cases, in addition to a diseased state of the olivary bodies, there was extensive disease in other parts, they cannot be looked upon as substantial evidence in favour of the localisation of speech in the corpora olivaria; in fact, Cruveilhier, who was the author of all the cases which I have quoted from Van Der Kolk's work, was quite innocent himself of drawing from them any inference as to the connexion of the olivary bodies with the articulation of words.* The next theory for consideration is that of M. Bouillaud, who places the seat of speech in the anterior lobes, and who, twenty years ago, offered a prize of 500 francs for any well authenticated case negativing his views. Although this theory has met with less opposition than the others, several cases have been recorded, which, to say the least, throw considerable doubt upon its truth. Let us see what evidence the previous pages of this essay furnish for or against the views of M. Bouillaud, who, it must be remembered, admits that speech may exist with one frontal lobe destroyed, but who maintains that when both are destroyed or seriously damaged, articulate language becomes impossible. * Since the above was penned, my attention has been called to the latest publication on the anatomy of the medulla oblongata in this country, in which the author, Dr. Lockhart Clarke, mentions two cases of aphasia, in each of which one of the olivary bodies was diseased, being in the one case atrophied, and in the other the seat of a former clot. In both these instances there were numerous and extensive lesions in other parts of the brain, therefore-as Dr. Clarke also admits -they by no means prove that the loss of speech was due to the diseased condition of the olivary bodies.-"Researches on the Intimate Structure of the Brain." Philosophical Transactions 1868, Pt. I., p. 312. I have quoted three cases* in which both anterior lobes were destroyed or very extensively injured. What does a conscientious analysis of them teach us? In M. Peter's case we have seen that speech was preserved, although both frontal lobes were reduced to a pulp (réduits en bouillie); in one of M. Trousseau's cases, a ball had traversed the two frontal lobes at their centre, entering at one temple and making its exit by the other, articulation remaining unimpaired during the six months the patient survived this fearful injury; in M. Velpeau's celebrated case a scirrhous tumour had replaced the two anterior lobes; but instead of being speechless the man was remarkably loquacious.† These three cases, to which I could add others, seem to upset M. Bouillaud's doctrine by showing that a profound lesion may exist in both anterior lobes, without impairment of articulate language; but on the other hand, it is only fair to observe that in none of them was there positive evidence of the complete destruction of the anterior lobes, for in M. Peter's case, although the lesion must have been extensive, still, as the words "cornes frontales" are used to describe the * Vide Part I., pp. 14, 18, 19. It is well known that tumours of the brain, by their slow and gradual development, frequently compress, deform, and displace the cerebral tissue, without sensibly altering the function of that organ; and it has been suggested, that in these cases there may be a sort of unfolding of the brain tissue by the pressure of the tumour which has developed itself in its place, but not at the expense of the tissue itself, which, in its new relations, and under the form and volume to which it has been reduced, may still retain the integrity of its structure, and its habitual functional aptitude. I need scarcely add, that this explanation cannot apply to the cases I have quoted, in which integrity of speech coincided with tumours involving nearly the entire anterior lobe. part injured, the posterior part of the same lobes may possibly have remained unaffected; again, in M. Trousseau's case it is possible to conceive that the transit of a ball through both anterior lobes may have left a portion of the cerebral substance uninjured; in reference to M. Velpeau's barber, in reading carefully the details of the autopsy as noted in the Bulletins de l'Académie de Médecine, I find it stated that a portion of the right anterior lobe was not involved in the tumour, also that at the posterior, external, and inferior part of the left lobe, there was a certain thickness of cerebral substance unimpaired. The adversaries of the localisation of speech in the anterior lobes have attached an immense importance to a case mentioned by Cruveilhier of a congenital idiot, who could pronounce words distinctly articulated, although after death it was found that there was congenital absence of the two anterior lobes. This observation has such an important bearing upon our present inquiry, that an abridgement of