Evoked Potential Manual: A Practical Guide to Clinical Applications

330 Pages·1983·5.642 MB·English

by  E. Colon, S. Visser, J. de Weerd, A. Zonneveldt (auth.)

EVOKED POTENTIAL MANUAL
EVOKED
POTENTIAL
MANUAL
a practical guide to clinical applications
E. Colon
St. Radboud Hospital, University of I'Jijmegen
The Netherlands
s.
Visser
Free University Hospital, Amsterdam
The Netherlands
J. de Weerd
St. Radboud Hospital, University of Nijmegen, The Netherlands, and
University of Wisconsin, Madison WI, USA
A. Zonneveldt
St. Lucas Hospital, Amsterdam
The Netherlands
1983 Springer-Science+Business Media, B.Y.
IV
Library of Congress Cataloging in Publication Data
Main entry under title:
Evoked potential manual.
Includes bibliographical references and index.
1. Evoked potentials (Electrophysiology) 2. Nervous
system--Diseases--Diagnosis. I. Colon, E.
RC386.6.E86E96 1983 616.8'047547 83-19524
ISBN 978-94-017-1501-0 ISBN 978-94-017-1499-0 (eBook)
DOI 10.1007/978-94-017-1499-0
Copyright
© 1983 by Springer Science+Business Media Dordrecht
Originally published by Martinus Nijhoff Publishers in 1983.
Softcover reprint of the hardcover 1s t edition 1983
All rights reserved. No part of this publication may be reproduced, stored in a
retrieval system, or transmitted in any form or by any means, mechanical,
photocopying, recording, or otherwise, without the prior written permission of
the publishers, Springer-Science+Business Media, B.Y.
PRE.FACE
K. Hecox.
A number of significant challenges confront the clinincian
interested in pathology of the human nervous system. Because
the many components of the nervous system are largely in
accessible to palpation, percussion, auscultation, or direct
visual inspection, the traditional tools of clinical medicine
are restricted in the amount of information they can provide.
The neurologie examination certainly provides essential data
on the integrity of the nervous system, especially with regard
to motor function, but it is increasingly apparent that the
quantitative analysis of dis orders of the human nervous system
requires greater sensitivity and specificity than is achieved
in a routine neurologie examination. The major advances in
imaging procedures (CT scanning, PET scanning, and nuclear
magnetic resonance studiesl are important new sources of in
formation on neural integrity.
Important advances have also occurred in clinical neuro
physiology. The development of single unit recordings in
electromyography, the introduction of quantitative spectral
analysis in EBG recordings, and the growth of sensory evoked
potentials, are three examples of new techniques which provide
previously unavailable information. The development of these
techniques re lies heavily on thechnical advances such as the
increased sophj.stication in electronics, more powerful computer
capabilities, and improvements in amplifier technologies.
The widespread availability of microprocessors and electronic
microcircuitry assures the continued growth and improved
flexibility of recording and stimulating techniques in clinical
VI
neurophysiology. These advances have made new demands on
neurodiagnosticians. The need for familiarity with electronics,
computer sciences, and applied physics, is rapidly increasing.
An understanding of the strengths and limitations cf newer
clinical procedures requires at least some familiarity with
the scientific foundation upon which these procedures are
based.
The need to train residents and re-educate faculty in these
procedures and technologies is apparent. It is in this sense
that this volume is particularly welcome in the clinical
neurophysiology literature. Book outlines several clinical
procedures providing irnportant information on their limitations
and strengths. The authors cornbine clinical and technical
expertise, interfacing the medical and technological aspects
of these procedures. The need for such a manual is apparent
