Microcephalism. Brains of an Imbecile
279 Art. IX.?.
A girl, aged 18, of undeveloped intelligence and ineducable was sent as a lierd by her parents into the woods, where she became pregnant by a shepherd. Sent to the Hospital de la Pitie, in Paris, she died twenty days after her accouchement. The Brain of the deceased presented the following charac- teristic peculiarities :?The simplicity, the size, and the smooth- ness of the convolutions recalled those in the brain of the Hot- tentot Venus.
Certain of these anomalies are to be attributed to the arrestment of development; for example, the Fissure of Sylvius gaped so much that the Lobule of the Insula was exposed, such as is presented in a full-grown foetus. But there were other peculiarities which could not be so classed, such as the abnormal size of certain convolutions, and especially of the cerebellum, the small size of others, and the marked development of the perpendicular fissure, which are not presented in the foetus, but in the brain of the anthropoid apes.
The author styles these simply ” indications of reversion,” and, recoiling from all hypothesis, confines himself to the fol- lowing conclusions.
” 1. That the weight of the brain, while it must be taken into account, must not be regarded as a measure of intelligence, as there must be likewise considered whatever data may be furnished by morphology and by microscopical investigation.
” 2. The morphology of the convolutions is all important, as the congenital obtuseness of the intelligence corresponds almost invariably with the simplicity of these organs. ” 3. Such simplicity appears to proceed from arrestment of development.
” 4. Certain such morphologic conditions admit of no. other interpretation ; these constitute an abnormal arrangement both at the foetal and adult age of the human species, and are normal in the lower animals.
” In other terms, there may be structural deviations by mere arrestment, or by irregularity of development.” M. Broca comments on these observations, that the amount of development is the only difference between the brain of man and that of the anthropoid apes. But according to M. Topinard the difference of the quantity of the respective brains is enormous, so that the gap between man and the animals most closely resembling him in structure is very great. Thus the gorilla and man, otherwise more closely resembling each other, present in the former a mean cranium capacity of 500 centi- metres cubes, and in the latter of 1,500 centimetres cubes in round numbers, or a difference of one to three. MEXICAN MICROCEPHALES. AZTECS. On the presentation of two Mexican Microcephales who had been exhibited in Paris nineteen years ago, and who now, although somewhat developed, were still idiots, a discussion arose in the Anthropological Society as to whether the micro- cephalic condition depended on the premature closing of the sutures of the skull, or upon the arrestment of the development of the brain itself, when it was proposed that as individuals very closely resembling those under examination were to be found in asylums, steps should be taken to secure from the medical men of these institutions facts, photographs, &c., which might throw light on the subject under investigation?a project which, although not effectively carried out, might be resumed with valuable results. Full descriptions and representations of the Aztecs now alluded to are to be found in the Bulletin Anthropologique, 1875, which it may be interesting to com- pare with the observations published when these idiots made their first tour in Europe twenty years ago, and for which we are indebted to Darren, in America; Richard Owen and Conolly, in England; Saussure, Jules Guerin, and Baillarger, in France ; Carus and Leubuscher, in Germany, &c. &c.
M. Hamy has arrived at the conclusion that such micro- cephales are the issue of a connection between the Indian and the Negro, in which the former element preponderates, and, without speculating more profoundly as to their origin, he detects in them a striking resemblance to the bas-reliefs sculp- tured on the ruins of Palemque (Mexico), which have been regarded as the figures of idiots and microcephales, formerly objects of worship; in the same way as imbeciles and lunatics were superstitiously looked upon in Europe.
[Another theory has been propounded, to the effect that the bas-reliefs seen in the colossal temples in South America repre- sented the monarchs or rulers of a tribe bearing the name of Aztecs, dwarfed or degenerated by luxury; or it might be by aititicial means, and then commemorated as objects worthy of honour and respect, if not of adoration.?Ed.]