it must find a place here. Alexandrine Vaillosge, a congenital idiot, came under observation at the age of twelve-the idiocy being carried to the highest degree. She could neither dress nor feed herself; although she could move her limbs in all directions, she was unable to co-ordinate her movements for the act of walking, and it was necessary to carry her from place to place. The sense of smell seemed not to exist, or rather the young idiot was insensible to bad odours; the other senses presented nothing remarkable. If one threatened to strike her she would make the most frightful noises. The desire for food was readily felt, and when hungry she would express her wants by means of words very distinctly articulated. This girl having died at the age of fifteen of chronic diarrhoea, the following post-mortem appearances were observed:-The skull was very well formed exteriorly, but its cavity was not completely filled by the brain. The anterior lobes were entirely absent, and a limpid serum contained in the cavity of the arachnoid occupied the space which separated the anterior extremity of the brain from the frontal portion of the dura mater. Strange to say, the orbital plates, although not in contact with the brain, but with serum, presented the mammillary eminences and digital impressions exactly similar to those of a healthy individual of the same age. With the exception of the absence of the anterior lobe, the left hemisphere completely filled the corresponding part of the skull; the right hemisphere, the size of which was only about half that of the left, was separated from the parietes of the skull by a space filled with serum.* Cruveilhier himself seems to have considered this case as fatal to the doctrine of the localisation of speech in the anterior lobes; on examining, however, carefully the beautiful plate annexed to the description of this case, it is evident that when the author stated that the two anterior lobes were wanting, he did not limit these lobes in the same way that we do now. For Cruveilhier, the anterior lobes were limited inferiorly to that part of the hemisphere which lies on the root of the orbit,† for a glance at the plate will show that only the anterior half of the left frontal lobe was destroyed; the transverse frontal convolution was preserved, as well as the posterior half of the 1st, 2nd, and 3rd frontal convolutions; although the disease in the right hemisphere was more extensive, still the plate shows that a considerable portion of it still remained. According, therefore, to our present mode of dividing the brain, this case cannot be cited as impugning M. Bouillaud's theory. * Cruveilhier, Anatomie Pathologique, 8e Livraison, pl. 6. + This limitation of the anterior lobe is correct only as far as the orbital convolutions are concerned, for a glance at the plate, forming frontispiece to this essay, will show that above the orbital portion the anterior lobe extends very much further backwards. I now pass to the consideration of the theory of M. Dax. The brain as a whole has hitherto been considered as a symmetrical organ, even by those who regarded it as an assemblage of lesser organs arranged in pairs with corresponding functions; M. Dax, however, assigns a function to the left hemisphere, which, according to him, is not shared by the right, for he places the lesion in aphasia solely in the left hemisphere, without however limiting it to any part of that hemisphere.* This is a question that can only be settled by a careful statistical research. M. Broca estimates the proportion of aphasics with lesion in the right hemisphere as 1 in 20. In 1864, M. Vulpian tabulated all the cases bearing upon this question which came under his observation at the La Salpêtrière. They were twelve in number, and divided as follows:-Lesions of the left anterior lobe with aphasia, 5; lesions of the left anterior lobe without aphasia, 4; lesions of the right anterior lobe without aphasia, 1; cases of aphasia without lesion of either anterior lobe, 2. Amongst the 63 cases I have recorded in the first three parts of this essay, in 32 only there was hemiplegia, the paralysis occurring 21 times on the right side and 7 times on the left, whilst in 4 instances the side was not stated. It will be remembered that M. Dax's paper contained 140 obser * Dr. Dax's conclusions were embodied in a communication to the medical congress held at Montpellier in the year 1836, the title of his paper being-Lésions de la moitié gauche de l'encéphale coincidant avec l'oubli des signes de la pensée. In 1863 his son, Dr. G. Dax, presented a memoir to the Academy of Medicine of Paris, in which, whilst supporting the views of his father as to the seat of speech in the left hemisphere, he confined it to more narrow limits, namely, the anterior and external part of the middle lobe. |
