Cerebral Pathology Based Upon the Examination of 411 Cases. Specific Gravity of the Brain in Cases of Insanity
- Author:
Dayid Skaej M.D.,
Physician to the Royal Edinburgh Asylum for the Insane, £(e., 4fc. We are glad of an opportunity of transferring to our pages the fol- lowing valuable communication of Dr Skae, published in the Annual Report of the Royal Edinburgh Asylum for 1851. It refers to a subject of deep and increasing interest. We regret that want of space compels us to omit the tables illustrative of Dr Skae’s experiments in con- nexion with the comparative weights of the brain in the various forms of mental disease, as well as other tabular matter, showing the specific gravity of the grey aud white substance of the brain in the sane and the insane. We, however, give all the results at which he has arrived in relation to both branches of inquiry.
Post-mortem examinations were permitted in 41 cases. They were made with much care, and the following are the results :— Of those examined, 3 had been cases of acute mania, 15 of dementia, 5 of dementia with epilepsy, 3 of melancholia, 9 of monomania, and G of general paralysis.
Calvarium teas of unusual thickness in G cases; 1 of acute dementia, 1 of dementia, 3 of dementia with epilepsy,”and 1 of melancholia. Calvarium teas thinner than usual in 9 cases; 2 of melancholia, 1 of dementia, 4 of monomania, and 2 of general paralysis.
Diploe was absent in 2 cases of monomania. Abnormal adhesion of dura mater to calvarium existed in 4 cases; 1 of dementia with epilepsy, 2 of monomania, and 1 of general paralysis. Pus in the cranial sinuses was found in 2 eases; 1 of dementia with epilepsy, and 1 of acute dementia; in the latter case, pus was also found in the internal ear, and sero-purulent effusion beneath the arachnoid, and in the lateral ventricles.
Increased thickness of dura mater was found in 3 eases ; 1 of acute mania, 1 of acute dementia, and 1 of dementia with epilepsy. Thinness of dura mater was noticed in five cases; 2 of dementia, and 3 of monomania.
Ossific deposit infalx cerebri existed in 1 case of monomania. Abnormal adhesion of arachnoid to dura mater was found in 4 cases ; 1 of acute dementia, 1 of dementia with epilepsy, 1 of monomania, and 1 of general paralysis. Serous effusion into sac of arachnoid existed in 22 cases; 1 of acute dementia, S of dementia, 2 oi’ dementia with epilepsy, 5 of monomania, and G of general paralysis. Extravasation of blood into sac of arachnoid was found in 2 cases of general paralysis. Organised lymph in sac of arachnoid was found in 1 case of general paralysis. Opacity and thickening of arachnoid was found in 2G eases; 1 of acute manih, 2 of acute dementia, 7 of dementia, G of dementia with epilepsy, 2 of melancholia, 4 of monomania, and 4 of general paralysis. Granular deposit in arachnoid over general surface was noticed in 2 cases of general paralysis. Congestion of membranes was noticed in 12 eases; 1 of acute mania, 3 of dementia, 1 of acute dementia, 2 of dementia with epilepsy, 1 of monomania, and 4 of general paralysis. Sub-arachnoid serous effusion was found in 22 cases; 1 of acute mania, 1 of acute dementia, G of (Icmcntia, 2 of dementia with epilepsy, G of monomania, and G of general paralysis. Sub-arachnoid sero-sanguinolent effusion occurrcd in 1 case of dementia with epilepsy. Adhesion of membranes to cortical substance was found in 3 cases of general paralysis. . CEREBRAL FUNCTIONS. 575 Paleness of the grey matter was noticed in 17 cases; 2 of melancholia, C of dementia, 1 of acutc dementia, G of monomania, and 2 of general paralysis. Grey matter was of a dark tint in 3 cases; 1 of dementia with epilepsy, 1 of dementia, and 1 of mclancliolia.
Grey matter had a violaceous tinge in 5 eases; 1 of acute mania, 1 of dementia with epilepsy, 1 of monomania, and 2 of general paralysis. Grey matter had a yellow tint in 2 cases; 1 of acute mania, and 1 of general paralysis.
Grey matter teas softened in 2 cases; 1 of dementia, and 1 of general paralysis.
Grey matter presented limited yellow softening in 3 cases; 2 of dementia with epilepsy, and 1 of general paralysis. While matter teas softened in 2 cases: 1 of dementia, and 1 of general paralysis.
