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Blindness and the Electrical Activity of the Brain: Electroencephalographic Studies of the Effects of Sensory Impairment
VOL. 79, NO. 6
BOOK REVIEWS
change precludes the need to install a hemi spheric bowl for ganzfeld stimulation within the shielded enclosure where testing is con ducted. Formerly, we presented the stimulus light in Maxwellian view (light focused in the plane of the pupil) via fiber optic wave guides and condensing lenses. The loss of light intensity by the fiber optic system is considerable. The stimulus efficiency is in creased by making the above change. JEROME T. PEARLMAN,
M.D.
Los Angeles, California
BOOK REVIEWS OPHTHALMIC MANIFESTATIONS OF SYSTEMIC VASCULAR DISEASE. MAJOR PROBLEMS IN
vol. 3. By David G. Cogan. Camden, New Jersey, W. B. Saunders, Co., 1974. Clothbound, 187 pages, table of contents, bibliography, 118 black and white figures. $11
INTERNAL MEDICINE,
This is the third volume of a series of 24, edited by Lloyd H. Smith, Jr. A list of the subject matter of future volumes is printed opposite the title page and it includes a variety of disorders. The editor could not have selected a more qualified author to write volume 3, and the results are excellent. Systemic vascular dis ease so commonly involves the ocular struc tures that this text should be valuable to all medical disciplines concerned with any phase of vascular abnormalities. Although the text comprises only 154 pages with 118 illustrations, there is an ex tensive bibliography of 709 references. The descriptions of the ocular manifestations in general are brief but complete and are ref erenced toward further reading. The index is detailed. The illustrations are of unusual clarity. The nine chapters, each further subdivided are: External ocular signs, Fundus, Sig
1057
nificance of fundus signs, Subjective symp toms and visual field abnormalities, Fundus signs of systemic vascular disease, Occlusive arterial disease in the eye, Occlusive venous disease in the eye, Vasculitis, and Neuroophthalmic complications of intracranial vascular disease. Each chapter closes with a summarizing section. There is little to criticize adversely in this textbook for it is written in the clear and concise style that characterizes Dr. Cogan's previous works. The technique of ophthalmodynamometry in Figure 22 portrays the application of the instrument to the nasal sclera, which is cumbersome and inaccurate. Application to the lateral sclera is the normal method. Furthermore, the Bailliart dial ophthalmodynamometer shown in the same illustration is the most inaccurate and least reliable of the available models. Figure 65 shows a typical fibrin-platelet embolus at a fork of a retinal arteriole but labeled retinal arteriosclerosis. In Figure 88, a calcine or fibrin-platelet embolus lodged in the fork of the central retinal artery in the center of the optic disk is disregarded as the cause of occlusion of the central retinal ar tery. But these are minor exceptions, in an otherwise fine book, recommended not only for ophthalmologists but anyone concerned with systemic vascular disease. ROBERT W .
HOLLENHORST
BLINDNESS AND THE ELECTRICAL ACTIVITY OF THE
BRAIN:
ELECTROENCEPHALOCRAPHIC
STUDIES OF THE EFFECTS OF SENSORY IM
By L. A. Novikova. New York, American Foundation for the Blind Inc., 1974. Paperbound, 341 pages, table of con tents, bibliography, 144 black and white figures. $5.75 PAIRMENT.
