A CONTRIBUTION TO THE PATHOLOGY OF THE BRAIN.*

BY JOHN A. ROCKWELL, M. D.

THE pathology of the central nervous system has as yet been very little elucidated, for the simple reason that its minute anatomy has not as yet been fully understood.

The reticulum in the gray substance, first described by Gerlach of Erlangen, and by L. Mauthner of Vienna, twenty years ago, has been considered to be nervous in nature, as both observers saw this reticulum in direct communication with axis cylinders. Quite recently, however, this assertion has been contradicted by S. Stricker and L. Unger, who claim that the reticulum is an elongation of the pia mater, and therefore of connective-tissue

nature.

So far as my experience goes, I must coincide with the views held by Gerlach and Mauthner. I invariably succeeded in staining the reticulum of the gray substance violet with a solution of chloride of gold, the same as the nuclei which are scattered throughout the gray matter, and the ganglionic elements, whose nervous nature cannot be questioned. Moreover, I saw the reticulum in connection with axis cylinders, which we also know to be positively nervous elements.

It seems to me that the question, What is connective tissue and what is nervous structure in the gray substance? will never be certainly answered, as the connective-tissue offshoots of the pia mater, upon reaching the finest ramifications, lose their glueyielding basis substance and become protoplasmic in nature, the same as the nervous structure itself. Besides, a fatty degeneration, as also a waxy or amylaceous degeneration of the ganglionic nerve elements, is known to occur. C. Wedl, of Vienna, was the first to maintain that a waxy degeneration may also invade the capillary blood-vessels, resulting in the formation of shining homogeneous cords, ramifying like blood-vessels and freely supplied with pedunculated, bud-like, stratified projections.

The amylaceous corpuscles have, for a long time, been known to occur in the gray substance of the central nervous system, where they represent bright, stratified, apparently structureless masses, containing sometimes in their central portion an unaltered plastid† Such corpuscles are so common both in the gray substance of the brain and the spinal cord, and in the arachnoid of each, that some histologists have asserted that they

* Read before the New York Homeopathic Medical Society, Albany, Feb. 14, 1882. †The word plastid has been used (suggested by Dr. L. Elsbery, of this city, and adopted by Heitzmann and others) for a lump of living matter, in place of cell, etc. VOL XVII. — NO. 3.

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were normal formations,- for instance, Frey, of Zurich. They occur either singly or in double or multiple formations, clustered and partly coalesced.

Their designation "amylaceous" originated with Virchow, who, upon applying iodine and dilute sulphuric acid, could in some instances produce a bluish tinge of these corpuscles. Upon the authority of Virchow the name "amylaceous corpuscles" has been accepted, although the bluish color after treatment with iodine, which feature reminded Virchow of starch corpuscles of plants, by later observers could not, or only in a very slight degree, be produced. Evidently, the bluish color, wherever it occurs, is nothing but the complementary color of these highly refracting bodies to the yellow-brown neighborhood after the application of iodine. I consider this reagent of no value.

What the intimate nature of the amylaceous corpuscles, or the waxy degeneration in general, is, we do not know. Dickinson, of London, maintained that the waxy material is dealkalized fibrine; but the assumption is merely hypothetical, and not as yet chemically proved. This much is certain, that the formation of these corpuscles, as well as the waxy degeneration itself, is closely connected with chemical alteration of the plasma of the blood, inasmuch as in almost all instances the waxy change is known to first invade the blood-vessels. In the spleen and the kidneys the muscle coat of the small arterioles is, as a rule, the first to exhibit the waxy change. In the brain the capillaries are unquestionably the first invaded formations, as recently proved again by J. Baxter Emerson, of New York, in his able paper, "Periencephalitis" ("Journal of Nervous and Mental Diseases," April, 1880).

This observer, in one case of encephalitis, observed in both hemispheres of the cerebellum "ramifications, closely resembling those of the capillaries, with sharp, well-defined, fluting outlines, colorless and of a high refracting power. Such groups were found principally in the granular layer, but extended somewhat into the contiguous layers. There were also numerous isolated, highly refracting bodies scattered throughout the whole cerebellum, but mainly in the granular layer. With the higher power of the microscope, peculiar changes of the capillaries were shown; namely, the capillaries were transformed into either single or double rows of brilliant, colorless globules, or completely transformed into a glistening, rod-like mass, with fluting outlines and numerous partly pedunculated buds." "Exceptionally," Emerson says, "I found the cells of Purkinje, with their offshoots, presenting the same glistening, highly refractive appearance as the capillaries and the corpora amylacea."

The case from which my specimen has come was one for two

years under the care or observation of Dr. E. H. Linnell, of Norwich, Conn., and published in the " Archives of Ophthalmology," Vol. X., No. 4, December, 1881.

