LIV.

THE CAUSES OF PUERPERAL ECLAMPSIA.

BY RACHEL T. SPEAKMAN, M.D., BATTLE CREEK, MICH.

Of the many obscure questions claiming the physician's attention, few are less clearly understood than the one under consideration, and inquiry into these causes leads through labyrinths of research, in which doubts and disagreements are much more prevalent than well-authenticated facts.

Teachers and writers in treating the subject divide the causes into two general classes, which they designate as centric or proximate and eccentric or remote. The first includes those that induce convulsions by direct irritation to the nervous centres. The second those that are more external, and their influence · reflected.

The centric causes may be either physical or psychical. The physical acting upon the brain and its membranes, and upon the spinal cord and its membranes, and termed intracranial and intravertebral causes.

The psychical are those acting upon the emotional portion of the organism.

The eccentric causes are those which excite and irritate the incident nerves.

Prominent among the first causes are sanguineous derangements, such as blood-clots, serous effusions, etc.; anything producing immediate pressure upon the brain and its appendages; or, on the contrary, anything that removes the normal pressure, as does severe uterine hæmorrhage.

First and most frequent among the second causes are such conditions as directly irritate the uterus and its surroundings,

among which are pressure of the presenting part of the child, change of its position in the early stage of parturition, overdistension of the uterus by internal abnormal growths, or the presence of two or more foetuses, an unnatural amount of amniotic fluid, large quantities of hardened fecal matter, etc. These and numerous like conditions are familiarly cited as causing puerperal eclampsia.

But why blood-clots in the brain or spine, why chemical poisons in the blood, why a sense of shame, a disturbing look, an emotion of grief or thrill of joy, should produce these alarming and often fatal convulsions, are questions awaiting clearer solution.

Why moral and mental emotions, etc., produce local congestion sufficient to induce them, involves a more intimate acquaintance with the process of nervous operation than has yet been attained. Many and ingenious are the explanations advanced and accepted, but on close examination they all reveal more theoretical than positive knowledge.

Since no convulsive action can be produced without irritation. of the motor apparatus of the nervous system, it must be through an understanding of the mechanism of that, that we can hope to arrive at anything like a correct solution of the nature of these phenomena. In view of this the motor tract, with its contained hemispheres, corpora striata, cerebellum, pons varolii, and medulla, as well as the cells found in the gray matter of the spinal cord on its anterior portion, claim close study, but involve too lengthy detail for presentation here.

Herman Nothnagel, in his extended experiments on the nervous system, has demonstrated the existence of a "special convulsive centre," situated in the pons, and found (Erb thinks) in that portion where the motor nerves of the antero-lateral column first terminate in ganglion cells. Irritation, direct or indirect, of this circumscribed spot, gives rise to convulsions of an epileptiform type. Extreme anæmia of this convulsive centre is also considered by Erb a cause of widely-extended and violent convulsions.

The possibility of sometimes causing epileptic seizures by pressure on certain portions of the body, leads to the inquiry,

whether eclampsia may not also be so caused in some cases. The existence of pressure-points, so clearly proven by the experiments of Von Graefe and Hitzig, make it plausible at least. If pressure at points as distant as the vertebral column and joints of the wrists and hands will cause or prevent convulsions, why not reasonably infer the uterus a most important pressure-point during the parturient period, and the unavoidable pressure attending labor as sometimes cause in itself sufficient to induce puerperal convulsions?

The eclamptic seizures during gestation, uncomplicated with kidney affections, are thought by Wernich to be caused by pressure of the enlarged uterus upon the sciatic nerve. Claiming that this pressure may cause, as does injury of the same nerve in the Guinea pig, increased irritability in the pons and medulla, and that if to this irritability is added irritation of the sensory nerves of the sexual organs, these convulsions result.

Increased motor activity is the general accompaniment of all convulsive action, hence any mechanical or other stimuli, calenlated to provoke greater activity of this system of nerves, may, under certain conditions, induce eclampsia.

Prof. Braun claims that "eclampsia is an acute affection of the motor functions of the nervous system, and occurs only as a phenomenon of some other disease, which, under certain conditions, propagates its toxæmic effects on the brain and nervous system," and pronounces Bright's disease of the kidneys the one most frequently giving rise to "these frightful accidents." But, unless albuminuria had been detected before gestation, we could not be positive that the patient was suffering from Bright's disease in some of its stages, any more than would be the case in convulsions arising from albuminuria in scarlet fever. In both instances the renal disturbance may be only temporary, and the speedy return of the kidneys to normal, healthful action, almost precludes the idea of the presence of that disease.

Dr. Hodges, after large experience and thorough investigation, does not hesitate to say there is no essential pathological difference between the usual form of puerperal convulsions and those of a hysterical type occurring in the non-pregnant state, and thinks the only difference is in the degree of congestion. Other

able investigators take the ground that the pathological condition of all convulsions is the same, and that "eclampsia is only an acute form of epilepsy."

If these three forms of convulsions are one and the same, except in degree of congestion, may it not be quite possible that, in woman's mode of dress, exists a cause for many of the convulsions with which we meet during the gestative and parturient periods?

VASCULAR CONGESTION OF THE KIDNEYS.

One great source of albuminuria, that most popularly accepted cause of puerperal convulsions, if induced by pressure of the gravid uterus upon these organs, must be greatly increased by a style of dress that calls for from three to five more thicknesses of clothing over this region of the body than is worn over the extremities; and the still further addition of an unwieldy corset, always stiff and mostly tight, increases the trouble by overheating and unduly compressing all of that portion of the body in which, as it were, the very engines of congestion are located.

This pressure, interfering with the free return of the venous blood from the kidneys, gives the urine less than its normal amount of urea, and the blood is freighted with an excess. This pressure on the thoracic and abdominal viscera interferes with the proper oxidation of the blood at a time when the eliminating organs are called upon to perform extra duty; for, in addition to eliminating the debris of the maternal system, they have that of the foetus; thus is thrown into the circulation an amount of effete and poisonous matter, enough, with other deranged conditions, to induce convulsions.

In pregnancy, even when natural, the condition of the blood is not identical with that of the non-pregnant state. The increase of the number of white corpuscles renders smaller the proportion between these red and white constituents of the blood, which is one of the essential characteristics in anæmia. This alteration produces changes in the nutritive processes which result in added irritability of the nervous system, rendering it more excitable, and "emotional excitability," Dr. Barnes maintains, "measures convulsive liability."

Another condition of gestation is increased frequency and force of the heart-beats, resulting in consequence of the pressure made upon the abdominal aorta and its pelvic divisions by the growing contents of the uterus.

This frequency and force are greatly aggravated by the undue pressure exerted by tight-dressing, and its continuance results in cerebral arterial tension; another condition giving rise to these convulsions.

How much influence such pressure may have upon the pressure-points" so frequently spoken of by Erb, Hitzig, Von Graefe, and others, is not yet demonstrated; but with a convulsive centre, and these points as important pivotal facts, may we not reasonably hope for more definite knowledge regarding the causes of these convulsions,-convulsions so terrible in their manifestations as to cause the brave and hopeful Dr. H. N. Guernsey to say they were the only thing connected with his profession that ever made him regret being a physician,—a feeling in which all must sympathize who have any conception of that with which they have to contend when called to a patient suffering an attack of eclampsia, and around the causes of which cluster so much doubt and disagreement that all must acknowledge, in relation to them, "the book of revelation is not yet finished."