to all concerned with physician and technician training.
Future training manuals must cornbine asound understanding
of the basic sciences underlying clinical neurophysiology
with a broad experience in human neurologie disorders. This
volume represents the successful confluence of these two forces,
and as such sonid represent a heipful addition to the instruc
tional armamentarium of clinical neurophysiologists.
Kurt Hecox, M.D., Ph.D
Associate Professor
Dept. of Faediatrics and Neurology
University of Wisconsin Madison.
ACKNOWLEDGEIJlEN'I'S
We are indebted to Ilse Vermeulen and Vincent van Ammers for preparing
the camera-ready version of this book.
IX
CONTEIIJTS
Preface V
Acknowledgements VII
Contributors XVII
I. IN'TRODUCTION
II. THE l-lEASUREMEN'r OF EVOKED PO'TENTIALS:
TECHNICAL ASPECTS. 11
1 Introduction and summary of this chapter 13
2 General aspects of stimulation 14
2.1 Stimulus repetition rate 14
2.2 Regular versus Irregular stimulation 19
3 . Recording the electrical activity 11
3.1 Recording electrodes 21
3.2 Recording amplifiers 21
3.3 Analog filtering: preliminaries 22
3.4 Analog filtering of evoked potentials 24
4 . Acquisition and processing 29
4.1 Analog-to-digitial conversion 30
4.2 Signal averaging 35
4.3 Artifact rejection 37
5 . Filtering of evoked potentials revisited 38
5.1 Digital filtering 38
5.2 Wave form smoothing 39
5.3 Adaptive digital filtering 41
6 . Analysis and documentation 43
6.1 Identification and labeling of components 43
6.2 Wave form plotting and documentation 45
6.3 Digital wave form storage 46
7 . Evoked Potential Instrumentation 46
7.1 Basic evoked potential system 46
7.2 Periodic inspection and calibration 49
8 . Electrical safety 50
8.1 Safety Standards for equiprnent 50
8.2 Power line safety measures
8.3 Safety in practice 53
x
9 . Interference and artifacts 54
9.1 General provisions for avoiding interference
9.2 Measures for avoiding stimulus artifacts
9.3 Bioelectric and other artifacts 57
10. Further Guidelines for measuring and interpreting
Evoked Potentials 59
10.1 Suggested standard protocols 59
10.2 Acquisition of Duplicate Wave forms 61
10.3 General considerations on normative data
and criteria for abnormality 65
11. Glossary of acronyms 6R
References 70
111. AUDITORY EVOKED POTENTIALS 75
1 Introduction 77
2 Anatomy and physiology 78
2.1 The transducer 78
2.2 The central pathways 80
2.3 Physiology 80
3 . Method of stimulation 84
3.1 Click-stimuli 85
3.2 Burst stimuli 86
3.3 Amplitude modulated stimuli 88
3.4 Frequency modulated stimuli 88
4 . Method of analysis 90
4.1 BAEP 90
4.1.1. Electrode positions 90
4.1.2. Instrumentation 92
4.1.3. Stimulus parameters (clicksl 93
4.1.4. Recording technique 95
4.1.5. Peak detection 96
4.1.6. Identification and differentiation
of the waves 100
4.2 MLAEP 101
4.3 AEP 102
4.3.1. Electrode positions 102
4.3.2. Instrumentation 103
4.3.3. Stimulus parameters 104
XI
5 . Loealization of the various eomponents 106
5.1 BAEP 106
5.2 MLAEP 106
6 . Deseription of the normal auditory evoked
potentials in rean 107
6.1 BABP 107
6.1.1. Morphology 107
6.1.2. Features 109
6.1.3. Parameter assessment 110
6.1.4. Patient parameters 113
6.2 MLAEP 115
6.3 AEP 117
6.3.1. Response properties of the AEP 117
6.3.2. Parameter assessment 118
6.3.3. Reprodueibility 119
6.3.4. Patient parameters 119
7 Normative Values 120
7.1 BAEP 120
7.1.1. Introduetion 120
7.1.2. Our own normative values 120
7.1.3. Comparison of the normative values 122
7.2 MLI\EP 123
7.3 AEP 126
8 . Clinieal use of the auditory evoked potentials' 128
8.1 BAEP and ERA 128
&.1.1. Distinetion between audiologie and
neurologie disorders 128
8.1.2. BAEP and audiometry 130
8.1.3. Standard proeedure determination of
the hearing aeuity 132
8.1.4. Advantages and disadvantages 133
8.1.5. Indieations 133
8.2 BAEP and Neurology 134
8.2.1. ~he pathologieal BAEP 134
8.2.2. Indieations 135
8.3 MLAEP 139
8.3.1. MLAEP in adults 139
8.3.2. MLAEP in infants and ehildren 140
8.4 AEP 140