Naslov
Effects of neurodegeneration on the topology and dynamics of the M50 cortical network: An MEG study

Autori
Josef Golubic, Sanja ; Aine, Cheryl J. ; Stephen, Julia M. ; Adair, John C. ; Knoefel, Janice E. ; Supek, Selma

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
WCMPBE 2012, Book of Abstract / Liu, Depei ; Fan, Yubo ; Hu, Yimin - Peking, 2012

Skup
World Congress on Medical Physics and Biomedical Engineering, 2012.

Mjesto i datum
Peking, Kina, 26.05.2012. - 31.05.2012

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Alzheimer disease (AD); dementia; neurodegeneration; M50 auditory network; auditory oddball paradigm; MEG

Sažetak
A passive auditory odd-ball paradigm, in conjunction with MEG source localization methods, were used to explore the topology and dynamics of the earliest auditory networks underlying the M50 complex of patients diagnosed with mild cognitive impairment (MCI) or probable Alzheimer’s disease (AD), and elderly controls. Effects of aging on the source dynamics of early activity (40-50 ms) in the superior temporal gyrus (STG) were reported previously (Aine et al, 2005), along with a P50 gating deficit in AD patients (Thomas et al, 2009). While multiple generators of the M50 complex have been suggested, there is no agreement on the activated network. Twenty subjects, 10 diagnosed as MCI or probable AD patients and 10 elderly controls, 63 to 83 years of age, participated in a passive auditory oddball task. Binaurally presented stimuli consisted of 400 standard (1.000 Hz, p=0.8) and 100 deviant (1.200 Hz, p=0.2) tones. Magnetic fields were recorded with a CTF 275-channel MEG system (VSM MedTech, Ltd.) at the Mind Research Network. We used a Calibrated Start Spatio-Temporal (CSST) analysis (Ranken et al., 2002) and identified bilateral STG and prefrontal (PF) sources underlying the auditory M50 complex in elderly controls. While STG sources were localized in 20/20 (in 18/20 bilateral) participants to both stimuli, localization of PF sources was strongly dependent upon the stimulus condition (in 4/20 subjects for standards and in 11/20 for deviants) and patient category (no PF in 9/10 MCI/AD ; 5/5 AD, 4/5 MCI). Within the M50 complex the earliest activity of the STG sources was: 1) modulated by the activation of the PF source and 2) affected by degenerative processes associated with MCI and AD. These findings highlight the strength of MEG source localization techniques to explore early complex interactions within cortical auditory networks as potential biomarkers of cortical dysfunction related to neurodegeneration processes.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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