Prognostic relevance of quantitative topographical EEG in patients with poststroke aphasia

Copyright 2002 Elsevier Science (USA). All rights reserved.In this prospective study we analyzed the prognostic value of topographical quantitative EEG (qEEG) in poststroke aphasia. Twenty-three right-handed patients (ages 56 12 years) with different types of aphasia were studied. Quantitative EEG under resting conditions and an aphasia test battery were applied twice, 2 and 8 weeks after a stroke. EEG power fast Fourier transform was performed for delta (2-3.5 Hz), theta (4-7.5 Hz), alpha (8-13 Hz), and beta (13.5-20 Hz) frequency bands. EEG abnormalities within and outside speech relevant areas are related to restitution of poststroke aphasia. In the ischemic regions they indicate local disturbances; outside they reflect failures in neuronal networks involved in the generation and propagation of the alpha rhythm