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Fundamentals of EEG technology. Vol. I. Basic concepts and methods
96
BOOK REVIEWS
interested in the cerebral determinants/correlates of h u m a n psychopathology. BRUCE HERMANN
University of Illinois College of Medicine, Chicago, IL 60612 (U.S.A.)
Fundamentals of EEG technology. Vol. !. Basic concepts and methods. - - F.S. Tyner, J.R. Knott and B. Mayers, Jr. (Raven Press, New York, 1983, 330 p., U.S. $49.50) This text can be highly recommended for those technicians, M.D.s or other students who wish to have a grounding in the basics of EEG technology from a conventional standpoint. The early chapters, on such topics as the EEG instrument, electricity and electronics, electrical safety, electrodes, electrode placement and montages, are dealt with with great care and with obvious understanding of the areas in which beginners run into trouble. In addition they are illustrated by very clear diagrams that are well chosen for their didactic value. The authors make a great and commendable effort in explaining how the 10-20 system works and precisely how you can achieve this placement with accuracy on a particular scalp. This useful kind of detail is rarely seer, in technical accounts. In the classification section of the book th .re is an adequate s u m m a r y of changes during sleep recordings and the complexities encountered in neonatal records. However, in the ~ection on brain death recordings where the d e m a n d s for technicia~ skills are perhaps greatest, virtually no effective guidance is giv~.n concerning such matters as (1) reducing E K G artifact, (2) choice of a non-cephalic monitor, and (3) the problems of the large variety of instrumental artifacts that can be encountered including such practical matters as the ground lead, the disconnection of other monitoring equipment, etc. The topic of artifacts is very well handled apart from the omission of what has been called the ground lead recording (single ended operation of the amplifier) artifact which, in my experience, is still a c o m m o n source of problems in the EEG lab and in any event is a major consideration in the location of the ground lead. There is a down-to-earth evaluation of significant EEG wave forms though perhaps insufficient emphasis on the nasty problem of small sharp spikes and how they are to be differentiated from epileptic discharges. A problem in reviewing this book is that it is stated to be
related to and complementary to the second volume, yet we are given little indication of the latter's content. Thus the strictures in regard to the present volume which I will now list could be markedly influenced (hopefully so) by the contents of the second volume. In regard to the present volume I would be critical on the following grounds: (1) It is 'old fashioned' EEG at a time when the field is showing dramatic change together with suffering the inroads of other technologies. (2) There is virtually no mention of evoked potentials which many people believe to be the salvation of the conventional EEG lab (both intellectual and economic). Again we don't know whether this topic will be dealt with in the second volume but at least some of the general principles which are important in EPs such as the concept of far and near fields receive no mention in spite of the fact that the far field concept probably has significant consequences for the straight EEG. (3) There is no mention of depth electrography even though its findings have really been revolutionary in so far as they reflect on the validity of the surface recorded EEG. Every technician should know that even in the presence of a normal conventional EEG there may be a seizure occurring in the depth. (4) There is a complete exclusion of digital electronic technology even though within the next 5 years instrumental economics will probably make it be the preferred method of EEG recording (by dot printing). Such devices lend themselves with very little additional elaboration to provide an averager so that the likely future functions of an EEG lab, namely doing EEG and evoked potentials would be covered without appreciable extra cost. (5) The remaining aspects of conventional EEG, namely the diagnosis of epilepsy and its modern development, "ambulatory monitoring,' is not mentioned although many labs now employ these techniques. (6) There is no mention of operating room (e.g. endarterectomy) or anesthesia monitoring in spite of the fact that surgeons (under pressure from lawyers) approach their EEG colleagues increasingly for this kind of assistance. In summary, the book is highly recommended for those who desire instruction in the technology of conventional EEG. Others with wider vistas will be inclined to pass it over. Hopefully these problems will be covered in Volume II. R E G I N A L D G. B I C K F O R D
University of California, San Diego, CA 92092 (U.S.A.)
