Article 3
- Author:
Noel H. M. Burke, M.R.C.S., L.R.C.P., D.P.M.
(Senior Assistant Medical Officer, The Fountain Mental Hospital) There is room for much controversy over the causation and mechanism of some of the mental diseases, and one can take sides with the believers in psychogenesis or with the exponents of toxic absorption from teeth or intestines. There can be little doubt, on the other hand, that Mental Deficiency depends essentially on a limited functional capacity of the brain structures. This may be due to the lack of some controlling chemical substance, as in cretinism, or to injury to cells which were previously healthy and normal in structure, as in meningitis, encephalitis, or cases of long and difficult labour. These are examples of secondary Amentia, and constitute, on present evidence, some 2o% of all aments. The condition might more logically be called by some such name as infantile dementia, to stress the fact that it is a brain that was inherently normal which is now at fault.
The remainder of defectives are primary aments, and their weakness is due to structural deficiency in the brain cortex. For all types of deficiency, therefore, it may be laid down that the condition is purely and definitely a bodily one in its mechanism and genesis, and that the essential seat of disorder is in the brain cortex.
Much work has been done on this nuclear subject in the pathogenesis of Mental Deficiency, and its result may be compressed into a statement that gross or minute abnormality of structure can be found in the brain of every defective.
With regard to the secondary group of aments, the pathology of each case is fairly obvious when the particular cause is remembered. In the primary group there is more or less massive structural anomaly} involving whole con- volutions, lobes or even hemispheres, in a few idiots and particularly in the Microcephalics.
The majority of defectives, however, show anomaly on a finer scale, so that the brain is small and light and of simple convolutional pattern, while microscopical examination shows that the cortical cells are poor in number, poor in structure and often disorderly in arrangement. In either case, the essential nature of the anomaly is imperfection, imperfection of progress and development, so that at no date have the brain elements reached their normal stage of structural adequacy. This contitutes the one fundamental condition in the pathology of all primary mental deficiency, the true Amentia, but a similar imperfection may be perceived in many cases to involve structures and organs other than the brain. It is not unprofitable to study this wider physical aspect of Mental Deficiency, for to do so, while interesting in itself, may just possibly throw some more general light on the subject of mental deficiency as a whole and on its causation in particular.
In general structure, whether measured by height or girth or weight, the average defective is inferior to the average member of his race. The lowest actual measures and the lowest average in a large series were each achieved by the mentally defective. In this respect, to arrive in the midst of a colony of defectives gives the same impression as to arrive at the Gare du Nord in Paris, where the inhabitants appear to be so much smaller than the people one has left behind either in England or at Calais. To put this point in another way, it may be said that the defective child who comes for examination is probably two years older than he looks.
But other visual impressions are produced on confronting a group of defectives: the facial expression, the gait and gestures and the general bearing catch the eye. These often show quite distinctive characteristics, but it is not so easy to explain all of them on grounds of imperfect anatomical structure. They are so much functions of habit, and particularly of habitual attitudes of mind, that they should be regarded more as the reflections of such imper- fection than as the direct signs of the imperfection itself.
If we now examine the defective patients more minutely and take detail by detail, we find a number of matters of interest which were fully described, from another point of view, in the Proceedings of the Royal Society of Medicine for February, 1931.
In the records of a series of 2,476 low grade defectives under the age of 16 years, some 200 abnormalities of structure were mentioned, as shown in the following table: ? TABLE A?” Stigmata ” Recorded in Series A Total Eye conditions 15 cataract, 14 deformities, etc. (2 coloboma, 2 glaucoma), 30 blind 59 Ear conditions asymmetry 34, ” deformed ” 5, accessory auricle 1 40 Face conditions asymmetry 7, ” foetal ” 1, hypertelorism 2, deformed nose 1 11 Head asymmetry 5 5 Hare-lip 2 Cleft Palate partial 4, degree not specified 7 11 Teeth double row 2, absent incisor 1, other ir- regularities unlisted 3 Accessory nipple … 1 right, 1 left 2 Heart conditions … patent foramen ovale 3, congenital heart 21 24 Hermaphroditism … hypospadias 1 … 1 Congenitally short leg … right 1 1 Precocity (? pituitary)… 2 2 Nsevus 2 (nsevoid amentia) 2 Ichthyosis 3 3 Spina bifida with hydrocephaly 2, with paralysis 1, others 2 5 Meningocele 3 3 Hand conditions … web 1-2 fingers, 2-3 fingers (2 cases), not speci- fied 3, 6th finger or extra thumb 2, 4 fingers too large 1, congenitally con- tracted fingers 1 10 Foot conditions … web 2-3 toes (4), 3-4 toes (2), 4-5 toes (2), un- specified 4, ” deformed toes ” 2, deformed foot 1, small toes 1, 3 toes incomplete 1 17 The corresponding list for another series of 583 cases, who were especially examined in the search for such conditions, follows: ? TABLE B?” Stigmata ” Recorded in Series B Total Eye conditions congenital cataract 2, blind 4, optic atrophy 1 7 Ear conditions asymmetry 5, deformed 1, accessory auricle 2 8 Face conditions asymmetry 6, deformed 1, hypertelorism, with or without epicanthus 31. Epicanthus 10 48 Head asymmetry 1 1 Hare-lip 1 1 Palate partial cleft 3 3 Accessory nipple … 2 right, 2 left 4 Heart ” congenital heart “2 2 Hermaphroditism … 1 1 Nsevus naevoid amentia 2 2 Albino 1 1 Hand conditions … webbed fingers 2, deformed thumb 2, index 1, deformed hands 1, 6th finger 1, small finger 1, synostosis of metacarpals 1 … 8 l’oot conditions webbed toes 5, long or short toes 15, deformed foot 1, 6th toe 1 22
In a number of these conditions there is evidence of imperfection of structural development localised to the respective organs or parts. Coloboma, ?r instance, is the persistence of a cleft formed during the development of e eye, which should be closed by a process that is normally completed by the th week of intra-uterine life. Similar processes unite the two sides of the growing palate and of the growing lip at the same age. Failure of union etween the sides of the back occurs much later in the case of spina bifida, where the bony arch of the spinal canal should be formed during the 3rd month, and of meningocele where the gap between portions of the occipital bones should close at about the time of birth.
