Intraindividual analysis of antiepileptic drug effects on EEG background rhythms

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

Antiepileptic drug (AED) therapy with either phenytoin or carbamazepine has been associated with generalized slowing of EEG background rhythms. These effects have been seen in groups of patients undergoing D manipulation, although the background slowing has been highly variable from patient to patient. Background slowing may represent an objective physiologic measure of drug impact on cerebral function and could be useful in monitoring for AED neurotoxicity in individual patients. This would require an intraindividual analysis of AED effects on EEG background rhythms. The present study was designed to develop a methodology for intraindividual analysis of EEG background changes and to apply this methodology to patients beginning or ending chronic AED therapy. EEG recordings were obtained under controlled conditions in 31 healthy subjects and were repeated after an interval of 12-16 weeks. EEG background rhythms from each record were analyzed using the fast Fourier transform, and test-retest differences for several quantitative measures were calculated from each subject's paired recordings. EEG recordings were also obtained in 6 patients beginning or ending chronic AED therapy. Test-retest differences for each patient's quantitative EEG measures were statistically compared with the distributions of test-retest measures obtained from the healthy controls. AED therapy was associated with an increase in absolute delta and/or theta power and a slowing of the dominant posterior rhythm; however, these EEG background changes varied widely in degree from patient to patient. Intraindividual analysis revealed that 5 patients had statistically significant slowing relative to the control group on at least 1 of the 9 target quantitative EEG measures, as well as a composite measure. Statistically significant slowing was also seen as a group effect. The results suggest that among patients undergoing chronic therapy with phenytoin or carbamazepine there are widely different degrees of EEG background slowing, often significantly beyond that expected on the basis of test-retest variability. Intraindividual analysis of the EEG background may be a practical objective measure of a patients unique response to chronic AED therapy.

Original languageEnglish (US)
Pages (from-to)186-193
Number of pages8
JournalElectroencephalography and Clinical Neurophysiology
Volume90
Issue number3
DOIs
StatePublished - 1994

Fingerprint

Anticonvulsants
Electroencephalography
Drug Therapy
Carbamazepine
Phenytoin
Fourier Analysis
Healthy Volunteers
Control Groups

Keywords

  • Antiepileptic drugs
  • Carbamazepine
  • EEG frequency analysis
  • Epilepsy
  • Phenytoin

ASJC Scopus subject areas

  • Clinical Neurology
  • Neuroscience(all)

Cite this

Intraindividual analysis of antiepileptic drug effects on EEG background rhythms. / Salinsky, Martin; Oken, Barry; Morehead, L.

In: Electroencephalography and Clinical Neurophysiology, Vol. 90, No. 3, 1994, p. 186-193.

Research output: Contribution to journalArticle

@article{428640eb1f954e78aef6388cd84957b7,
title = "Intraindividual analysis of antiepileptic drug effects on EEG background rhythms",
abstract = "Antiepileptic drug (AED) therapy with either phenytoin or carbamazepine has been associated with generalized slowing of EEG background rhythms. These effects have been seen in groups of patients undergoing D manipulation, although the background slowing has been highly variable from patient to patient. Background slowing may represent an objective physiologic measure of drug impact on cerebral function and could be useful in monitoring for AED neurotoxicity in individual patients. This would require an intraindividual analysis of AED effects on EEG background rhythms. The present study was designed to develop a methodology for intraindividual analysis of EEG background changes and to apply this methodology to patients beginning or ending chronic AED therapy. EEG recordings were obtained under controlled conditions in 31 healthy subjects and were repeated after an interval of 12-16 weeks. EEG background rhythms from each record were analyzed using the fast Fourier transform, and test-retest differences for several quantitative measures were calculated from each subject's paired recordings. EEG recordings were also obtained in 6 patients beginning or ending chronic AED therapy. Test-retest differences for each patient's quantitative EEG measures were statistically compared with the distributions of test-retest measures obtained from the healthy controls. AED therapy was associated with an increase in absolute delta and/or theta power and a slowing of the dominant posterior rhythm; however, these EEG background changes varied widely in degree from patient to patient. Intraindividual analysis revealed that 5 patients had statistically significant slowing relative to the control group on at least 1 of the 9 target quantitative EEG measures, as well as a composite measure. Statistically significant slowing was also seen as a group effect. The results suggest that among patients undergoing chronic therapy with phenytoin or carbamazepine there are widely different degrees of EEG background slowing, often significantly beyond that expected on the basis of test-retest variability. Intraindividual analysis of the EEG background may be a practical objective measure of a patients unique response to chronic AED therapy.",
keywords = "Antiepileptic drugs, Carbamazepine, EEG frequency analysis, Epilepsy, Phenytoin",
author = "Martin Salinsky and Barry Oken and L. Morehead",
year = "1994",
doi = "10.1016/0013-4694(94)90090-6",
language = "English (US)",
volume = "90",
pages = "186--193",
journal = "Electroencephalography and Clinical Neurophysiology",
issn = "0013-4694",
publisher = "Elsevier BV",
number = "3",

}

TY - JOUR

T1 - Intraindividual analysis of antiepileptic drug effects on EEG background rhythms

AU - Salinsky, Martin

AU - Oken, Barry

AU - Morehead, L.