Punctos vasculoscc were very numerous in 15 cases ; 1 of acute dementia, 2 of dementia, 5 of dementia with epilepsy, 1 of melancholia, 2 of monomania, and 4 of general paralysis.
Apoplectic effusion was found in 1 case of monomania. Serous effusion into lateral ventricles was found in 1G cases; 2 of acutc mania, 1 of melancholia, 5 of dementia, 2 of dementia with epilepsy, 2 of monomania, and 4 of general paralysis.
Scro-sanguinolcnl effusion into lateral ventricles occurred in 1 case of acute dementia.
Granular deposit in membrane of lateral ventricles was found in 3 cases; 1 of dementia with epilepsy, and 2 of general paralysis.
Cystic bodies in choroid plexuses occurred in 9 cases; 1 of acutc mania, 1 of dementia with epilepsy, 4 of monomania, and 3 of general paralysis.
Pineal body was unusually large in 4 cases of dementia.
Veins of Galen were much dilated and clogged with decolorized clots in 1 case of dementia with epilepsy.
The brain was carefully weighed in every case, and the weights, with those of other viscera, together with the specific gravity of the grey and white matter of the brain arc recorded.
The general conclusions to be derived from the preceding abstract are, that, in a large proportion of the deaths, well-marked appearances were found indicat- ing increased vascular action, or slow inflammatory processes affecting the membranes of the brain, and producing thickening and serous effusions. These appearances were most constant and most distinct in the deaths from general paralysis, where there was also found a peculiar kind of softening of the grey substance of the brain, and on examining this part of the brain under the microscope, the cells of which it is principally composed appeared to be en- larged and altered in form. In these eases, adhesion of the membranes to the surface of the convolutions was present in all instances where there was not such a quantity of serous effusion interposed as to prevent it; in stripping off the membranes, small layers of grev matter were stripped off’ with them, par- ticularly on the lateral surfaces of the hemispheres.
With the exception of the morbid changes last mentioned, which are limited o cases o general paralysis, all the other morbid appearances are found very ficqucnthm the brains oi persons who have died of other diseases, and without anj mental affection. And, on the other hand, eases arc not unfrequently to be met with in the dead-liousc of the Asylum, of patients who had exhibited, during lite- lor many months or even years—all the symptoms of raving mad- ness, and m whose brains the morbid appearances described are altogether wautmg, and m which the brain could not be distinguished from that of one who had died in all the vigour of a sound mind.
From these facts it must be inferred that the morbid appearances described, although the very frequent concomitants of insanity, do not constitute the pathological conditions by which the symptoms of mental derangement are Sroduccd; and that we arc, in fact, ignorant of the true pathology of this isease.
There are many considerations which may well lead us to doubt whether any other morbid changes in the structure of the brain may ever be discoverable in insanity. The analogy of the symptoms to those produced by poisons which are known to enter the blood, the suddenness of the invasion in some cases, and the suddenness of the cure in others, even occasionally of long standing, the remarkable remissions, and at times the temporary restoration for a few hours or moments, to perfect sanity in persons long plunged in profound dementia, or labouring under a chronic and protracted mania, arc facts which lead to the reflection that insanity may be a disease of the blood, or may depend upon a peculiar orgasm of the nervous centres,—upon conditions not to be discovered in the brain after death.
Pathological investigations, however, for changes in the nervous substance itself, are not to be abandoned until wc have exhausted all our means of obser- vation ; and it occurred to mc, accordingly, some years ago, to commence a series of experiments by collccting the weights of the brain, cerebrum and cere- bellum,—by measuring the breadths of tlic grey matter,—by endeavouring to determine the degree of hardness or softness of the ccrcbral substance, by ascer- taining by what length of a column of water it could be broken up,—and, more lately, by taking the specific gravity of the grey and white substance of different parts of the brain.
In an hospital for the insane, where the deaths are much fewer than in a large general hospital, it takes some years before a sufficient number of data can be accumulated to warrant any general inferences; and I feel that the data which I possess, although the accumulation of some years, arc still rather meagre. I am induced, however, to record them, as offering a few very inte- resting suggestions, which may lead others to follow similar methods of obser- vation, and thus facilitate the collection of a larger number of facts. My measurements of the grey matter, and experiments on the hardness and softness of the ccrcbral substance, I do not propose to detail at present, as I have 110 similar observations on the brains of persons dying sane with which to compare them. I shall contine myself, therefore, to the weight and specific gravity of the brain, and to such general deductions only from those observa- tions as the number of facts seem to warrant. I shall leave for another opportunity several comparisons and inquiries which might be instituted through these methods, inasmuch as the data sccni to me too few to justify speculations which relate to more spccial questions.
