Frontal-executive versus posterior-perceptual mental status deficits in early-onset dementias.

BACKGROUND

Compared to late-onset dementias, early-onset dementias (EODs) may have greater focal cognitive involvement with differences in frontal-executive compared to posterior-perceptual deficits.

OBJECTIVE

This study evaluated whether mental status screening based on this frontal-posterior axis can distinguish EODs.

METHODS

Twenty-three patients each with early-onset Alzheimer's disease (eAD), frontotemporal dementia (FTD), or subcortical ischemic vascular disease (SIVD), and 20 normal controls underwent the Frontal Assessment Battery (FAB) and the Perceptual Assessment Battery (PAB).

RESULTS

Compared to controls, SIVD and FTD groups were impaired on the FAB whereas eAD and SIVD groups were impaired on the PAB. The FAB/PAB ratio further differentiated the groups (F(3,85) = 26.49, P < .001). For sensitivities and specificities of 93%, a cut-off score of 1.25 on the FAB/PAB distinguished eAD, and a cut-off of 0.83 distinguishing FTD.

CONCLUSION

Although preliminary, this study indicates that mental status screening based on frontal versus posterior cortical functions may help clinicians diagnose EODs.