No previous population-based study has addressed the contribution of activation procedures to the yield of epileptiform abnormalities on serial EEGs. We assessed yield of activation-related epileptiform abnormalities and predictors of finding an activation-related abnormality with multiple EEGs in a population-based study of newly diagnosed epilepsy.
We used the resources of the Rochester Epidemiology Project to identify 449 residents of Rochester, Minnesota with a diagnosis of newly diagnosed epilepsy at age 1 year or older, between 1960 and 1994, who had at least one EEG. Information on all activation procedures (i.e., sleep, hyperventilation, and photic activation) and seizure/epilepsy characteristics was obtained by comprehensive review of medical records.
At the first EEG, the yield of epileptiform abnormalities was greatest for individuals 1 to 19 years of age at diagnosis, for each activation procedure. The yield in patients aged 1 to 19 versus ≥20 years was 21.6% versus 10.3% for sleep, 6.5% versus 3.3% for photic stimulation, and 10.3% versus 5% for hyperventilation. Among young people (aged 1–19 years), sleep was associated with an increased likelihood of finding an activation-related abnormality on any EEG. The likelihood of finding an activation-related abnormality on any EEG was decreased for postnatal symptomatic and for unknown etiology.
Among activation procedures, sleep showed the highest yield of epileptiform abnormalities. There was a low yield for photic stimulation and hyperventilation. Within each activation procedure, younger age at diagnosis had the greatest yield. Sleep is the most effective activation procedure, especially in younger patients, and should be performed when possible.
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*Department of Epidemiology, Gertrude H. Sergievsky Center, Columbia University, New York, New York, U.S.A.;
†Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, New York, U.S.A.;
‡Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, New York, U.S.A.;
§Department of Neurology, Mayo Clinic, Rochester, Minnesota, U.S.A. Jeffrey R. Buchhalter is now with the Department of Pediatrics, University of Calgary, Calgary, Alberta, Canada; and
‖Division of Epidemiology, New York State Psychiatric Institute, New York, New York, U.S.A.
Address correspondence and reprint requests to Dale C. Hesdorffer, PhD, Gertrude H. Sergievsky Center, Columbia University, 630 West 168th St, P & S Box 16, New York, NY 10032, U.S.A.; e-mail: firstname.lastname@example.org.
Dr. Hauser was a consultant Federal Aviation Administration; received funding for travel from the American Epilepsy Society and received research support from the CDC and from the NIH through #R01 NS043472 [Co-I]. He is on the editorial advisory board of Epilepsy Research, Acta Scandinavia Neurologica and Neuroepidemiology. He is a member of a data and safety monitoring board for Neuropace.
Buchhalter served as a consultant for Lundbeck, Inc, Eisai, Ltd, and Upsher-Smith; is on the editorial advisory board for Clinical Neurology News; received research support from the Alberta Children's Hospital Foundation and from the NIH through #R01 NS043472 [Co-I]. He also provides clinical evaluations and neurophysiology services that will not be benefitted by this paper.
Dr. Hesdorffer serves as consultant at the Mount Sinai Medical Center, Injury Prevention Center, and at NYU Epilepsy Center; she received research support from CDC, NINDS, Epilepsy Foundation of America, PCORI, CURE, and the Epilepsy Study Consortium; she serves on advisory boards for Upsher-Smith Laboratories, Acorda and Cyberonics, and has received funding for travel from the University of Bologna, Upsher-Smith Laboratories, Acorda, Cyberonics, and International League Against Epilepsy. She serves as Associate Editor for Epilepsia, is on the Editorial Board of Epilepsy and Behavior, and is a contributing editor for Epilepsy Currents.
Ottman serves on the scientific advisory board for and holds stock options in Trigeminal Solutions, Inc; received funding for travel from the École des Hautes Etudes en Santé Publique, the University of Bologna, the University of Calgary, Ettore Majorana Centre for Scientific Culture, the American Epilepsy Society, and the International League Against Epilepsy; and received research support from the NIH. The remaining author has no funding or conflicts of interest to disclose.
This research was supported by U.S. NIH grant R01 NS043472 from the NINDS. Study data were obtained from the Rochester Epidemiology Project, which is supported by the NIA of the NIH under R01 AG034676. The content of this manuscript is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.
Presented as a poster at the XIV Congresso Nazionale di Neuroepidemiologia, Milan, Italy, November 21–22, 2014.
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