In the heart, again, the foramen ovale gives a normal communication between the right and left auricles during pre-natal life, but should be occluded as a result of the new conditions established at birth, when respira- tion by the lungs replaces aeration of the foetal blood by the placenta. Closure of this foramen may be delayed or incomplete, but this failure is thought to be unduly common in Mongolian defectives.
In a somewhat similar category is delay in the onset of puberty which is noted in many cases of amentia, menstruation not appearing until 14, 15 or even 17 years in a large proportion of the female patients. This physiological delay depends on an imperfection of the underlying structure of the endocrine glands. It is not so easy to give an accurate date to the appearance of puberty in the male, but the following points are of great interest and of considerable significance.
In the records of 128 consecutive cases of defective boys under 16 of whom the facts were precisely stated, both testicles were undescended in 63 and one testicle was undescended in each of a further two. In this series every age was represented from 4 to 15, and instances of this imperfection appeared at each age. The distribution, however, was not a chance scattering but was related to the age in such a way that 66.6% of those from 4 to 8 years old showed this mark of imperfection, while it was found in only 25% of the remaining cases in the older group. The general inference from these figures is that undescent of the testicle is present in two-thirds of all male defectives when born, that late descent occurs in some, but that the process is never completed in a quarter of the total.
Now it is not justifiable to propound a general rule on a series of 128 cases, but the. figures are large enough and definite enough to suggest very serious consideration. If these findings be confirmed by further observations the gates are opened on certain paths of thought. The testicles should be fully descended at birth, if not a month earlier. Up to about the 7th year of life non-descent may be regarded as being merely delayed, but after that age its absence from the scrotum must be regarded (according to Mr. E. H. Corner in the Practitioner’s Surgery) as permanent.
Whether delayed or permanent in non-descent, such a testicle is found to be imperfect in structure and in capacity, and it is unlikely to reach an adequate maturity. The imperfectly descended testicle may have an internal secretion, but it is rarely spermatogenic, and then only for 3 or 4 years from about 20 to 23.
Is this set of facts to be regarded, from the aspect of causation, as evidence of a general failing of biological quality in mental defectives and as a natural method of automatic extinction of an inferior strain ? And, from the point of view of social treatment, do these facts demand consideration in discussion of the problem of legalised sterilisation?
The group of conditions so far considered appears to be a homo-geneous one and to carry on the simple idea of imperfection in localised sites. Yet it is not at all so simple, for there is much reason to assign to spina bifida and to hare-lip causes other than inherent developmental imperfection. Spina bifida can be produced experimentally, in suitable species, by treatment of the developing embryo, and its non-artificial production has been ascribed to the effect of morbid conditions of intra-uterine environment rather than to con- ditions inherent in the developing cells. If such an explanation be true, and if it be true in every case, then cleft palate and similar conditions cannot be regarded as evidences of such impaired biological quality as is assumed in the primary amentias.
In so far, however, as there is a tendency for such things to be familial there must be some familial cause, and possibly it is to be found in an inherit- able quality affecting the physiology of gestation.
This is at present no more than pure speculation; too many of the factors are unknown, but such speculations may act as sign-posts in the search for knowledge.
It must be borne in mind, however, that the evidence of the present investigation, and of previous observations, shows little correlation between the incidence of mental deficiency and of hare-lip and cleft palate, so rules that apply to the two latter do not necessarily hold for the former. In the case of undescended testicle the correlation appears to be quite a definite one, as has been shown above, and tentative inferences are justified.
Another type of anomaly which appears to have a definite, though less Marked, proportional incidence, is syndactyly or webbing of fingers or toes. As this condition is normal at the 7th week of intra-uterine life its persistence may be explained as an arrest of development, but we are now led towards another class of anomalies which appears to be characterised by aberrance or distortion of development rather than by simple imperfection. It is difficult to draw a complete division between syndactyly and polydactyly, or to ex- clude from the group the cases of undue largeness or smallness of individual digits, and other similar anomalies, for there is a tendency for these to occur together. It has been suggested that there is some controlling factor in develop- ment which governs ordered growth in the extremities. This view has been put forward by several observers who approached the matter from the stand- points of different kinds of observation.