I have compared my observations on the weights of the brain with those collected in the Royal Infirmary of Edinburgh by the late Dr John Reid and Dr Peacock, and the experiments on its specific gravity with those published by Dr Sankcy in the “British and Foreign Mcclico-Chirurgical Review,” for January, 1S53 (vol. xi., p. 210), and made in the Royal London Fever Hospital. The weights used were avoirdupois.
The observations made of the weights of the brain comprise 109 cases, of which 98 were males and 101 females. The tables exhibit the weights of the heaviest and lightest cnccphalon, ccrcbrum, and cerebellum (with the pons and medulla), and their average weights at different periods of life. The figures arc arranged in parallel columns with those of the corresponding results from the tables of Drs. Kcid and Peacock.
On comparing the columns showing the heaviest brains in the sane and insane males,it will be seen that in only one instance did the cnccphalon exceed CO ounces in the insane, while in several of the sane it amounted to 02 ounccs and up- wards, the heaviest brain in the one series being GO oz. 8 dr., and the heaviest in the other being G2 oz. 12 dr. It will also be seen that, with two excep- tions, the superiority in weight was among the brains of the sane in each of the quinquennial or decennial periods into which they are classified. Whether tins justilics the inference that persons having large brains are less frequently the subject of mental derangement than others, I shall not venture to say; but the fact is a striking one when contrasted with the results derived from a com- parison of the average weight ot the entire number of cases, ‘where it appears that the average weight is increased in persons dying insane. The average weight in the insane from fifteen to ninety years ol age being 50 oz. 2 dr., and in the sane 49 oz. 14 dr.
Different results arc derived from a comparison of the weights of the brains of the females; here, in one exceptional case, the brain weighed 61^ ounces in a female who died insane, but in a majority of eases the greatest weight was on the side of the sane. On taking the average of all the cases, the weight of the brain in the insane was 44 oz. only, anu in the sane 44 oz. 5 dr.
The comparison, however, establishes, I think, a strong presumption that the absolute weight of the brain is increased in the insane, when we reflect that in many cases of insanity, the absolute size of the brain must be materially dimi- nished by the large quantity of serous effusion found in the ventricles, arach- noid sac, and sub-arachnoid tissue.
This increase in weight, however, appears to depend chiefly upon an increase in the weight of the cerebellum ; for, oil comparing the weight of the ccrebra in the two series of cases, it will be found that the difference is inconsiderable, and indeed in the ease of the females that it is in favour of the sane. On comparing, however, the columns showing the weight of the cerebcllum (with the pons and medulla) in the two classes, it will be found that there is almost a uniform preponderance in the weights of those of the insane. The average weight in all the eases of the insane males excceds that of the sane by 4 drachms, and in the females by 5 draclnns.
In a Table the ratio between the cerebellum (with the pons and me- dulla) and the cerebrum is given at the different ages distinguished. Here the same fact is very clcarly brought out; in almost every instance the cerebellum in the insane being heavier in relation to the cerebrum than it is in the sane. From the average of the entire number, the cerebellum was found in the males to be as 1 to 6*748 in the insane, and as 1 to 7’0G in the sane ; and in the females as 1 to 6”64 in the insane, and only 1 to 7 in the sane. The cerebcllum therefore is considerably heavier in relation to the cerebrum in the insane.