M. Mierzejewski, St. Petersburg, gives-the account of a microcephale examined by him, who during his life of 50 years vegetated in a state of moral and physical apathy, never dis- playing more intelligence than an infant eighteen months old. The weight of the brain was only 369 grammes, standing in proportion to the body as one in 250, regarded by the nar- rator as the lowest weight as yet recorded by science. The shape of the brain, the disposition of the convolutions of the Fissure of Sylvius, and of the Frontal and Parietal Lobes, resembled that of a human foetus of nine months or less.
The microscope showed that the grey substance preserved its nervous elements and interstitial structure in their normal state and relations.
M. M. remarks that the central lobes were obviously the smallest, and that in them consequently the arrestment of development was most conspicuous. These parts are known to contain the largest cellules of the circonvolutions which have been considered as essentially motor centres. At this point it might be demanded whether to the non-development of those lobes and their contained cellules might be attributed that apathy by which the idiot was characterised. In connection with the latter observation, M. M. adduces the case of another microcephale in whom the central lobes were prodigiously developed, and who was remarkable for his restlessness and mobility.
WEIGHT OF MICROCEPHIC BRAINS.
In a microcephale, who died set. two years and three months, examined by MM. Grueniot and Broca, whose complete brain with membranes weighed only 406 grammes, but in which atrophy was most marked in the right cerebral hemisphere, which weighed 52 grammes less than the left ; the parietal region of the cranium presented a depression corresponding to the most atrophica] part of the brain, consequently the cerebral atrophy had been the primary phenomenon; furnishing an additional fact in opposition to the theory of Vogt and Virchow that the premature closures of the sutures is the cause of the non- development of the brain.
M. Broca has likewise described an infant, aged 3^ months, born with an imperforate anus, the rectum opening obliquely into the vagina. The infant being in great danger, an opera- tion was performed without success. The cranium of this child was excessively small, the brain weighed only 104 grammes. This is the smallest weight ever observed in a child born alive, and is five times less than what generally exists in a child tour months old.
This minute brain did not occupy the whole of the cavity of the skull, the intervening space being filled up with a compen- satory cerebro-spinal fluid. The anomalies in the brain-sub- stance were numerous, but they did not correspond to any stage of the ordinary evolution in man or animals.
ARTIFICIAL DEFORMATIONS OF SKULL.
Microcephalism is not the only cranian anomaly to which the attention of scientific men has been directed. Discussion has often arisen as to the artificial as well as the pathological deformities of the skull. The former are especially prevalent in savage and uncurbed populations, especially in North and South America, and in the meridional portions of these regions, such as Peru. Moridiere has recently noted them among the Anamites.
Not merely in antiquity and in remote countries, but even at home, a somewhat similar practice has been described by MM. Foville, senr., Delaye, and Lunier, when pointing out the process by which nurses in Normandy, Toulouse, and the Deux-Sevres, surround and compress the heads of newly born children with bandages.
[In a work devoted to this subject M. Foville gives illus- trations of the extent to which those appliances influence the shape and contour of the whole head or certain of its regions. We have been assured that in the northern parts of our own country similar artificial interference with the growth of the head was resorted to at 110 distant date, although the deformity was neither so great nor so grotesque as are the cases repre- sented by our French authority.?
M. Broca has recalled these observations when examining a cranium sent to him from the Hotel Dieu at Rouen, at the same time stating that alienists had denounced the practice of interfering with the development of the head not merely on the ground of the hideous malformation at once produced, but of the intellectual disturbance and disease which followed. He likewise referred to a certain number of the crania of very young children in which the bones appeared worm-eaten or par- tially unossified at the very points corresponding to the position of the bandages, but added that the exposure and remonstrances by medical men had contributed to diminish such injurious practices. M. Parrot has observed that cranial deformity may 1 e attributed to two causes: first, from the custom of placing infants always in the same position and generally on the right side, which determines the flattening and depression of the frontal and parietal bones of the same side ; and, secondly, from a partial and unilateral atrophy which involves deviations from the normal force of the heart in badly nourished children.