Before attaching too much importance to developmental physical anom- alies, whether of aberrance or of imperfection, as evidence on the nature of Cental deficiency, it is necessary to return to the question of the degree of correlation between the two, and this is remarkably difficult. In the larger of series referred to only 8.2% showed these anomalies, while the smaller and more carefully examined group showed 19.5%. There appear to be no observations on normal children that are quite commensurate, but scattered gures are to be found for various individual conditions. These are shown 0ri a percentage basis in the following table, the normal figures being from various sources, and quoted by Dr Tredgold or by Sir Arthur Keith. The Egyptian and African figures, interesting for comparison, are quoted in a paper by Dr Hugh Stannus.
TABLE C. Normal Egypt & Africa Series A Series B Abnormal ears 34-44 ? 1.61 1.37 Auricular fistula 0.6 4.6 ? ? Auricular appendage … 0.66 ? 0.04 0.34 Hare Lip ? 0.15 0.04 0.08 0.17 Cleft Palate 0.062 ? 0.083 0.68 Polydactyly ? 0.016 0.05 ? 0.34
The entries in the ” normal ” column are a small reward for a fairly wide search through the literature, and study of the table shows how little real information is still available and how impossible it is to argue from these meagre data.
The only general conclusion that seems to be justified is that there is little support for the common idea that there is a close relationship between so-called Stigmata of Degeneration and Mental Deficiency as a whole.
There is no doubt that an examination made for the purpose of finding these things is more productive than a simple routine examination, and the ” B ” Series may be taken therefore as giving the true maximum figure at a little under 20%. 7’his is probably a higher ratio than is to be found in the average population but certainty is at present lacking, and any inferences based on the theories of a relationship between mental deficiency and this sort of localised physical deficiency must be made with full reserve.
The theory has been used very largely as an aid to diagnosis between primary and secondary deficiency, and between deficiency and other conditions that give an impaired mental performance difficult to distinguish from true mental defect. This method is probably justifiable, but it should be relied on only to a very limited extent, and should be given weight only as yielding supplementary and not conclusive evidence. It has been suggested by some that one ” stigma ” means little, but that two or more in one individual have definite evidential value. When groups A and B (3,059 cases) were searched for information on this point, there were found 20 cases with 2 anomalies each, including epicanthus as one anomaly, 3 with 3 and 1 with 4.
The grouping of ” stigmata ” seems, therefore, to occur too seldom to be of much value in a negative sense, that is to say, absence of ” stigmata ” proves nothing. Even the presence of grouped anomalies proves little, for it has no relation to degree of defect, and this confirms the general evidence of the statis- tics from Group A.
TABLE D?Stigmata Related to Degree of Mental Defect No. of cases Stigmata Percentage Idiots 1,067 … 85 … 7.0 Imbeciles 1,397 … 118 … 8.4 Feeble-minded 12 … 0 … 0.0 All cases 2,476 … 203 … 8.2
It was thought that physical anomalies, if related to mental deficiency, should be found with increasing frequency as the degree of deficiency increased, yet this proves to be untrue. Group A contained over 1,000 idiots and more im- beciles, and the relationship to each group is simply that to deficiency as a whole.
When an examination was made into the incidence of physical anomalies among the different types of deficiency, a different picture was obtained.
TABLE E?Stigmata Related to Type of Mental Defect No. of cases Stigmata Percentage Simple 942 … 76 … 8.0 Paralysed 546 … 46 … 8.4 Hydrocephalic 70 … 7 … 10.0 Epileptic 542 … 34 … 6.2 Syphilitic 53 … 0 … 0.0 Cretin 33 … 3 … 9.0 Microcephalic 90 … 6 … 6.6 Mongol 200 … 31 … 15.5 All types 2,476 … 203 … 8.2
The one outstanding feature is provided by the Mongolian group with nearly twice as many anomalies as the average for all defectives, and that figure is obtained after excluding those conditions, such as epicanthus and small simple ears, which are part of the condition of Mongolism.
This seems to provide evidence that those are right who are driven by contact with aments to the belief that Mongolism is a distinctive condition, different in nature and causation from the other types of mental deficiency. Perhaps there is here also a clue to the problem of such nature and causation, a problem that many workers would be glad to solve.
SUMMARY !? The essential physical basis of mental deficiency is imperfection of brain structure. -? Other structural abnormalities are seen in many defectives, both generalised and localised, which may be grouped under the heads of imperfections and aberrations of growth. 3- The possible values of these conditions are discussed as evidences of the nature of mental deficiency. 4- Normal standards are inadequately known and only tentative conclusions are justified. 5- There is a correlation of localised physical anomalies with mental defici- ency amounting to about 20%. 6- There is no relation with degree of defect but there is a definite relation with one type of defect, namely, Mongolism. I have to thank the Medical Superintendent, Dr James Nicol, for per- mission to use the records of his hospital in the compilation of the statistics, and to state that the London County Council is in no way responsible for any ?f the views expressed.
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