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Early disturbances of gamma band dynamics in mild cognitive impairment

Missonnier, Pascal ; Herrmann, François ; Michon, Agnès ; Fazio-Costa, Lara ; Gold, Gabriel ; Giannakopoulos, Panteleimon

In: Journal of Neural Transmission, 2010, vol. 117, no. 4, p. 489-498

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    Titre
    • Early disturbances of gamma band dynamics in mild cognitive impairment
    Auteur
    • Missonnier, Pascal. Clinical Neurophysiology and Neuroimaging Unit, Division of Neuropsychiatry, Department of Psychiatry, Geneva University Hospitals, University of Geneva, 2 chemin du Petit-Bel-Air, Chêne-Bourg, 1225, Geneva, Switzerland
    • Herrmann, François. Department of Rehabilitation and Geriatrics, Geneva University Hospitals, University of Geneva, Geneva, Switzerland
    • Michon, Agnès. Division of Geriatric Psychiatry, Department of Psychiatry, Geneva University Hospitals, University of Geneva, Geneva, Switzerland
    • Fazio-Costa, Lara. Department of Rehabilitation and Geriatrics, Geneva University Hospitals, University of Geneva, Geneva, Switzerland
    • Gold, Gabriel. Department of Rehabilitation and Geriatrics, Geneva University Hospitals, University of Geneva, Geneva, Switzerland
    • Giannakopoulos, Panteleimon. Division of Geriatric Psychiatry, Department of Psychiatry, Geneva University Hospitals, University of Geneva, Geneva, Switzerland
    Type de document
    • Postprint
    Langue
    • Anglais
    Publié dans
    • Journal of Neural Transmission, 2010, vol. 117, no. 4, p. 489-498. Springer Vienna
    Autre version électronique
    Identifiant OAI-PMH
    • oai:doc.rero.ch:310916
    Summary
    Recent studies have indicated that gamma band oscillations participate in the temporal binding needed for the synchronization of cortical networks involved in short-term memory and attentional processes. To date, no study has explored the temporal dynamics of gamma band in the early stages of dementia. At baseline, gamma band analysis was performed in 29 cases with mild cognitive impairment (MCI) during the n-back task. Based on phase diagrams, multiple linear regression models were built to explore the relationship between the cognitive status and gamma oscillation changes over time. Individual measures of phase diagram complexity were made using fractal dimension values. After 1year, all cases were assessed neuropsychologically using the same battery. A total of 16 MCI patients showed progressive cognitive decline (PMCI) and 13 remained stable (SMCI). When adjusted for gamma values at lag −2, and −3ms, PMCI cases displayed significantly lower average changes in gamma values than SMCI cases both in detection and 2-back tasks. Gamma fractal dimension of PMCI cases displayed significantly higher gamma fractal dimension values compared to SMCI cases. This variable explained 11.8% of the cognitive variability in this series. Our data indicate that the progression of cognitive decline in MCI is associated with early deficits in temporal binding that occur during the activation of selective attention processes