BOOK REVIEWS
interested in the cerebral determinants/correlates of h u m a n psychopathology. BRUCE HERMANN
University of Illinois College of Medicine, Chicago, IL 60612 (U.S.A.)
Fundamentals of EEG technology. Vol. !. Basic concepts and methods. - - F.S. Tyner, J.R. Knott and B. Mayers, Jr. (Raven Press, New York, 1983, 330 p., U.S. $49.50) This text can be highly recommended for those technicians, M.D.s or other students who wish to have a grounding in the basics of EEG technology from a conventional standpoint. The early chapters, on such topics as the EEG instrument, electricity and electronics, electrical safety, electrodes, electrode placement and montages, are dealt with with great care and with obvious understanding of the areas in which beginners run into trouble. In addition they are illustrated by very clear diagrams that are well chosen for their didactic value. The authors make a great and commendable effort in explaining how the 10-20 system works and precisely how you can achieve this placement with accuracy on a particular scalp. This useful kind of detail is rarely seer, in technical accounts. In the classification section of the book th .re is an adequate s u m m a r y of changes during sleep recordings and the complexities encountered in neonatal records. However, in the ~ection on brain death recordings where the d e m a n d s for technicia~ skills are perhaps greatest, virtually no effective guidance is giv~.n concerning such matters as (1) reducing E K G artifact, (2) choice of a non-cephalic monitor, and (3) the problems of the large variety of instrumental artifacts that can be encountered including such practical matters as the ground lead, the disconnection of other monitoring equipment, etc. The topic of artifacts is very well handled apart from the omission of what has been called the ground lead recording (single ended operation of the amplifier) artifact which, in my experience, is still a c o m m o n source of problems in the EEG lab and in any event is a major consideration in the location of the ground lead. There is a down-to-earth evaluation of significant EEG wave forms though perhaps insufficient emphasis on the nasty problem of small sharp spikes and how they are to be differentiated from epileptic discharges. A problem in reviewing this book is that it is stated to be
related to and complementary to the second volume, yet we are given little indication of the latter's content. Thus the strictures in regard to the present volume which I will now list could be markedly influenced (hopefully so) by the contents of the second volume. In regard to the present volume I would be critical on the following grounds: (1) It is 'old fashioned' EEG at a time when the field is showing dramatic change together with suffering the inroads of other technologies. (2) There is virtually no mention of evoked potentials which many people believe to be the salvation of the conventional EEG lab (both intellectual and economic). Again we don't know whether this topic will be dealt with in the second volume but at least some of the general principles which are important in EPs such as the concept of far and near fields receive no mention in spite of the fact that the far field concept probably has significant consequences for the straight EEG. (3) There is no mention of depth electrography even though its findings have really been revolutionary in so far as they reflect on the validity of the surface recorded EEG. Every technician should know that even in the presence of a normal conventional EEG there may be a seizure occurring in the depth. (4) There is a complete exclusion of digital electronic technology even though within the next 5 years instrumental economics will probably make it be the preferred method of EEG recording (by dot printing). Such devices lend themselves with very little additional elaboration to provide an averager so that the likely future functions of an EEG lab, namely doing EEG and evoked potentials would be covered without appreciable extra cost. (5) The remaining aspects of conventional EEG, namely the diagnosis of epilepsy and its modern development, "ambulatory monitoring,' is not mentioned although many labs now employ these techniques. (6) There is no mention of operating room (e.g. endarterectomy) or anesthesia monitoring in spite of the fact that surgeons (under pressure from lawyers) approach their EEG colleagues increasingly for this kind of assistance. In summary, the book is highly recommended for those who desire instruction in the technology of conventional EEG. Others with wider vistas will be inclined to pass it over. Hopefully these problems will be covered in Volume II. R E G I N A L D G. B I C K F O R D
University of California, San Diego, CA 92092 (U.S.A.)