PY - 1994

Y1 - 1994

N2 - Antiepileptic drug (AED) therapy with either phenytoin or carbamazepine has been associated with generalized slowing of EEG background rhythms. These effects have been seen in groups of patients undergoing D manipulation, although the background slowing has been highly variable from patient to patient. Background slowing may represent an objective physiologic measure of drug impact on cerebral function and could be useful in monitoring for AED neurotoxicity in individual patients. This would require an intraindividual analysis of AED effects on EEG background rhythms. The present study was designed to develop a methodology for intraindividual analysis of EEG background changes and to apply this methodology to patients beginning or ending chronic AED therapy. EEG recordings were obtained under controlled conditions in 31 healthy subjects and were repeated after an interval of 12-16 weeks. EEG background rhythms from each record were analyzed using the fast Fourier transform, and test-retest differences for several quantitative measures were calculated from each subject's paired recordings. EEG recordings were also obtained in 6 patients beginning or ending chronic AED therapy. Test-retest differences for each patient's quantitative EEG measures were statistically compared with the distributions of test-retest measures obtained from the healthy controls. AED therapy was associated with an increase in absolute delta and/or theta power and a slowing of the dominant posterior rhythm; however, these EEG background changes varied widely in degree from patient to patient. Intraindividual analysis revealed that 5 patients had statistically significant slowing relative to the control group on at least 1 of the 9 target quantitative EEG measures, as well as a composite measure. Statistically significant slowing was also seen as a group effect. The results suggest that among patients undergoing chronic therapy with phenytoin or carbamazepine there are widely different degrees of EEG background slowing, often significantly beyond that expected on the basis of test-retest variability. Intraindividual analysis of the EEG background may be a practical objective measure of a patients unique response to chronic AED therapy.

AB - Antiepileptic drug (AED) therapy with either phenytoin or carbamazepine has been associated with generalized slowing of EEG background rhythms. These effects have been seen in groups of patients undergoing D manipulation, although the background slowing has been highly variable from patient to patient. Background slowing may represent an objective physiologic measure of drug impact on cerebral function and could be useful in monitoring for AED neurotoxicity in individual patients. This would require an intraindividual analysis of AED effects on EEG background rhythms. The present study was designed to develop a methodology for intraindividual analysis of EEG background changes and to apply this methodology to patients beginning or ending chronic AED therapy. EEG recordings were obtained under controlled conditions in 31 healthy subjects and were repeated after an interval of 12-16 weeks. EEG background rhythms from each record were analyzed using the fast Fourier transform, and test-retest differences for several quantitative measures were calculated from each subject's paired recordings. EEG recordings were also obtained in 6 patients beginning or ending chronic AED therapy. Test-retest differences for each patient's quantitative EEG measures were statistically compared with the distributions of test-retest measures obtained from the healthy controls. AED therapy was associated with an increase in absolute delta and/or theta power and a slowing of the dominant posterior rhythm; however, these EEG background changes varied widely in degree from patient to patient. Intraindividual analysis revealed that 5 patients had statistically significant slowing relative to the control group on at least 1 of the 9 target quantitative EEG measures, as well as a composite measure. Statistically significant slowing was also seen as a group effect. The results suggest that among patients undergoing chronic therapy with phenytoin or carbamazepine there are widely different degrees of EEG background slowing, often significantly beyond that expected on the basis of test-retest variability. Intraindividual analysis of the EEG background may be a practical objective measure of a patients unique response to chronic AED therapy.

KW - Antiepileptic drugs

KW - Carbamazepine

KW - EEG frequency analysis

KW - Epilepsy

KW - Phenytoin

UR - http://www.scopus.com/inward/record.url?scp=0028324966&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028324966&partnerID=8YFLogxK

U2 - 10.1016/0013-4694(94)90090-6

DO - 10.1016/0013-4694(94)90090-6

M3 - Article

C2 - 7511500

AN - SCOPUS:0028324966

VL - 90

SP - 186

EP - 193

JO - Electroencephalography and Clinical Neurophysiology

JF - Electroencephalography and Clinical Neurophysiology

SN - 0013-4694

IS - 3

ER -