were located in the right hemisphere of the cerebrum of a man; they were of the size of a hen's egg, and penetrated into the ventricles. Melanotic deposits were also found in other organs of the same subject, and the veins passing from the tumors in the brain, were observed to contain melanotic matter in a fluid condition. Dr. Hooper's work on the brain also contains a plate representing this disease; and, recently, Dr. Clendining brought a case of the kind before the notice of the Pathological Society.1 The simple fatty tumor is only found in the choroid plexus, where it does not, however, attain any great size. The fatty growths most frequently met with in the brain are those which are termed cholesteatoma; they are formed of concentric layers, and present a metallic lustre; they consist of membranous layers, ordinary fat-vesicles, and cholesterin plates, and are inclosed in a capsule. They attain the size of a walnut or goose's egg. FIBROID TUMORS. We have searched in vain for the evidence of fibrous tumors occurring in the cerebral tissues, though their existence is admitted by Rokitansky. None of the pathological works that we have consulted record a case of the kind; we are, therefore, inclined to assume that they are limited to the dura mater, and that fibroid tissue only occurs in the metamorphosis of old cysts or envelops of the heterologous growths found in the brain. CYSTS. Cysts of various kinds present themselves in the brain; those resulting from apoplectic effusions are the most common, and present, as we have seen, various stages of development. It is probable that, in many instances, their formation may be due to the same process as that described by Mr. Prescott Hewett, as giving rise to the inter-arachnoid cysts, viz: a formation of a false membrane, subsequent to the effusion from the sanguineous clot. The firmness and thickness of these cysts will serve to distinguish them, even when they only contain serum, from the true hydated cyst. The microscope, by determining the presence of entozoa, or the parallel lamination of the envelop peculiar to hydatid growths, will further assist our diagnosis. The only parasites hitherto discovered in this locality, are the ecchinococcus and the cysticercus cellulosæ, which, however, are not to be viewed as essentially distinct. The acephalocyst occupies the peripheral, more frequently than the central portions of the hemispheres, and is found to present no connection with the surrounding tissues. When met with in the brain, there is generally a coincident development of the same parasites in the liver, a fact first pointed out by Aran, who has analyzed forty-seven cases of this kind. 1 Report of the Pathological Society of London, 1847, p. 15. THE PITUITARY BODY. The pituitary body presents morbid conditions, which, generally, are rather pathological curiosities, than that they offer any peculiar points of general interest; in a physiological point of view, tumors or cysts occurring in it attract attention, from their not producing those symptoms which are generally attributed to pressure upon the encephalon, and this is supposed to be due to the force acting in an upward direction. Thus, they are rarely accompanied by paralysis, though acquiring an extent sufficient to displace the lateral ventricles with the thalami and corpora striata, a circumstance presenting, as Dr. Romberg remarks, an analogy to the different effect produced upon the conduction of a nerve by a tumor, according as the nerve is gradually distended or forcibly compressed. Neither Rokitansky, who treats diseases of the pituitary body in detail, nor Engel, who has written a monograph on the subject, corroborates the observations of Joseph Wenzel, that disease of the pituitary body is an essential feature in epilepsy. The pathologists of our own country have not observed a relation of the kind. Epilepsy is met with as a result of the most various degenerations, or morbid products within the brain, independently of any marked disease of this appendix cerebri; it is not constantly associated with any one lesion, and in the cases of disease of the pituitary gland, given, for instance, by Dr. Bright, we find no epileptic seizures during life; or, conversely, we see epilepsy' occurring without any disorganization of this part. The pituitary body does not seem to bear any definite relation to the manifestations of the mind. Dr. Bright gives an instance in which it was absent; the patient was a man who died at the age of forty-eight, of softening of the left corpus striatum; but he had enjoyed thorough good health until five months previously. In the course of our account of cerebral morbid anatomy, we have had occasion to allude to the occurrence of aneurism of the cerebral arteries; the subject will meet with a fuller consideration when we treat of the diseases of the vascular system; but we could not dismiss the pathology of the brain without pointedly remarking upon their importance in the production of cerebral symptoms, and as a more or less direct cause of death. The diseases of the arteries play a most important part in the production of cerebral disease, and in many of the morbid conditions which we have passed in review they may be viewed as one of the main elements. Reports, &c., case cxlii. An interesting case of disease of the infundibulum and pituitary body is given in the records of the Pathological Society of London for 1849, p. 19. CHAPTER XI. THE SPINAL CORD AND ITS MEMBRANES. WE must commence this section with the ungratifying confession that it is a subject upon which our knowledge is very limited. This is partly owing to the various baseless hypotheses which the pathology of the spinal cord has admitted, and still more to the mechanical difficulty which presents itself to the investigation of its derangements, during life, as well as after death. The depth of muscle which invests the spinal column on the dorsal surface, the tediousness of the procedure of sawing through the arches of the vertebræ, and the routine system of conducting postmortem investigations, militate against the frequent examination of this organ. Nor can we hope that any great amelioration will take place in this respect, until our hospitals and medical schools are able to endow the curatorships of morbid anatomy in such a manner as to secure the undivided services of men of science, for a series of years. So long as the spinal cord was considered only as an aggregation of nerve-fibres, serving to conduct influences to or from the brain, it was natural that its pathological changes should be regarded as of a secondary importance; but since the researches of Dr. Marshall Hall have shown its claim to be considered in the light of a central organ of the nervous system, endowed with powers independent of the brain, the morbid anatomy of the spinal cord has also acquired a higher dignity. As our knowledge of its physiological endowments, and of its structure, is enlarged, and as our means of physical diagnosis are improved, we may hope to see its morbid anatomy better understood and appreciated. At present, we can scarcely be said to have advanced beyond the very threshold of this department of science. We shall follow the same order we adopted in treating of the morbid anatomy of the brain, and examine successively the post-mortem appearances of the dura mater, the arachnoid, and pia mater, and then of the cord itself. In all cadaveric examinations of the spinal column, it is particularly to be borne in mind that the position of the body after death may influence the post-mortem phenomena, independently of morbid action, owing to the gravitation of the fluids to the depending portions, and their secondary effect upon the nerve-tissues. How important it is to attend to this point, is illustrated by some observations, made by Mr. 