In the early days of electroencephalography, there was often the question as to
1058
AMERICAN JOURNAL OF OPHTHALMOLOGY
whether the electrical activity recorded from the surface of the human scalp was from the brain, or the elevator down the hallway. EEG researchers now feel confident that this activity is from the brain. Certain struc tures within the brain have been shown to be intimately involved in the generation of on going cortical activity. The physiologic mech anisms of the EEG and its relationship to cortical processes, however, remain elusive. In the jargon of the trade, further studies are necessary before these factors are understood. In this respect, the monograph by L. A. Novikova is an important contribution. The work presented in this book represents near ly two decades of study by Novikova and his colleagues at the Institute of Defectology in Moscow on the EEG under conditions of sensory impairment. The first part of the book is devoted to studies of the EEG in patients with periph eral visual and auditory disorders. Data pre sented in this section relate changes in the amplitude, frequency, and spatial distribu tion of the EEG to the degree, duration, and nature of the peripheral sensory disorder. Based on these data, the author formulates the hypothesis that changes in the EEG in visual impairment reflect the development of compensatory cortical processes. This com pensation is manifested as an overall decrease in the amplitude of the EEG, as well as a shift of focus to the somatosensory area with a concomitant change in its frequency to the Rolandic rhythm. Novikova relates these find ings to a "sharpening" of the preserved so matosensory processes in these patients. In the second part of the book, the author demonstrates the importance of these find ings in the diagnostic use of the EEG in pa tients with both visual and nonvisual, neuro logic disorders. The author points out that diagnostic application of the EEG can be made only if changes in the EEG resulting from visual impairment are taken into ac count. The last part of the book presents experi mental data intended by the author to eluci
JUNE, 1975
date the physiologic mechanisms underlying the EEG changes observed in patients. In studies on both functionally and anatomically visually deafferented rabbits, Novikova shows that these changes are due to a number of complex interrelationships between cortical and subcortical structures. In particular, both the inhibitory influences of the cortex on subcortical structures, and the excitatory influ ences of subcortical structures on the cortex appear to play a major role. Although the book appears intended for neuroscientists active in basic research into the mechanisms of the EEG, it will inter est ophthalmologists using electroencephalographic measurements in the diagnosis of vi sual disorders and the assessment of visual function. J O H N L. TRIMBLE
LASER APPLICATIONS IN MEDICINE AND BIOL
OGY, vol. 2. Edited by M. L. Wolbarsht. New York, Plenum Publishing Corpora tion, 1974. Clothbound, 404 pages, table of contents, index, 172 black and white figures. $27.50 Volume 2 of this text, edited by M. L. Wolbarsht, should be useful for the ophthal mologist interested in the specific applications of lasers to ophthalmology and to the broader use of lasers in general medicine and biology. The chapters by Hochheimer on lasers in ophthalmology and by Vaughan, Laing, and Wiggins on holography of the eye are of special interest to the ophthalmologist. These two chapters are well written and give clear and concise explanations of the somewhat technical and complex subject matter. For the research-oriented investigator, the other topics are well selected and prepared. Of particular interest to all research investi gators working with lasers is the chapter by Sliney on laser protective eyewear. I was not aware of all the applications of lasers in clinical surgery and found the chapter by Caplan and co-workers on carbon dioxide
BOOK REVIEWS
change precludes the need to install a hemi spheric bowl for ganzfeld stimulation within the shielded enclosure where testing is con ducted. Formerly, we presented the stimulus light in Maxwellian view (light focused in the plane of the pupil) via fiber optic wave guides and condensing lenses. The loss of light intensity by the fiber optic system is considerable. The stimulus efficiency is in creased by making the above change. JEROME T. PEARLMAN,
M.D.
Los Angeles, California
BOOK REVIEWS OPHTHALMIC MANIFESTATIONS OF SYSTEMIC VASCULAR DISEASE. MAJOR PROBLEMS IN
vol. 3. By David G. Cogan. Camden, New Jersey, W. B. Saunders, Co., 1974. Clothbound, 187 pages, table of contents, bibliography, 118 black and white figures. $11
INTERNAL MEDICINE,
This is the third volume of a series of 24, edited by Lloyd H. Smith, Jr. A list of the subject matter of future volumes is printed opposite the title page and it includes a variety of disorders. The editor could not have selected a more qualified author to write volume 3, and the results are excellent. Systemic vascular dis ease so commonly involves the ocular struc tures that this text should be valuable to all medical disciplines concerned with any phase of vascular abnormalities. Although the text comprises only 154 pages with 118 illustrations, there is an ex tensive bibliography of 709 references. The descriptions of the ocular manifestations in general are brief but complete and are ref erenced toward further reading. The index is detailed. The illustrations are of unusual clarity. The nine chapters, each further subdivided are: External ocular signs, Fundus, Sig
1057
nificance of fundus signs, Subjective symp toms and visual field abnormalities, Fundus signs of systemic vascular disease, Occlusive arterial disease in the eye, Occlusive venous disease in the eye, Vasculitis, and Neuroophthalmic complications of intracranial vascular disease. Each chapter closes with a summarizing section. There is little to criticize adversely in this textbook for it is written in the clear and concise style that characterizes Dr. Cogan's previous works. The technique of ophthalmodynamometry in Figure 22 portrays the application of the instrument to the nasal sclera, which is cumbersome and inaccurate. Application to the lateral sclera is the normal method. Furthermore, the Bailliart dial ophthalmodynamometer shown in the same illustration is the most inaccurate and least reliable of the available models. Figure 65 shows a typical fibrin-platelet embolus at a fork of a retinal arteriole but labeled retinal arteriosclerosis. In Figure 88, a calcine or fibrin-platelet embolus lodged in the fork of the central retinal artery in the center of the optic disk is disregarded as the cause of occlusion of the central retinal ar tery. But these are minor exceptions, in an otherwise fine book, recommended not only for ophthalmologists but anyone concerned with systemic vascular disease. ROBERT W .