This mode of estimating the results appears to me to be free from the source of fallacy arising from the small number of eases compared; when we compare the absolute weights together, as here, on examining all the cases separately wc lind, in almost every instance, the cerebcllum of each brain heavier in rela- tion to its own cerebrum in the insane than in the sane.
but U1 :ult^ a number °f data, may modify these results; highly nrobahWi l +T0 ^ } e thus collected, it may be regarded as sons dymg insane & C18 u” 1ncrea*e i* the weight of the cerebellum in per’ monomania’ ^o^li^dr^^J °f cnccl)lialon in males was 53 oz. 13} dr.; in 4G oz 61-2 dr • tliowo- ;» n dementia, 49 oz. 11JL dr.; and in general paralysis lvsis rfmmrL ^ grC.at cst in lcast il1 Seneral Pa™” samc series while thov’^i aVfraSe, weights of the ccrcbclla, &c., however, in the SXTffiSaSZ ■ Tiito folw thc san,c decrease from mania> the 12 dr G oz II 0 dr 3? ^mentis, the weights being respectively 6 oz. U dr., 0 oz. 11TV dr., and 6 oz. 9^ dr.; thc cases of general paralysis present the highest average, the average weight being G oz. 13^ dr. From the fact that in general paralysis the morbid appearances arc most constant and most distinctly marked, this result might perhaps be anticipated, if we assume what I have endeavoured to show, that the relative weight of the ccrcbcllum to the cerebrum is increased by insanity, and that the ccrcbcllnm is the organ prin- cipally affected. This increase, too, would appear from a review of the history of the ease to bear a constant relation to the form of the disease, and to be greatest in more protracted and gravest eases. On comparing the average weight of the cerebellum to that of the cerebrum in the cases classified as above, it was found in males to be as 1 to G*9735, G*7549, G*5G25, and G*2511, in mania, monomania, dementia, and general paralysis respectively. Excepting mania, the same gradual increase in the relative weight of the cerebellum was found to obtain in the females, the cerebellum being to the cerebrum in them as 1 to G*5338, G*412, G*5943, and G’0135 in same class of cases respectively.
It appears, therefore, that in cases of comparatively short duration, there is the smallest amount of increase in the relative weight of the ccrcbcllum, and that in general paralysis the greatest increase takes place.
In reflecting upon these results, the impaired control over the voluntary movements, which forms so marked a feature of general paralysis, and the very constant increase of the relative weight of the cerebellum in this dis- ease, must at once be viewed as very interesting and important facts in con- nexion with the functions ascribcd to the ccrcbcllum by Fleurcns and other physiologists.
May it not be asked—supposing it to be established by an extended scries of observations, that there is uniformly an increase in the relative weight (and specific gravity, as we shall presently sec,) of the cerebellum as compared with the cerebrum in all forms of insanity—whether it may not be inferred that the ccrcbcllum is the organ through which we cxcrcisc self-control,—control over the volitions and successions of our thoughts, as well as over the voluntary muscular movements;—a perturbed volition or a loss of self-control, being of all other symptoms the most essential characteristic and pathognomonic feature of insanity ?
The specific gravity of the grey and while substance of the brain was taken in SO eases, of which 39 were males and II females.
The specific gravity in the eases of insanity was almost uniformly higher, and this observation applies to both the grey and white matter. In Dr Sankcy’s cases, the lowest spccilic gravity of the grey matter was 102S, in the Asylum ones the lowest was 1030; the highest in Dr Sankcy’s cases was 101G, in mine 1019; while the average specific gravity in all the cases of both sexes was in the former 1034, and m the latter 1038, showing an increase in the specific gravity in the eases of insanity.
I he lowest specific gravity of the medullary substance in the healt hy brains was 1032, in the diseased 1032 ; the highest in the healthy was 1018, in the diseased 1053 ; the mean of all the cases was 1*0411 in the sane, and 1*0429 in the insane, showing an increase in the specific gravity of the white matter of the brain in eases of insanity.
These results arc corroborative of those obtained by Dr Sankcy in his observations at the London Fever Hospital, where in all the cases complicated with cerebral symptoms of a grave charactcr preceding death, such as convul- sions, strabismus, paralysis, and utter unconsciousncss, the specific gravity was high, averaging both in thcy/vy and white matter 1011. He makes two exception in regard to the white matter, in both of which the specific gravity was below the mean; these were both cases of children of eight and ten years of age, aim both of tubercular meningitis. Deducting these cases, the average specilie gravity of tlie -vlritc matter in his series of cases, complicated with cerebral symptoms, was 1043.
On examining my cases in detail, I find that in most of those cases where the specific gravity of the grey matter was considerably below the mean, the patients had died of phthisis, and in other instances of exhaustion occurring at an advanced age. Where exceptions to this general inference wen met with, it was found that cither the symptoms immediately preceding death were of a grave character, or that the morbid appearance found in the membrane indicated chronic inflammatory action.
