Primary progressive aphasia (PPA) is a clinical label for a heterogeneous group of diseases and syndromes in which a neurodegenerative disorder presents with aphasic symptoms in the initial stages. To date, PPA research has focused on brain imaging, neuropsychology, and biochemical markers of the disease and virtually nothing is known about the neurophysiology of PPA. Simple language-based tasks will be administered to gain insight into the neurophysiology of language processing in PPA patients with the target of identifying different spatio-temporal signatures of language processing in the various degenerative diseases that cause PPA. The absence or degradation of signal components leads to specific disabilities (=symptoms) in language processing.
The project will use the non-invasive techniques of event-related magnetoencephalography (MEG) and electroencephalography (EEG). This neurophysiology project will be embedded as a sub-project in a large prospective study of PPA (n=200) with a multi-disciplinary team investigating neuropsychology and imaging (MRI and PET) of PPA. The specific aim of this project is to create an electrophysiological landscape of the various forms of PPA. The deeper understanding of language processing can inform mechanistic understanding of PPA subtypes and offers potential to identify biomarkers that could differentiate between the different pathologies that can cause PPA both for diagnosis and monitoring symptomatic interventions.
Furthermore, detailed information about the spatio-temporal pattern of language processing in PPA is fundamental for the future development of treatment options like speech therapy and might lead to treatment approaches with transcranial magnetic stimulation (TMS).