"Mr. T, aged sixty-three, of nervous temperament and thin habit, first consulted me," says Dr. Linnell, "for failing vision, in November, 1879. His avocation had been that of a photographer, until ill health, which he attributed to the constant handling of chemicals, obliged him to relinquish it. Inquiry elicited the following facts: For the past eight or nine years he had been subject to frequent attacks of neuralgia, affecting his head and limbs; he had been habitually constipated; his urine had been somewhat increased in quantity, light-colored, and passed frequently; and for four years he had had paralysis agitans affecting his right arm and leg, but more markedly the arm. This tremor developed gradually, and was attended with partial anæsthesia, denoted by numbness and tingling sensations in the affected limbs, and by general debility. In other respects he enjoyed good health until the fall of 1879. During the night of Sept. 27 of that year, he had a sudden severe attack of pain in the head, extending from vertex to chin, accompanied by total blindness, and followed by vertigo, nausea, and slow pulse. Digitalis was prescribed, and after twenty-four hours the intensity of symptoms was moderated, and his sight began very gradually to be restored, but was never fully recovered. He continued to suffer with neuralgic headache and vertigo, and his gait became halting and uncertain. His mental faculties, however, remained unimpaired, and the paralysis agitans, or the difficulty of locomotion, did not increase. When I first saw him, VOU=3, refraction Em. He had, however, left-sided binocular hemianopsia. . . . In the latter part of April, 1880, he had another sudden attack of complete blindness. This attack was unattended by pain, and was of shorter duration than the first." During the following year, Dr. Linnell says, "his sight seemed to fail gradually, until he could with difficulty distinguish large objects. He complained much of dizziness, but suffered less pain; walking became more fatiguing, the right leg seeming heavy, and as if too long. He retained the use of all his faculties, and could converse intelligently, although his mind seemed to lose some of its natural vigor. In the latter part of June, 1881, he was suddenly seized with a general tremor of the whole body, afterwards becoming more pronounced upon the right side. This was not attended with pain, and he apparently recovered from the effects of it; but had a similar seizure, July 2, accompanied with constriction of the post-cervical muscles. The rigidity increased, he soon became unconscious, and was apparently entirely blind. After a few hours he

partly regained consciousness, and had perception of light. From July 4 to 8, he seemed to improve somewhat. From this time he gradually failed both in intellect and strength, until he became comatose, in which condition he remained for several days, and died July 19."

An autopsy was held in the afternoon of the day of his death, with the following result:

“The dura mater was so firmly adherent that the calvarium could not be removed without cutting through it; and in so doing, several ounces of dark fluid blood escaped from the sinuses. Both it and the arachnoid appeared healthy. The pia mater was much injected, the veins being distended with dark blood. The entire weight of the brain was 2 pounds 151⁄2 ounces. The cortical substance of the cerebrum was of normal consistence; but upon section of the right hemisphere, a large and firm coagulum was found in the medullary substance. It was nearly circular, and measured approximately 4 cm. in diameter and 2 cm. in thickness. It was situated a little anterior to the centre of the hemisphere, and did not anywhere encroach upon the cortical substance. The contiguous brain substance was softened for a thickness of about two lines, but the clot was removed almost entire, and there was no serum, pus, or other indication of inflammation or of extensive degeneration. No pathological changes could be discovered in the left hemisphere. The fluid in the ventricles was not appreciably increased in amount, although there was more serum upon the left than upon the right side. The velum interpositum and choroid plexuses of the ventricles were highly vascular, the veins being turgid and swollen, and this was more marked upon the left side. The tubercula quadrigemina were manifestly degenerated, and presented the appearance described as white softening. This condition was much more evident upon the left side, but it was not limited to these bodies. It also extended laterally and anteriorly, involving the corpora geniculata, the posterior and inferior portions of the optic thalamus on the left side, and also, to some extent, the floor of the fourth ventricle. A portion of the left optic tract and the adjacent under surface of the thalamus was removed for microscopical examination. This was so soft as to require very careful handling to prevent crushing."

Dr. Linnell kindly sent me a portion of the under surface of the left optic thalamus, which came to me a few days after it was removed from the corpse, preserved in alcohol. The specimen exhibited a grayish-yellow discoloration, as if fatty. It was placed in a very dilute (one fifth per cent) solution of chromic acid, and after a few days was sufficiently hard to be sliced with

a razor. The sections were mounted in glycerine, and even those which went through the treatment with alcohol and oil of cloves were again introduced into water and mounted in dilute glycerine. Incidentally, I wish to say that for three years I have been pursuing microscopical studies in the laboratory of Dr. C. Heitzmann, of New York, and by repeated trials have become convinced that the mounting of specimens in glycerine is far superior to mounting in Canada balsam or Damar varnish. Comparative mountings in these liquids, especially for specimens of the nervous centres, have resulted in the conviction that the balsam or varnish mounting ought to be wholly abandoned. Unquestionably one, if not the main reason why our knowledge as to the pathology of the brain and the spinal cord has progressed so slowly for the past twenty years, is the mounting in balsam. By this method, the specimens in a short time clear up to such an extent that the minutest details fade, and the specimens become unfit for research with high amplifications of the microscope (800 to 1,200 diameters), which are the only possible means of revealing the minutest normal as well as pathological features.

WAXY DEGENERATION OF THE GRAY SUBSTANCE OF THE THALAMUS OPTICUS AT 800.

V. Capillary blood-vessel, containing a granular mass, compressed at its upper portion, surrounded by a layer of the waxy mass.

G. Gray substance, the meshes of the bioplasson enlarged by the waxy material, which collects into branching, irregularly contoured, shining fields, W1, W2.

N. Nucleus of the gray substance; a part of the periphery, surrounded by a waxy mass.