Quantitative characteristics of EEG in Alzheimer’s disease during cognitive tasks

Cover Page

Cite item

Full Text


In Alzheimer’s disease (AD) the EEG changes are rather diffuse and most expressed in moderate and severe cognitive disorders. Pathological changes of spectral power and EEG coherence are assumed to be related with the degree of cognitive deficit. The aim of this study: comparative analysis of spectral power and EEG coherence and their reactivity during functional tasks in AD patients with mild and moderate dementia and in agematched healthy control subjects. Twenty two AD patients with mild-to-moderate dementia and 25 controls were examined. All patients underwent EEG recordings with analysis of spectral power of the main rhythms, as well as with analysis of intra- and inter-hemispheric coherence and their dynamics during functional tasks. We found an increase in slow-wave activity (delta and theta rhythms) and a decrease in alpha activity in frontal, parietal and temporal regions of the brain. Intra- and interhemispheric coherence was significantly lower in frontal, parietal and temporal regions in AD patients compared to controls. EEG pattern was more obvious after functional tests. One may conclude that changes of spectral power and EEG coherence seem to be a sensitive indicator of cognitive decline at very early stages of neurodegenerative process.


About the authors

A. V. Sergeev

First Moscow State Medical University named after I.M. Sechenov

Email: sergeev.amd@gmail.com
Russian Federation, Moscow

A. V. Medvedeva

First Moscow State Medical University named after I.M. Sechenov

Email: sergeev.amd@gmail.com
Russian Federation, Moscow

T. G. Voznesenskaya

First Moscow State Medical University named after I.M. Sechenov

Author for correspondence.
Email: sergeev.amd@gmail.com
Russian Federation, Moscow


  1. Гнездицкий В.В. Обратная задача ЭЭГ и клиническая электро- энцефалография. Таганрог: Изд. ТРТУ, 2004.
  2. Елкин М.Н. Количественные характеристики ЭЭГ при пар- кинсонизме: связь с клиническими, когнитивными, возрастными особенностями. Дис. … канд. мед. наук. М., 1996.
  3. МКБ-10. Международная статистическая классификация болезней и проблем, связанных со здоровьем. Х пересмотр. Женева, 1995.
  4. American Psychiatric Association. Diagnostic and statistical manual of mental disorders, DSM IV, 4th ed. Washington, DC: APA, 1994.
  5. Di Carlo A., Baldereschi M., Amaducci L. et al. Incidence of dementia, Alzheimer’s disease, and vascular dementia in Italy. The ILSA Study. J. Am. Geriatr. Soc. 2002; 50: 41–48.
  6. Dierks T., Jelic V., Pascual-Marqui R.D. et al. Spatial pattern of cerebral glucose metabolism (PET) correlates with localization of intracerebral EEG generators in Alzheimer’s disease. Clin. Neurophysiol. 2000; 11: 1817–1824.
  7. Dierks T., Perisic I., Frolich L. et al. Topography of the quantitative electroencephalogram in dementia of the Alzheimer type: relation to severity of dementia. Psychiatry Res. 2001; 40: 181–194.
  8. Huang C., Wahlund L.O., Dierks T. et al. Discrimination of Alzheimer’sdisease and mild cognitive impairment by equivalent EEG sources: a cross-sectional and longitudinal study. Clin. Neurophysiol. 2000; 111: 1961–1967.
  9. Mantini M.G, Perrucci C., Del Gratta D. et al. Electrophysiological signatures of resting state networks in the human brain. PNAS 2007; 16: 104–110.
  10. Maurer K. Topography of the quantitative electroencephalogram in dementia of the Alzheimer type. Psychiatry Res. 2005; 40: 181–194. Том 5. № 2 2011 28
  11. Medvedeva A., Keeser D., Meindl T. et al. Functional connectivity in patients with early Alzheimer’s disease, MCI and healthy controls as assessed by fMRI and EEG. Res. f. Neues aus der psychiatrischen Forschung. Munchen, 2008.
  12. Prichep L.S., John E.R., Ferris S.H. et al. Quantitative EEG correlates of cognitive deterioration in the elderly. Neurobiol. Aging 2004; 15: 85–90.
  13. Saletu B., Anderer P., Paulus E. et al. EEG brain mapping in diagnostic and therapeutic assessment of dementia. Alzheimer Dis. Assoc. Disord. 1991; 5 (suppl.1): 57–75.
  14. Saletu B., Anderer P., Semlitsch H.V. Relations between symptomatology and brain function indementias: Double-blind, placebo-controlled, clinical and EEG/ERP mapping studies with nicergoline. Dement Geriatr. Cogn. Disord. 1997; 8 (Suppl. 1): 12–21.
  15. Saletu B., Anderer P., Saletu-Zyhlarz G.M., Pascual-Marqui R.D. EEG topography and tomography in diagnosis and treatment of mental disorders: evidence for a key-lock principle. Methods Find. Exp. Clin. Pharmacol. 2002; 7: 73.
  16. Shigeta M., Julin P., Almkvist O. et al. Quantitative electroencephalography power and coherence in Alzheimer’s disease and mild cognitive impairment. Dementia 2006; 7: 314–323.
  17. Schreiter-Gasser U., Gasser T., Ziegler P. Quantitative EEG analysis in early onset Alzheimer’s disease: correlations with severity, clinical characteristics, visual EEG and CCT. PNAS. 2004; 13: 46–54. 18. Vincent G., Formisano E., Prvulovic D. et al. Linden: Functional connectivity as revealed by spatial independent component analysis of fMRI measurements during rest. Hum. Brain Mapping 2004; 22: 165–178.

Supplementary files

Supplementary Files

Copyright (c) 2011 Sergeev A.V., Medvedeva A.V., Voznesenskaya T.G.

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.

СМИ зарегистрировано Федеральной службой по надзору в сфере связи, информационных технологий и массовых коммуникаций (Роскомнадзор).
Регистрационный номер и дата принятия решения о регистрации СМИ: серия ПИ № ФС 77-83204 от 12.05.2022.

This website uses cookies

You consent to our cookies if you continue to use our website.

About Cookies