Complete Text (Part 8)

of special importance to note the amount of blood in the body as a whole, as well as in its several parts or organs. I. EXAMINATION OF THE SPINAL CANAL. In order to reach the spinal cord a deep incision should be carried along the spinous processes of the vertebrae, and the tissues then freely dissected off from the laminse. Thus we are enabled to look for — (a.) Morbid conditions of the soft parts, and hones as far as exposed (in medico-legal cases fracture must be borne in mind). We have already discussed the changes which may be found in the soft parts, and general modifications of the vertebrae themselves will receive consideration in detail later on ; we are now concerned with those changes which are confined to the spinous processes and arches of the verte- bra. The chief of these is a congenital idefect in the laminae which have not reached the median line in their development, so that the spinous process and a larger or smaller portion of 42 DIAGNOSIS IN PATHOLOGICAL ANATOMY. the laminge are wanting. This condition may be confined to one, or involve several vertebrae, and is called spina bifida. In adults it is found only in the lumbar or sacral portion of the column, and is of limited extent ; in young children its localization is generally the same as in adults, but its extent is greater. A fissure of this kind in the upper portion of the column is commonly connected with the condition known as anencephalia, which will shortly demand our consideration. The higher degrees of spina bifida are always associated with gross changes in the cord and its membranes. Next, by means of a chisel or a rachitome, the spinous processes and adjoining portions of the lamina should be detached and removed. (5.) The thickness (translucency), degree of tension, color, and amount of blood in the exposed dura mater should now be noted, it should then be carefully opened by a longitudinal incision and the presence of any abnormal contents, especially fluid (cerebro-spinal fluid, pus, blood), noted. Next the con- dition of the posterior surface of the pia mater as to thick- ness, tension, color, and amount of blood should be noticed, and the resistance of the spinal cord estimated by drawing the finger along it with gentle pressure. The roots of the spinal nerves should next be severed on either side, the lower end of the cord gently removed from its bed with the hand, its anterior attachments divided one after another, and, lastly, it should be divided obliquely as near the occipital foramen as possible ; or simply extracted in case the brain has already been examined. Throughout all these procedures great care should be exercised neither to compress the cord, nor to bend it at a sharp angle, and, in case the cord is very soft, it is often safer to avoid touching it directly, but to remove it together with its dura. After removal, the condition of the anterior por- tion of the pia, the external appearance of the cord as to size and color, and, finally, the internal condition of both the white and gray portions should be noted, cross sections being made at frequent intervals with a sharp and thin-bladed SPINAL CANAL. 43 knife, which should be dipped in water before each cut. The dura should then be separated from the bodies of the ver- tebms, unless this has already been done, and haemorrhage, injury to, or disease of, the bones and intervertebral disks should be sought for. In examining the spinal cord attention is first to be directed to its — (a.) General Appearance. Modifications in color^ especially in the columns of the cord, should be carefully examined into, since they may be simulated by inequalities in the surface of the section and peculiarities of illumination ; it is important for this reason to examine both cut surfaces, and to let the light fall upon them from all directions in turn. Although actual modifica- tions of color may be thus made out with tolerable accuracy, it must be remarked that it is very difficult to decide as to the exact significance of such modifications, and that even a very experienced observer may be deceived into regarding as normal, portions of the cord which the microscope shows to be diseased. Hence one should never neglect a microscopical examination, which is very readily made w^ith sufficient thor- oughness for diagnostic purposes. It generally suffices to snip out a bit with scissors, tear it up with needles, and flatten it with a cover glass. (5.) Sptecial Morbid Conditions. The special structural modifications of the parts enumer- ated above are so similar to those of the brain and its mem- branes that, for the sake of simplicity, we refer the reader to them. 1. The spinal differs from the cerebral dura mater chiefly by not being at the same time enveloping membrane and periosteum, but only the former. Hence it is never the sub- ject of bone-forming or ossifying inflammation so common in the cerebral dura mater. Pachymeningitis interna hgemor- rhagica is not nearly so frequent in the spinal as in the cere- bral dura ; but the other forms of inflammation, both ex- ternal and internal, occur with nearly equal frequency in 44 DIAGNOSIS IN PATHOLOGICAL ANATOMY. both. Haemorrhage is not so common, on account of the protected situation occupied by the cord ; but chronic in- ternal inflammations, attended with the formation of very small fibrous nodules, closely resembling tubercles, are, on the contrary, rather more common. These nodules may be- come calcified and thus form little bodies like grains of sand (pachymeningitis arenosa) which, when aggregated together in larger masses, are called psammoma. 