engleski

Neuromagnetic and neuropsychological measures in discriminating between aging, MCI, and AD subject categories

Magnetoencephalography (MEG) measurements with excellent millisecond time resolution offer a valuable noninvasive approach for assessing the pathological changes in neuronal activation pattern. In this study we used spatio-temporal source localization methods to identify the activated cortical networks evoked by simple auditory tone stimuli within an add-ball paradigm and a battery of neuropsychological tests in an effort to discriminate between patients diagnosed as potential MCI and AD compared to the age-matched controls. MEG brain cortical activation patterns were examined in 10 elderly controls (>64 years) and 10 elderly diagnosed as MCI or AD patients. MEG data were recorded with the CTF 275 channel whole-head system in a magnetically shielded room at the MIND Research Network in Albuquerque, New Mexico. Multiple dipole source localization and temporal dynamics estimation were conducted during 30-200 ms time interval using MRVIEW Calibrated Start Spatio Temporal (CSST) algorithm [1]. Prior to acquiring auditory data all subjects underwent extensive neuropsychological/memory screening.. We found a strong correlation of the MMSE/REY memory test scores and early activation of frontal lobe network for both frequently and rarely presented stimuli. Frontal current dipoles were, however, identified only in high-functional controls (MSE=30 and REY≥23) for frequent tones. For rarely presented deviants the evoked frontal activity was identified only in healthy controls and MCI patients and was consistently missing in AD patients. Lack of a frontal activity and prominent differences noted in the dynamic patterns of early STG activation [2] combined with strong correlation between neuropsychological/memory and neuromagnetic functional measures is likely to be of a clinical value in discriminating between the subject categories. It remains to be confirmed if this type of a very easy to deliver, simple, auditory tone task can be useful for a large scale regular screening procedure that can yield also a preclinical marker for AD. REFERENCE : [1] Ranken DM et al: MEG/EEG forward and inverse modeling using MRIVIEW ; Proceeding of Biomag 2002 785-787. [2] Supek, Selma ; Josef Golubic, Sanja ; Bryant, Jennifer ; Donahue, Chris ; Montañ o, Rebecca ; Adair, John ; Hart, Blaine ; Knoefel, Janice ; Stephen, Julia ; Aine, Cheryl: Neuromagnetic auditory activity reflects differences between normal aging, MCI and AD subjects: An oddball study ; Biomagnetism:Interdisciplinary Research and Exploration (Proceedings of Biomag 2008), R. Kakigi, K. Yokosawa, S. Kuriki (Eds), Hokkaido University Press, Sapporo, 2008, pp 171-173.

Magnetoencephalography (MEG); MCI patients; AD patients

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