Frontal lobe dementia. Clinical-pathologic case reports

Frontal lobe dementia (FLD) is characterised clinically by personality changes and a progressive speech disorder finally leading to mutism. In the course of the disease also other neurological syndromes may occur such as parkinsonism, a partial Klüver-Bucy-syndrome or a degeneration of motoneurons (FLD + MND). The latter leads to death within about three years. The clinical diagnosis of FLD is supported by functional (SPECT) and morphological (CT, MRI) investigations. From 1988 to 1997, 9 cases of FLD (6 female, 3 male) were clinically diagnosed at our department of Gerontology, LNK Linz. In two of these cases the clinical diagnosis was confirmed histopathologically. Characteristically, all except one patients showed a presenile beginning of the disease. The clinical course was slowly progressive with a mean duration of about 10 years. Special attention was given to additional signs and symptoms of motor neuron disease, parkinsonism and hyperorality. Six patients suffered from FLD + MND; parkinsonism (rigid-akinetic type) and a partial Klüver-Bucy-syndrome were diagnosed in 5 cases each. In histopathological investigations the incidence of FLD seems to increase. This type of dementia should be considered as an important diagnosis differential of presenile dementia-syndromes.