SCAPHOCEPIIALIA AND PLAGIOCEPHALIA.
These terms represent vicious deformations which destroy the symmetry of the cranial cavity. By scaphocephalia is to be understood a change from the natural shape of the skull in which the parietal bones are united at the sagittal suture, so that the lateral enlargement of the brain is prevented, while that in the direction of the occipital and frontal bones is exaggerated. The parietal bones themselves are considerably increased in length. This distortion has been compared to a boat, and named from the supposed resemblance. So rare is this anomaly, that M. Thamy has affirmed that not above forty examples are known to scientific men. Numerous theories have been suggested in explanation of this anomaly: 1st. It has been advanced that the points of ossification usually existing in the posterior lateral part of the parietal bones are absent, but are replaced by a point situate in the median line, the radiations from which convert the two parietal bones into a single solid bone.
2ndly. Certain speculators refer this state to an antecedent malformation of the encephalon, which consecutively influences the bones, so that the skull moulds and accommodates itself to its contents.
3rdly. Virchow and Huxley contend that this deformity is the result of the obliteration of the sagittal suture, in conse- quence of an inflammatory action taking place during intra- uterine life, which unifies and consolidates the two bones into ?ne, prevents their lateral enlargement, and necessitates an elongation before and behind.
4thly. M. Morselli, adopting this solution in part, holds that its primary cause is to be found in an original vice of the development of the parietal bones, and by the misplacement of the ordinary lateral points of ossification near to the median line, so that the two bones are brought into contact too rapidly, ?r at too early a period.
The theory of Virchow is that which seems to be most generally adopted.
M. Hamy has formulated and reconciled these different opinions thus : that scaphocephalia is due to a premature and intra-uterine synostosis of the parietal bones having an inflam- matory origin, and that the nervous centres do not appear to exercise an influence upon this pathological change.
PLAGIOCEPHALIA
Consists in an oblique or oval deformity of the cranium, in which the greatest diameter, instead of being longitudinal and antero-posterior, is oblique and diagonal; and further, that one of the oblique diameters is greater than the other?in other terms, there is a projection of the frontal bone upon one side, and of the occipital bone upon the other.
According to MM. Topinard and Broca, the anomaly may be traced either to mechanical, pathological, or posthumous causes. In the first place, under the mechanical may be classed the artificial modifications detected in the skulls from meridional America?decrepitude due to the injudicious position given to infants by nurses, especially in ill nourished and atrophic subjects.
[It is marvellous that the effects of the rash employment of forceps in parturition has not been added to this list.? In the second place, among the pathological may be classed the premature obliteration of one-half of the coronal or lambdoidal sutures, which may be associated with other ob- literations ; chronic torticollis, which, whether in the child or the adult, seems to interfere with the nutrition of the face and cerebral tissues; rachitic malformations; the absence of the third convolution of the left cerebral hemisphere in the deaf and dumb, of which M. Broca has seen two examples, or, rather, supposed examples, is conjectured as sufficient to produce this cranial anomaly.
Thirdly. Posthumous alteration in the form of the skull must be traced to the humidity or weight of the soil in which a corpse has been interred. This change cannot be confounded with the effects of rachitis, provided the inferior maxillary bone remains, which is invariably adapted to the glenoid cavity when the deformity has preceded inhumation.
M. Topinard has announced the frequency of plagiocephalia in a series of 525 skulls in the collection of M. Esquirol. The want of symmetry in the cerebral and cerebellar cavities is more frequent and more marked in these than in any series of ordinary skulls. As the skulls under observation were generally those of insane persons, it may be concluded that the modifications which they present are more or less connected with the progress of mental disease.*
1070 r^r;l,n,sJa’:^ and abridged from the Annalcs Medico-Psychologiques, July > n e Bulletins of the Society Anthropologic, 1874, 1875, and 1876.
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