Battery did not discriminate subjects with frontotemporal lobar degeneration from those with Alzheimer disease, though certain subtests may be helpful in differential diagnosis.