Lectures upon the Structure and Diseases of the Nervous System
This interesting little brochure is composed of a course of lectures on the Structure and Diseases of the Nervous System, delivered by M. Luys, the well-known physician of La balpetriere. M. Luys, though not attached to the Ecole de Medecine of Paris eithei as a professor or an extra-mural lecturer, is rapidly acquiring a great repu- tation as a teacher, and has already obtained a wide celebrity from liia * Logons sur la Structure et les Maladies du Systeme JServeux. Par J. Luys, Medecin de la Salpetriere, Laurent do l’lnstitut (Academic des Sciences), de l’Academie de Medecine, et de la Faculte do Medecine. Recueillies par J. I)avo, Interne du Service. Bailliere, Tindall & Cox. King William Street, Strand. admirable researches on the cerebrospinal nervous system and his photographic iconography of the nerve centres. His aim in teaching is to initiate his pupils little by little into the great questions of cere- bral activity, in its ensemble, and thus by degrees give them precise formula? of the different operations both of psychological and intel- lectual life, the phenomena of which have been but too little studied by our professional brethren. The mysteries of psychology form the most seductive and attractive studies of human science, whilst they are also the most obscure, undecided, and most open to discussion.
All his efforts tend to show that the varieties of mental maladies derive their origin in a material lesion of the nerve centres, and that there is a natural and constant connection between the regular acts of an active healthy brain, and the different functional deviations in insanity. M. Luys first treats of his mode of preparing morbid specimens for examination, and the various sections most useful for a careful study of the brain. After an exhaustive description of the structure of the cortical grey matter, he shows the direction of the fibres of the white matter, and divides them into two classes: (a) Those having a radiating and converging direction, he terms the converging system; (b) And those uniting the two halves of the cerebrum and forming the corpus callosum, the commissurant or anastomotic system. From his physical examination of the pathological conditions of the cortical structure, we are told that partial atrophy of certain convolutions is the pathological condition in paralytic dementia.
M. Luys now considers the pathological anatomy of the convolu- tions. He lays great stress upon what he deems to be the principal character of the structure, viz. : (1) the stratification of the cells into distinct zones; (2) the lateral anastomoses between the cells of each zone, and anastomoses between the successive zones; (3) the distribu- tion of small cells in the superficial, and of the large cells in the deeper zones. From these and other anatomical facts as to the disposition of the cells and fibres, he makes the following physiological deductions. Each zone plays a particular role and possesses functions peculiar to it; and, though the present state of science does not enable us to limit in an exact manner the special attributes of any particular order of cells, still, by comparing them with the elements of the spinal cord, we can already make certain legitimate inductions relative to their diverse activities. The large cells correspond to the large cells found in the anterior cornua of the spinal cord, whilst the small superficial cells bear a certain analogy to the small cells of the grey matter. The superficial zones, then, may be considered as disseminating the impres- sion of general sensibility (as the sensorium commune) and the deeper zones as the origin of motor impulses. These deductions are of course but mere hypotheses more or less rational, still they are well supported by the experiments of Flourens, Louget, Schiff, and Ferrier.
The various pathological conditions of the cortical matter are next carefully described, and the lesions of the vessels and cells treated at considerable length.
The white matter is carefully described, especially as to the di- rection and functions of the commissurant and convergent systems of fibres. The corpus callosum he treats as a physiological as well as an anatomical commissure, and its absence he identifies with congenital idiocy.
The description o? the thalami optici (couche optique) forms the most original, if not the most instructive part of the book. The corpus album subrotundum of Arnold and the other two ganglions he names the anterior, middle (moyen) and posterior centres, and to these he adds a fourth which he himself has discovered?the median centre. He gives them each a second name, descriptive of their iunctions. The anterior centre, from its connection with the tcenia semi-circularis and the olfactive impressions, is called the olfactive centre. The centre moyen receives the nerve fibres of the second pair, hence the name of optic centre. The centre median, from its close relation to the sensitive fibres of the convergent system, is termed the centre of general sensibility. The posterior centre plays an important role in the pei’ception of sounds, hence the name ot acoustic centre. In support of the physiological deductions made in these chapters, he cites several pathological facts, grouj^ed under three exhaustive heads: (1) anatomo-pathological proofs; (2) proofs of experimental physiology; (3) clinical proofs. The latter proves, in the most irrefutable manner, that the optic thalami receive, preserve, and trans- form the sensorial impressions previous to their definitive irradiation to the cortical periphery. The Iunctions of the optic thalami, in their relation to intellectual alimentation, are not inaptly compared to those of the mouth in receiving and preparing the alimentary bolus before it passes into the stomach.
The description of the brain is now concluded with a careful account of the corpus striatum. He regards the corpus striatum as the centre of the reception, regulation, and elaboration of voluntary motor impressions emanating from the deep layers of the cortical matter. The pathological facts confirmatory of this theory are divided into two classes : (1) Those in which a destruction of the corpus striatum has resulted in motor paralysis, with preservation of intelligence, more or less complete, according to the extent of the lesion; (2) those in which its functions have not been destroyed, but merely obstructed by a compression or partial degenerescence of the elements, entailing certain disorders in the motor sphere.
M. Luys concludes by attempting to elucidate the most complex of all motor phenomena?the action of emitting articulate sounds. The act of speech differs from the other modes of expression, firstly, in not being the movement but merely the result of the movement Avliich makes us aware that the order of the will has been executed; and secondly, because in the phono-motor apparatus, though composed of two symmetrical halves like the rest of the body, they are not distinct so far as their functions are concerned. The bilateral integrity of the appa- ratus is a sine qua non of the perfect exercise of verbal functions. This part of the work seems unfinished, and is rather obscure, though we might expect this when we consider the difficulties to be encoun- tered.
We have a specimen of M. Luys’ ability as a photographer in the five illustrations, dissections of the optic thalami. With the introduction of photo-mechanical printing a new era in book illustra- tion has begun, and Ave hope soon to see our medical text-books illustrated without the intervention of the draughtsman or “wood engraver.
In conclusion, though we do not agree with all M. Luys’ deduc- tions, we can certainly recommend everyone interested in the elucidation of the mysteries of psychology to read the book carefully, and if possible, by original research, to contribute his mite to the grand end and object which the talented author has in view. We shall look forward with pleasure to the next work from the fertile pen of M. Luys.
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