The first known neurophysiologic recordings of animals were performed by Richard Caton in 1875. The advent of recording the electrical activity of human beings took another half century to occur. Hans Berger, a German psychiatrist, pioneered the EEG in humans in 1924. The EEG is an electrophysiological technique for the recording of electrical activity arising from the human brain. Given its exquisite temporal sensitivity, the main utility of EEG is in the evaluation of dynamic cerebral functioning. EEG is particularly useful for evaluating patients with suspected seizures, epilepsy, and unusual spells. With certain exceptions, practically all patients with epilepsy will demonstrate characteristic EEG alterations during an epileptic seizure (ictal, or during-seizure, recordings). Most epilepsy patients also show characteristic interictal (or between-seizure) epileptiform discharges (IEDs) termed spike (<70 μsec duration), spike and wave, or sharp-wave (70–200 μsec duration) discharges.
EEG has also been adopted for several other clinical indications. For example, EEG may be used to monitor the depth of anesthesia during surgical procedures; given its great sensitivity in showing sudden changes in neural functioning even as they first occur, it has proven quite helpful in this setting in monitoring for potential complications such as ischemia or infarction. EEG waveforms may also be averaged, giving rise to evoked potentials (EPs) and event-related potentials (ERPs), potentials that represent neural activity of interest that is temporally related to a specific stimulus. EPs and ERPs are used in clinical practice and research for analysis of visual, auditory, somatosensory, and higher cognitive functioning.
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ISBN: 978-0-9979756-0-4
Copyright ©2016 by American Epilepsy Society
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Care has been taken to confirm the accuracy of the information presented and to describe generally accepted practices. However, the authors, editors, and publisher are not responsible for errors or omissions or for any consequences from application of the information in this book and make no warranty, express or implied, with respect to the contents of the publication.
This text is designed to assist clinicians by providing a framework for evaluating and treating patients. It is not intended to establish a community standard of care, replace a clinician's medical judgment, or establish a protocol for all patients. The clinical conditions contemplated by the text will not fit or work with all patients. Approaches not covered here may be appropriate.
The authors, editors, and publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accordance with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any change in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new or infrequently employed drug.
Some drugs and medical devices presented in this publication have Food and Drug Administration (FDA) clearance for limited use in restricted research settings. It is the responsibility of the health care provider to ascertain the FDA status of each drug or device planned for use in their clinical practice.
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Attribution
This publication is provided by the American Epilepsy Society (AES) for use by educators and students. Additional resources from AES are available to the medical and scientific community. Visit www.aesnet.org to find more.
The following is an example of proper attribution for this work: St. Louis, EK, Frey, LC (Eds.). Electroencephalography (EEG): An introductory text and atlas of normal and abnormal findings in adults, children and infants. Chicago, IL: American Epilepsy Society; 2016. http://dx.doi.org/10.5698/978-0-9979756-0-4.
About the American Epilepsy Society
The American Epilepsy Society is a medical and scientific society whose members are engaged in research and clinical care for people with epilepsy. For more than 75 years, AES has provided a dynamic global forum where professionals from academia, private practice, not-for-profit, government, and industry can learn, share, and grow. Find out more at www.aesnet.org.
The Society seeks to promote interdisciplinary communications, scientific investigation, and exchange of clinical information about epilepsy.
This publication was produced through the volunteer efforts of the AES Council on Education, Student & Resident Education & Curriculum Committee, and the EEG Work Group.
Correspondence
American Epilepsy Society, 135 S. LaSalle St., Suite 2850, Chicago, IL 60603, Phone: (312) 883-3800 | email: gro.tensea@ofni | website: www.aesnet.org
Erik K. St. Louis, MD - Ex Officio Work Group Chair, Primary Author & Editor, Departments of Neurology and Medicine, Mayo Clinic 200 First Street SW, Rochester, MN 55905, Phone: (507) 266-7456 | email: ude.oyam@kirE.siuoLtS
Lauren Frey, MD - Workgroup Chair & Editor, Department of Neurology, University of Colorado, Phone: (720) 848-8583 | email: ude.revnedcu@yerF.neruaL
