The writer has before him a beautiful speci men of this abnormal condition, for the oppor tunity of examining which he is indebted to Dr. E.W. Murphy, as well as for permission to have a drawing taken from the preparation in his possession. (Scefig. 199.) The opening in the diaphragm in this case is at the left side, rather anterior to and to the left of that which naturally transmits the oesophagus, and appears to arise in this case from separation of the fibres of the muscle ; a very large quantity of the small intestine is lodged in the left side of the thorax, from which the heart is pushed away over to the right ; the right lung, which lies behind the heart, is natural in structure, but the left does not equal in size half the kernel of an almond, and does not possess the natural pulmonary structure, but appears nearly as solid as the liver. The stomach, spleen, and liver were in their natural situation. The child had also a spina bifida tumour which covered the whole of the sacrum, and deformity of one hand, the thumb of which was attached by a small pedicle to the side of the index finger. In a case related by M. le Doctcur Anthony,• which occurred in his practice, the child, which lived occipitis, as in Dr. Collins's case, to be noticed presently ; but it has happened to the writer to observe it more frequently in the other situa tions above mentioned. In one of the cases related by Mr. Adams, it occurred just over the right eye, and the subject of it had reached his twentieth year when the account of his case was published. (See fig. 150.) half an hour, had no external appearance of any thing abnormal; but, on examination after death, the left side of the diaphragm was found not to exist, and the small intestines and spleen were contained in the thorax ; in all other respects the condition of the child exactly resembled that described above.* Hernia cerebri or encephalocele.—The af fection to which these names are applied is not of unfrequent occurrence in the fcetus. It con sists of a tumour protruding from the cavity of the cranium through an aperture in the bony structure, covered externally by the integuments, lined internally by the dura mater and arach noid, and containing portions of the cerebrum or cerebellum, together with serous fluid, with which the cerebral structure is in general infil trated and softened down ; sometimes the con tents of the tumour appear to be completely fluid.
This affection is most frequently situated on some point of the central line of the head, commencing at the root of the nose and ter minating at the foramen magnum of the occi pital bone ; these being the situations in which the fcetal head, during a considerable period, consists only of membrane; the writer has seen it in the centre of the forehead at the anterior and posterior fontanelle and in the centre of the occipital hone. According to the observa tions of Mr. Adams,t the tumour is most fre quently situated at some point in the middle line of the proper occipital portion of the os In such instances the bony vault of the head is usually much smaller than in ordinary cases, being proportioned to the diminished quantity of its contents, and the sutures and fontanelles are found closed.
In the first case of this affection which came under the writer's notice, a tumour, about the size and somewhat of the shape of a fresh fig, hung from the centre of the child's forehead down over the face ; it was only partially filled, and apparently with a gelatinous fluid ; when compressed towards the forehead the contents were diminished, but, in the same proportion, the child appeared distressed, and the features began to be distorted, the vault of the cra nium was in a great measure deficient of its proper developement, the parietal and frontal bones rising very little above the base of the cranium, when they turned over to form the roof of the skull. The child did not present
any other external deviation in form; it lived ten days, taking food, digesting, and perform ing the other common functions like other chil dren, but then pined away and died. On exa mination after death, it was found that the bag which had protruded and hung over the face was lined by the dura mater and arachnoid, that the cerebrum was entirely absent, as was also part of one side of the cerebellum ; the aperture in the frontal bone, through which the hernia passed, was situated just over the root of the nose, in the line of the suture, was about three-sixteenths of an inch in diameter, and with smoothly rounded edges; the sutures and fontanelles were quite closed up. M. Moreau, not long since, presented a nearly similar case to the Academy of Surgery at I'aris.
In another case, the east of which was sent to the writer by Dr. Cason of Enniskerry, the hernia appears to have taken place at the ante rior fontanelle. J. Cloquet met with a case where it protruded through the posterior fonta nelle.* A remarkable case of this affection, occurring in a very unusual situation, was ob served at the Hotel Dieu at Paris : a child of about a year and a half old was admitted on account of a small tumour, supposed to be a ganglion, about as large as a nut, and situated at the root of the nose, exactly under the nasal process of the frontal bone. At birth it had been only as large as a pea; it was increased in size, and became redder when the child cried; the child was very irritable; pressure on the tumour gave pain, and produced a general agitation. Dupuytren suspected that the tu mour was formed by a prolongation of the brain through some congenital opening in the base of the skull, and on consulting with M. Breschet, the latter declared that he had met with a precisely similar case, in which, on dissection, he had found that the tumour was formed by a portion of one of the anterior lobes of the brain, which was prolonged through a slit in the centre of the ethmoid and sphenoid bones down to the root of the As tumours of a very different character are frequently observed OD the foetal head at birth, it is of consequence to be satisfied of the diagnostic characters of the encephalocele, which is at first a rather tense, smooth, and semitransparent tumour, giving generally a more or less distinct sense of fluctuation ; it afterwards collapses and becomes wrinkled and smaller in dimension ; the integument over it is thin but not discoloured, not unfrequently pale : in shape the tumour is globular or oval, and frequently tapers to a neck where it issues from the head, (seefig.151,) at which point a circular aperture can be detected in the bone, the edges of which are in general smoothly rounded off; the tumour is not painful, but, if it be compressed by the hand, so as to cause a considerable diminution in its volume, the child appears to suffer much distress, sometimes has the features slightly convulsed fur the mn ment, and is rendered stupid and paralytic, as under other circumstances of cerebral oppres sion; pulsations are to be felt in the tumour synchronous with those of the heart; and, lastly, the volume of the tumour is suddenly increased by any effort on the part of the child, as by coughing, straining, crying, &c.