Dementia of frontal type and the focal lobar atrophies

Abstract

Dementia of frontal type(DFT) and the other focal lobar atrophies challenge the clinician to assess patients with dementia thoroughly. DFT presents with characteristic behavioural and personality changes, and operational criteria have recently been devised to assist in the assessment and diagnosis. A significant proportion of cases present with functional psychiatric disorders including mood disturbance. Diogenes syndrome may be a variant of DFT. A number of syndromes associated with focal lobar atrophy of other brain regions have also been described, most common of these is primary progressive aphasia (PPA). Bedside cognitive and formal neuropsychological testing, and neuroimaging—both functional (SPECT) and anatomical—may assist in the diagnosis of these disorders. At post-mortem, non-specific atrophy is present; in DFT, the frontal lobes are affected, and in PPA, the focus of pathology is the dominant temporal lobe. Only a minority of cases show Pick cells and Picks bodies, in the remainder non-specific neuronal loss and gliosis are present