Primary progressive aphasia (PPA) is a neurodegenerative disease of insidious onset presenting with progressive isolated loss of language function, without significant impairment in other cognitive domains. Current diagnostic criteria require the language dysfunction to remain isolated for at least two years.
Reported literature suggests that 70% of patients have tau-negative ubiquitin positive pathology with a TAR DNA binding protein (TDP-43), 20% tau-positive Pick'disease, and 10% have AD pathology. In a recent study of 100 patients with SD, 24 had autopsy - 18 had FTD-U (13/13 TDP-43 positive), 3 had classical tau pathology, and 3 had AD. There were no intranuclear lentiform TDP-43 inclusions in any of the patients.
Performing more detailed studies to characterize patients with the logopenic variant of PPA, scientists at the Penn FTD Center have developed techniques to study the CSF, perform detailed analyses of MRI scans, and to relate language, MRI and CSF characteristics together to provide an accurate diagnosis of patients with PPA so that the most effective treatments can be applied.
Major research on disease:
An overview on Primary Progressive Aphasia and its variants. Selective impairment of verb processing associated with pathological changes in Brodmann areas 44 and 45 in the motor neuron disease-dementia-aphasia syndrome. Rapidly progressive aphasic dementia with motor neuron disease: a distinctive clinical entity.