'Curling,' of tetanic cases. On examining the body of a man who had died of tetanus, which had been placed on its face immediately after death, Mr. Curling found that part of the pia mater covering the anterior columns of the medulla spinalis remarkably vascular; a circum 1 On Tetanus, p. 48. stance which would necessarily induce a conviction in the mind of the pathologist, that an essential lesion had been discovered, by which the exaltation of motor action could be satisfactorily explained. Unfortunately for the conclusive force of the observation, in three other instances, where the bodies were suffered to remain in the usual position, the vessels on the posterior parts only were observed to be turgid. This influence of position is more likely to affect the spinal cord than the brain, owing to its being less excluded from atmospheric agency. It is also important to remember that the relation of the envelops of the cord differs from that existing between the investments of the brain and their contents in various material points. The movements of the osseous case of the cord would have rendered a close adhesion with the membranes a source of frequent danger; we may fairly assume this as a reason why the dura mater of the spinal column is only very loosely attached to the vertebral canal; on which account it allows of an accumulation of fluid on its external surface, such as we but rarely meet with in the brain. Owing to the firm attachment of the dura mater to the occipital foramen, fluids accumulated on this part are prevented passing into the cranial cavity, while there is a free communication between the arachnoidal spaces of the two cavities. This fact is one that must not be overlooked in morbid affections both of the spine and the encephalon; independent of the protection that the arachnoidal fluid affords to the cord, it is an evident means of securing a balance in the circulation in the nervous centres, while, on the other hand, a derangement in its quantity and site may be alone sufficient to produce serious symptoms, which the morbid anatomist would be unable to measure by physical tests. We possess no evidence of the occurrence of idiopathic disease of the spinal dura mater, though it can scarcely be supposed that a fibrous membrane, situated as it is, should not suffer from the rheumatic diathesis. In all cases of injury of the vertebral column it is liable to be affected, and scrofulous disease of the vertebræ and the extension of psoas abscess may involve it. In the congenital affection termed spina bifida, which is analogous to the form of hernia cerebri, occurring in infants as a result of non-closure of the cranial bones, the dura mater extends into the cyst that shows on the dorsal surface of the column; but it is occasionally found deficient at one point, so that the contained fluid is only retained by the thin meninges. This pathological state differs from that to which we have compared it in this, that the fluid is entirely external to the nerve-tissue, and that the cyst at no time presents a layer of medullary matter. The tumor varies in size from that of a small nut to that of a child's head; it generally is solitary, and occupies the lumbar or sacral region; when occurring in the back we may expect to find another tumor of the same description lower down. The swelling is of a semi-globular, or ovoid shape, and may appear pediculated, owing to a constriction at its base. The thinness of the cutaneous covering passing over the tumor, has induced some pathologists to deny its presence; this however is an error. The rarity of the occurrence of idiopathic diseases in the dura mater, applies equally to adventitious products. Encephaloid, and other forms of carcinoma, undoubtedly occur primarily in the dura mater, but in many of the instances on record, it is manifest that the disease extended from the bones to the theca vertebralis. The same is true with regard to tubercular deposits; in both cases, however, the membrane is liable to become secondarily involved, by extension of these diseases either from within or without the canal. An instance of melanotic growth apparently proceeding from the dura mater of the cord, is to be found in the Report of the Pathological Society for 1847. Dr. Williams discovered it in a patient, aged fortysix, who, three years previously, had suffered from hemiplegia of the right side, following the extirpation of the right eye, for fungus. The patient recovered from this, and in the summer preceding his death was attacked with epilepsy: weakness and numbness of the lower extremities, and inferior portion of the trunk, soon proceeding to complete paraplegia, supervened. The brain and its membranes were found healthy; within the spinal canal, closely adherent to the theca externally, there existed an irregular encephaloid mass, mottled with dark spots, extending from the third to the sixth dorsal vertebra, the bodies of which were carious and infiltrated with cancerous matter; the portion of the cord beneath the tumor was flattened, soft, and wasted. In connection with this subject, we may also be allowed to mention the very rare occurrence of an accumulation of fat, a genuine fatty tumor, within the spinal column, in contact with the dura mater; an instance of this kind was brought before the Pathological Society, in 1852, by Mr. Obré, in which death was produced in an otherwise healthy child by the Part of the dorsal portion of the spinal cord of a young man who died paraplegic. A thick layer of lymph and tuberculous matter was found surrounding the dura mater, and slightly compressing the cord. It was manifestly an extension of disease from the adjacent vertebræ and intervertebral cartilages. The cord and the dura mater appear healthy in texture. From St. Bartholomew's Museum, Series vii. No. 10. mere mechanical pressure exerted by a deposit of this kind. The lipoinatous growth was two and a half inches in length, the breadth of the canal, and about half an inch in thickness, composed of the ordinary spherical fat-cells: it did not differ from fat usually met with in other situations, excepting that the cells seemed to contain fat in a more solid and granular state. It lay between the theca and the bodies of the last cervical and first dorsal vertebræ. |