HOLLENHORST
BLINDNESS AND THE ELECTRICAL ACTIVITY OF THE
BRAIN:
ELECTROENCEPHALOCRAPHIC
STUDIES OF THE EFFECTS OF SENSORY IM
By L. A. Novikova. New York, American Foundation for the Blind Inc., 1974. Paperbound, 341 pages, table of con tents, bibliography, 144 black and white figures. $5.75 PAIRMENT.
In the early days of electroencephalography, there was often the question as to
1058
AMERICAN JOURNAL OF OPHTHALMOLOGY
whether the electrical activity recorded from the surface of the human scalp was from the brain, or the elevator down the hallway. EEG researchers now feel confident that this activity is from the brain. Certain struc tures within the brain have been shown to be intimately involved in the generation of on going cortical activity. The physiologic mech anisms of the EEG and its relationship to cortical processes, however, remain elusive. In the jargon of the trade, further studies are necessary before these factors are understood. In this respect, the monograph by L. A. Novikova is an important contribution. The work presented in this book represents near ly two decades of study by Novikova and his colleagues at the Institute of Defectology in Moscow on the EEG under conditions of sensory impairment. The first part of the book is devoted to studies of the EEG in patients with periph eral visual and auditory disorders. Data pre sented in this section relate changes in the amplitude, frequency, and spatial distribu tion of the EEG to the degree, duration, and nature of the peripheral sensory disorder. Based on these data, the author formulates the hypothesis that changes in the EEG in visual impairment reflect the development of compensatory cortical processes. This com pensation is manifested as an overall decrease in the amplitude of the EEG, as well as a shift of focus to the somatosensory area with a concomitant change in its frequency to the Rolandic rhythm. Novikova relates these find ings to a "sharpening" of the preserved so matosensory processes in these patients. In the second part of the book, the author demonstrates the importance of these find ings in the diagnostic use of the EEG in pa tients with both visual and nonvisual, neuro logic disorders. The author points out that diagnostic application of the EEG can be made only if changes in the EEG resulting from visual impairment are taken into ac count. The last part of the book presents experi mental data intended by the author to eluci
JUNE, 1975
date the physiologic mechanisms underlying the EEG changes observed in patients. In studies on both functionally and anatomically visually deafferented rabbits, Novikova shows that these changes are due to a number of complex interrelationships between cortical and subcortical structures. In particular, both the inhibitory influences of the cortex on subcortical structures, and the excitatory influ ences of subcortical structures on the cortex appear to play a major role. Although the book appears intended for neuroscientists active in basic research into the mechanisms of the EEG, it will inter est ophthalmologists using electroencephalographic measurements in the diagnosis of vi sual disorders and the assessment of visual function. J O H N L. TRIMBLE
LASER APPLICATIONS IN MEDICINE AND BIOL
OGY, vol. 2. Edited by M. L. Wolbarsht. New York, Plenum Publishing Corpora tion, 1974. Clothbound, 404 pages, table of contents, index, 172 black and white figures. $27.50 Volume 2 of this text, edited by M. L. Wolbarsht, should be useful for the ophthal mologist interested in the specific applications of lasers to ophthalmology and to the broader use of lasers in general medicine and biology. The chapters by Hochheimer on lasers in ophthalmology and by Vaughan, Laing, and Wiggins on holography of the eye are of special interest to the ophthalmologist. These two chapters are well written and give clear and concise explanations of the somewhat technical and complex subject matter. For the research-oriented investigator, the other topics are well selected and prepared. Of particular interest to all research investi gators working with lasers is the chapter by Sliney on laser protective eyewear. I was not aware of all the applications of lasers in clinical surgery and found the chapter by Caplan and co-workers on carbon dioxide