2. Inflammatory changes in the spinal, are similar to those in the cerehr&l pia mater ; but are, in general, less commonly met with. Arachnitis ossificans alone is more common in the spinal pia, and results in the formation of bony plates with smooth external, and jagged internal surfaces. The veins of the pia are usually more distended with blood in its posterior and inferior portions, in consequence of the position in which the body is generally laid. 3. The cord is liable to much the same sort of affections as the brain, but not with the same degree of frequency ; this remark applies particularly to such processes as soften- ing, and is not to be wondered at when one considers how much better adapted to the establishment of collateral circu- lation the vessels of the cord are than those of the brain. Thus inflammation or myelitis, red, brown, and yellow softening, and hsemorrhage are all found ; as are also new growths of all kinds, including the so-called solitary/ tuber- cles, so beautifully concentric in structure. There are, how- ever, a few affections which are either sufficiently common, or so peculiar in appearance as to call for detailed description. Chief among these is the anatomical lesion of locomotor ataxia, gray degeneration of the posterior columns of the cord, posterior spinal sclerosis. In well marked cases of this affection a gray stripe on either side of the posterior median fissure is visible even through the pia, and these stripes are usually more distinct inferiorly than superiorly (^ascending degeneration). On section, either the whole or a portion of the posterior columns — generally those portions adjacent to the median fissure, the posterior median columns (Goll's SPINAL CANAL. 45 columns) — are seen to be of a transparent gray, or rather brownish-gray, color ; they are hard, and depressed below the level of the neighboring portions. Changes are almost always found in the posterior roots also, which are gray (non- medullated} and atrophied. The microscope shows in needle preparations an abundance of fibrous tissue, but few raedul- lated nerve fibres, and many of the so-called corpora amyla- cea — rounded little bodies concentric in structure, which be- come brownish on the addition of iodine, and blue on the ad- dition of sulphuric acid. Chronic spinal arachnitis, which, according to Virchow, is the excitant of the process found in the cord, is always associated with this affection (jneningo- myelitis corticalis inter stitialis). Disseminated gray degen- eratio7i, also called insular sclerosis, disseminated sclerosis, antero-lateral sclerosis, is an affection of another nature and is not confined to the posterior columns, but may even occur in the brain. Microscopically this affection only differs from that before described in that it is not uniformly distributed, and thus the cord appears nodulated, the nodules indicating relatively healthy tissue. The microscope is said to show more signs of inflammation — thickening of the walls of the vessels, etc., — the absence of corpora amylacea, but a more active cellular growth in the neuroglia and the formation of granular corpuscles (^Rindfleisch). There is, finally, a third kind of degeneration — descending or secondary degenera- tion, so-called, — which causes discoloration of the white matter ; this is an atrophy of the lateral, and particularly of the posterior lateral, columns, and is secondary to local cerebral lesions. The diseased portions are rather grayish yellow than gray in color, are very soft, and non-transpar- ent. Needle preparations show, when placed under the microscope, numerous granular corpuscles and fatty degen- erated nerve fibres. The same changes are found both above and below those local lesions of the cord which are accom- panied by destruction of nerve fibres. There is, finally, a congenital condition, called hydromen- ingocele to be mentioned, the cause of the previously de- 46 DIAGNOSIS IN PATHOLOGICAL ANATOMY. scribed spina bifida. This consists in a sac of variable size, the wall of which is formed by the skin and the membranes of the cord, and is traversed by the roots of the nerves, while the cord itself is contained within the sac. The sac contains also a clear, watery fluid, and the whole affection starts from a collection of fluid in the network of the arachnoid. The usual seat of the affection is the sacral and lumbar regions, and it has been known to persist into adult life. When seated higher up it is called hydromyelocele ; it is here gener- ally due to dilation of the central canal, and involves com- plete disorganization of the cord at that place. II. THE CRANIAL CAVITY. In medico-legal cases attended with injury to the head the seat of such injury should always be disturbed as little as possible, and the best method of opening the head varies ac- cording to the individual peculiarity of the case in hand. Ordinarily, however, the best method is to carry the knife through the scalp in a line over the vertex from one mastoid process to the other ; and then to reflect the soft parts for- ward as far as the superciliary ridges, and backward behind the external occipital protuberance. (Changes in the soft parts have been already described.) The pericranium which is thus laid bare should now be ex- amined as to thickness, color, consistency, and continuity, and the periosteum should then be scraped off with a chisel or periosteum-scraper so as to expose the bony vault of the skull. The ordinary affections of periosteum and bone will receive but brief mention here, as they will be discussed in detail under Bones of the Extremities. We shall confine ourselves therefore chiefly to those changes which are pecul- iar to the skull and its periosteum. 1. MORBID CONDITIONS OF THE PERIOSTEUM. The various forms of inflammation may be found (ossify- ing, purulent, and gummy periostitis), as also hsemorrhage, CRANIUM. 