Der zerebrale Glukosestoffwechsel bei semantischer Demenz im Vergleich zur primär progressiven Aphasie

Zusammenfassung

Die semantische Demenz (SemD) gehört neben der primär progressiven Aphasie (PA) und der frontotemporalen Demenz zur Gruppe der Demenzerkrankungen mit frontotemporaler, lobärer Degeneration (FTLD). Mittels Positronenemissionstomographie (PET) wurden 8 Patienten mit SemD und 7 Patienten mit PA untersucht. Patienten mit SemD zeigten eine signifikante Minderung des Glukosestoffwechsels im rechten Temporallappen (Gyrus fusiformis, Gyrus temporalis inferior) im Vergleich zu den Patienten mit PA. Dieser Befund unterstreicht die Rolle der PET in der Differenzialdiagnose von Demenzen aus der Gruppe der FTLD.

Abstract

Objective Semantic dementia (SemD) and progressive non-fluent aphasia (PA) are dementia syndromes associated with frontotemporal lobar degeneration (FTLD). There is evidence for a common pattern of cerebral glucose metabolism in FTLD. However a few reports exist, pointing at a differential distribution of cerebral hypometabolism as regards SemD and PA. The aim of this study was to quest for areas of decreased metabolism in SemD as compared to PA. Methods 8 patients with SemD and 7 patients with PA were examined using [18F]fluorodeoxyglucose positron emission tomography. Scans were analysed with statistical parametric mapping (SPM2). Results A significant decrease in metabolism in SemD as compared to PA was detected in the right temporal lobe (fusiform gyrus, Brodmann area 37; inferior temporal gyrus, Brodmann area 19). Conclusions Despite the limited number of patients included, this observation supports previous results of a left accentuated but bilateral temporal hypometabolism in SemD. These findings emphasize differences in regional cerebral metabolism as biological correlates for the different clinical presentations of dementias associated with FTLD.

Schlüsselwörter

frontotemporale lobäre Degeneration - Positronenemissionstomographie - semantische Demenz - primär progressive Aphasie - SPM2

Key words

frontotemporal lobar degeneration - positron emission tomography - semantic dementia - progressive non-fluent aphasia - SPM2

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