I have also taken the specific gravity of the grey and white matter of the cerebellum in forty-three cases. I have placed on the table the averages at different ages. The number of observations is too few to warrant more than a presumption that the specific gravity of the cerebellum is higher than that of the cerebrum. The difference is much more apparent when, instead of coin- paring averages, the specific gravity of the cerebellum is compared with that of the cerebrum to winch it belonged.
I have not been able as yet to obtain a sufficient number of data showing the specific gravity of the cerebellum in the sane to furnish comparisons with the ob servations 1 have made. Dr Sankey has kindly furnished me with a number of observations made by him; but as he has not separated the grey from the white matter, but has taken his specific gravity from a portion of brain containing both, 1 cannot compare my observations with his directly. I may state, however, that tlicy tend to the same general conclusion, that the specific gravity of the cerebellum is higher than that of the cerebrum, and that it is so in healthy brains as well as in diseased ones, although probably in a smaller ratio.
Through the kindness of Dr Haldane, I have been enabled to make a few observations on the specific gravity of the grey and white matter of the cere- bellum in persons dying in the ltoyal Infirmary. The number of cases suitable for a comparison of this kind of cases dying without any cerebral symptoms, has as yet been rather too small to merit a special record. I may, however, state that in a scries of five cases of males dying without cerebral symptoms, the average specific gravity of the grey substances of the ccrebellum was 10i2, that of the cerebrum being 1011. In the eases of the insane examined by me, the average was 1040 for the ccrcbelluni, and 1035 only for the cerebrum, showing a much greater increase in the ratio in the insane than in the sane, although the absolute specific gravity was less in these particular cases. The white substance of the cerebellum in the five cases referred to, had an average specific gravity of 1-0143, while that of the cerebrum was 10430. In the cases examined in the Asylum, the average specific gravity of the white substance of the cerebellum was 1014, while that of the white substancc of the cerebrum in the same cases was T039 only—thus showing a small increase in the absolute specific gravity of the white substance of the cerebellum in the uisane in the eases compared, and a very considerable increase in the relative specific gravity to that of the cerebrum in the case of the insane. cernhoi11 ^9se. data, although limited, I infer that the specific gravity of the that of iiio nS n!crcuscd m insanity, and attains a greater increase in relation to In comLw d°Cs.iu Prsons W *™c
and taking the averaSJTfnlfif?Vlty m UlC lli””crcut forms of mental disease, gravity of the otpvnK 7 lC ca?cs of cach kind» 1 find thc lowcst sl)ccific still 0 003 above tho * oc.cur lu cases of dementia, where, however, it is occurs in®caSrf Sd«S3M ^ ^ ?C specific gravity next in mania, and the tllC “CXt m ^ P^alysis, thc Of the white substance, the lowest average of specific gravity occurrcd in cases of mania, 1010; the next in dementia, 1011 ; the next highest in general paralysis, the next in monomania, 1011; and the highest also in epi- lepsy, being 1*0158.
The results of the preceding observations arc curious and interesting. They are inferences certainly from a comparatively limited number of data; out they arc, I think, sufficient to prove that more extended observations of a similar kind may probably lead to some satisfactory and important deductions regarding the pathology of insanity and the functions of the brain.
In conclusion, I think it right to state, that the specific gravity of the central substance was taken exactly in the same manner as that followed by Dr Sankey. A number of jars were prepared with solutions of common salt, the density of which was determined by the urinomctcr. A scries was prepared, ranging from 1*030 up to 1*050. Small portions of ccrebral matter were dropped into these solutions, until a jar was found in which the portion so dropped floated midway, at the point of which it sank. This fluid gave the specific gravity, and to insure accuracy, and avoid fallacies arising from the spontaneous evaporation of the fluid, the specific of the fluid was in every ex- periment tested afresh by the urinometer at the time of the observation. The temperature of the room was G0° E. It is right to repeat the precaution pointed out by Dr Sankey, namely, to take the first effect of the experiment, and that only; as by allowing the portion of brain to remain a few minutes oidy in the solution, its specific gravity rapidly alters by endosmose, and it will soon sink even in the strongest solutions. From not attending to this {>rccaution, it is, I presume, to be explained why, in the pathological report atcly published of a Metropolitan Asylum, the brain is stated in many cases to have had a specific gravity of 1 090 and upwards !
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