AGNOSIA, APRAXIA AND APHASIA

DISTURBANCES of recognition, voluntary actions and speech have always presented many problems to the examining clinician, and in most cases have been relegated to the diagnostic dustbin under the general term of aphasia by all except those specially interested and trained in neurology. The difficulties and absorbing interests associated with a study of their diverse manifestations are thoroughly presented by Dr. J. M. Nielsen' in his recently published monumental work on these subjects. This book is much more than a second edition of its predecessor, which was like a monograph, and it contalns full and detailed statements of the evidence on which the author's earlier conclusions were based. The author has also propounded a new nomenclature, which, even if somewhat cumbersome and cluttered up with adjectives, at least has the merit of being based on the anatomy and physiology of speech, reading and writing, and other skilled actions. After an excellent historical review of observations upon the disturbances under consideration, in which due homage is paid to such famous neurologists of the European and British schools as Broca, Charcot, Marie. Hughlings Jackson and Head, among many others, there follows a chapter in which the author outlines his concepts of eugnosia, eupraxia and euphasia, the normal precursors of the pathological states of agnosia, apraxia and aphasia. The psychological, physiological and anatomical aspects of all three conditions are fully explained, and their values In cerebral localization confirmed from conclusions drawn from special cases selected out of the larger number described In detail later on. A plea is entered for the retention of some of the old terms, such as asemie, asymbolie, asemasia, aphemia and avocalia, but the author states that the three terms already mentioned have become so universal that this Is now impracticable. His concepts are, on the whole, well and logically presented so that by the time this chapter has been read and digested, the reader should have clearly crystalized his Ideas on the mechanisms of perception and recognition of objects, the accomplishment of purposeful movements, speech, reading and writing, and be ready to absorb the explanations and classifications of the corresponding pathological states described In the next three chapters on the agnosias, apraxlas and aphasias, and to understand their localizations, according to the numerical cyto-archltectonic areas of Brodrnann. The agnosias are divided broadly Into visual (mind blindness) and acoustic varieties, and the apraxias, Into kinetic, ideokinetic and ideational types. With the aphasias, the author claims to have been the first to differentiate them into lower and higher levels. The former contain the two major categories of motor and sensory aphasia with their numerous sub-varieties, and are described as "disturbances of recall". that is, reminiscence. They are the opposite concepts to disturbances of recognition. The latter is the hierarchy of semantics (semantic aphasia of Head) and calculations, and involves the powers of comprehension. Next follows a short but very interesting chapter on what the author calls the "Body Scheme", a term used to designate the concept a person has of his own body, its parts and their relations to each other. The clinical features of focal lesions causing defects In this sphere, as they affect either the major (usually left) hemisphere or the minor (usually right) hemisphere. are described clearly, and explain many of the extraordinary localized defects encountered during wartime from bullet and shrapnel penetrating wounds of the brain. Gerstman's syndrome of "finger agnosia, confusion of right and left sides, acalculia and agraphia" Is a particularly fascinating example, even If the name applied to the first portion of the syndrome, namely, visual autotopagnosia, is somewhat alarming; and a difference may extst between loss of recognition for animate as against inanimate objects. Another interesting disturbance of the "body scheme" is described as anosognosia, a denial of one's own hemiplegia usually from a lesion on the minor side; and attention is drawn to the confabulations adopted by some patients to cover up defects of both visual and auditory blindness and deafness. After a short section on methods of examination, the rest of the book is devoted to a detailed presentation of the case histories and their post-mortem findings, where available, on which the "evidence" for the author's numerous