GARCIA adolfo Martin
congresos y reuniones científicas
Beyond variability: Unveiling brain connectivity alterations in frontotemporal dementia
SEDEÑO, L., GARCÍA, A. M., FITIPALDI, S., ABREVAYA, S., GARCÍA-CORDERO, I., BAEZ, S., DE LA FUENTE, L., TORRALVA, T. & IBÁÑEZ, A.
Congreso; 18th World Congress of the International Organization of Psychophysiology; 2016
International Organization of Psychophysiology
Introduction: Behavioral-variant frontotemporal dementia (bvFTD) is characterized by marked functional connectivity alterations, which may represent a key biomarker contributing to the early diagnosis of this condition.However, to guarantee the clinical robustness of such abnormalities, it is critical to assess them across heterogeneous contexts (due to differences in MRI equipment and acquisition parameters, clinical diagnostic teams and participants? financial and socio-cultural profiles). To this end, we exploredwhether graph measures (asensitive approach to study functional connectivity as a complex network of interconnected elements)could consistently distinguish bvFTDpatients from controls.Crucially, to evaluate the specificity of altered connectivity patterns in the former group, we replicated our study considering three other neurological conditions. Methods: We enrolled 52 bvFTDpatients and 60 controls from three international clinical centers with extensive experience in neurodegeneration (the frontotemporal dementia research group, Australia; INECO, Argentina; and San Ignacio University Hospital, Colombia). Three additional patient groups were included, namely,fronto-insular stroke (FIS), Alzheimer?s disease (AD), and primary progressive aphasia (PPA). All participantsunderwent resting-state fMRI recordingswith different MRI scanners and acquisition parameters. Using graph theory, we measured the integration of long-range connections, local connectivity levels, and centrality features of brain regions, thus estimating the relevance of an area within the brain network.Results:Compared to controls, bvFTD patients presented consistent alterations in all graph measures across centers. Also, these measures discriminated bvFTD patients from the other disease groups. These patients differed from the FIS group in the integration of connections and in local connectivity. Differences between bvFTD and both AD and PPA concerned anatomically distinct alterations of network centrality. Discussion:To our knowledge, this is the first multicenter report exploring functional connectivity viagraph theory on bvFTD. Our approach was robust enough to discriminate bvFTD patients from both healthy controls and other neurological samples (FIS, PPA, and AD) across centers. The consistency and replicability of these findings in a highly heterogeneous context highlight graph-theory measures as a potential gold-standard approach for brain network analysis. This represents a critical step towards the eventual clinical application of this method as a biomarker signature for neurodegenerative diseases. [Work partially supported by CONICET, CONICYT/FONDECYT Regular (1130920), COLCIENCIAS (1115-545-31374 and 1115-569-33858), FONCyT-PICT 2012-0412, FONCyT-PICT 2012-1309, FONDAP 15150012, and INECO Foundation.].