47 etc. Under the head of h£emorrhage are inchided those col- lections of blood between the pericranium and the bone which are sometimes found in new-born children — ceplial- hcBmatoma neonatorum. The tumor thus formed is usually limited to the region of the right parietal bone, never ex- tends across the sagittal suture, and after a certain lapse of time becomes surrounded by a bony wall — the result of os- sifying periostitis. Still later, small plates of bone, which at first have no connection with each other, make their ap- pearance on the more elevated portions of the tumor and thus the whole tumor may become encapsulated. Sometimes in- stead of blood the tumor contains a reddish-yellow puriform mass, which indicates that suppuration has taken place. 2. EXAMINATIOlSr OF THE BOKE FKOM WITHOUT. (a.) Greneral Appearance and Character. 1. The size of the skull varies widely in different indi- viduals. Very large skulls with prominent frontal bones are generally associated with and caused by hydrocephalus. 2. The/orm of the skull is for many reasons more impor- tant than its size ; though it, too, is subject to great varia- tions. In modern times the influence of race on the form of the skull has received much attention, and a heated con- troversy has arisen as to the relative significance of " long heads " and " short heads." One should never neglect, therefore, to measure both the transverse and longitudinal diameters. In a mesocephalic skull the transverse stands in an average ratio to the longitudinal diameter of 70-80 to 100 ; if the transverse diameter fall short of this the skull is called doUcliocephalic ; if it exceed this it is called hrachycephalic. The symmetry of the two sides of the skull is of greater pathological interest. Oblique asymme- try is called plagiocepTialia. The chief classes into which abnormally shaped skulls have been divided are as follows : the platycephalic skull, with small vertical and large transverse diameters ; the oxy- cephalic, with large vertical and small transverse diameters ; 48 DIAGNOSIS IN PATHOLOGICAL ANATOMY. the scapliocej)lialic, in whicli the parietal bones incline to- ward one another like the sides of a roof ; clinocephalic, with saddle-like depressions in the temporal regions ; spheno- cephalic, with wedge-like prominence of the region of the great fontanel. 3. The normal color of the external surface of the calva- ria is gray, or yellowish-gray (if there be much fatty marrow in the diploe), and but few red points are to be seen. Mor- bid processes in the bone or periosteum may give rise to a more or less uniform and pronounced reddish hue ; a circum- scribed lemon-yellow shade is associated with gummata, a dirty greenish-yellow or slaty shade with osteomyelitis, etc. 4. The chief affection attended by modification in the con- sistency of the bones is craniotabes or soft occiput, in which the bone becomes flexible like parchment ; this is one of the manifestations of rickets. Sometimes the cranial bones of adults are more or less softened and replaced by connective tissue in connection with tumors, epithelioma for instance. The sutures should always be carefully examined on ac- count of the part which they play in the development of the skull. All the above mentioned modifications in the form of the cranium are dependent on premature synostosis of the sutures in whole or in part. A suture is to be regarded as existent so long as its delicate zigzag lines are visible. Con- trasted with premature ossification of the sutures is partial or complete persistence of the frontal suture, which normally disappears at the end of the fifth year. Small bones called ossa triquetra or Wormian hones are often found imbedded in the sutures, particularly in hydrocephalic skulls ; they are more common in the occipito-parietal suture than elsewhere. Sometimes they result from independent ossification of a fontanel, and are then called fontanel hones. The OS Incae, as found in old Peruvian skulls, is due to separation of the tabular portion of the occipital bone by a suture. (5.) Special Morbid Conditions. Of the special morbid conditions to which bone is liable CRANIUM. 49 there are but few which are peculiar to the skull or appear there in a peculiar form. Atrophy may depend on pressure, by tumors, etc., on the process of involution, as in senile atro- phy, which first takes place at the parietal eminences and may result in complete absorption of the bone, or in actual disease of the bone. In atrophy of the external surface of the skull the openings for the transmission of vessels assume greater prominence and, in consequence of this, the atrophied portions are indicated by red spots. The neio formation of hone is very common and may ap- pear under a variety of forms, but every bony prominence must not be considered as a new formation, since the bone may also be elevated by a growth at its inner surface — a Pacchionian body, for instance. Even in this case a new for- mation of bone may be said, strictly speaking, to take place, new bone being deposited externally as the old bone is ab- sorbed from within ; bone which has reached its full develop- ment is non-distensible. There is an irregularly distributed form of external hyperostosis which is found associated with numerous irregularly shaped indentations of the skull and is nearly always of syphilitic origin ; in recent cases of this nature the diagnosis of syphilis is confirmed by the presence of masses of a soft and yellowish or gray substance between the hyperostoses. Fractures of the skull, which may be of very great im- portance medico-legally, can, as a rule, be better studied on the inner surface of the skull, for the reason that, whether attended with depression or not, the injury of the inner is greater than that of the outer table ; old fractures which have been entirely recovered from are sometimes found. When the examination of the external surface has been completed,^ a circular incision should be made down to ^ In cases in which there is no reason to expect changes in the calvaria it is more convenient to have the bone sawn through beforehand by an attendant ; but even then the points which we have enumerated above, and especially those which bear on the form of the skull, should