This form is decidedly the most frequent of all cerebral pernicious fevers. Its characteristic stamp is the coma. Naturally, gradations occur, and in isolated cases the disturbances of the sensorium may progress only to deep stupor, though these cases will be described as soporose pernicious.
The coma may come on suddenly, or be preceded by slight disturbances of the sensorium, like somnolence, psychic depression, apathy, melancholia, etc. Moreover, the coma may occur with the first fever paroxysm, or, as is more frequent, several paroxysms pass uncomplicated before it suddenly appears.
The coma may intermit-that is, begin with the rise in temperature, cease with its fall, and thus repeat itself. In these cases it is usually relatively short and seldom exceeds twelve to twenty four hours. In other cases-and these are the more frequent-the coma continues, with only occasional intervals of slight improvement, until death or recovery ensues. It may then extend over three or four days. It is not rare to see coma in the course of other varieties of pernicious fevers-for instance, typhoid pernicious or adynamic forms. It is associated with no definite type of fever. It may develop during an intermittent, quotidian, or tertian, as well as during a subcontinued.
The face is sometimes flushed, again pale or of a lead color; the latter is especially the case when the patient has become markedly anemic from repeated malarial infection.
The loudest summons calls forth no response or only an unintelligible mumbling. The swallowing reflexes are often abolished, or there is a cramp of the throat, so that neither nourishment nor medicine can be introduced per os.
The eyes are sometimes open, again shut; the balls frequently turned upward. The pupils are usually dilated, but may be contracted, and ordinarily react to light, even though sluggishly. The corneal reflex is commonly preserved.
The pulse is hastened, seldom slowed, sometimes full and compressible, again small and hard. It is usually regular; the opposite is significant of the approaching end (Dutroulau).
The breathing may vary in the same way, being sometimes hastened, again of ordinary frequency; it is often slowed and snorting. Irregularities in the respiration are frequent; occasionally Cheyne-Stokes' type occurs.
The skin is usually warm, and toward the end of the paroxysm bathed in excessive sweat. Not rarely isolated petechias are seen.
The limbs are, as a rule, completely relaxed. When lifted up, they fall back lifeless; yet not rarely they manifest, either now and then or throughout the whole paroxysm, irritative motor symptoms like extensor contractures or twitching of the extremities. To these may be added trismus, cramps of the muscles of deglutition, and deviation of the eyeballs.
The skin reflexes are markedly diminished, yet seldom abolished; some reflexes may be preserved while others are absent. The tendon reflexes are ordinarily intact. Evacuation of the bladder and bowels is involuntary; retention of urine is frequent.
The examination of the internal organs shows, besides the splenic tumor and the occasional increase of heart dulness, nothing abnormal. When certain symptoms on the part of the nervous system- paralysis, contractures, etc.-become prominent, we add the names corresponding to these symptoms-for instance, tetanic or hydrophobic, comatose pernicious (further details later).
With the cessation of the fever the coma disappears under profuse sweating. The patient may come gradually or at once to his full senses. Sometimes there exists for several days a condition of stupor, or apathy with somnolence, even when the temperature continues normal. With a renewal of the paroxysm the coma may recur.
When death occurs, it is usually under symptoms of cardiac insufficiency or paralysis. „Edema of the lungs develops, a cold sweat breaks out, the pulse becomes smaller and smaller. The termination is usually quite rapid and frequently unexpected. The temperature remains high, usque ad finem, and sometimes subfinem vitae rises to a hyperpyretic degree.
The blood from the peripheral vessels contains, especially as long as quinin is not administered, large numbers of parasites of the second group.* They occur sometimes in one single generation, when the fever is intermittent, or they manifest every stage of development, when the fever is usually subcontinuous. The latter is the more frequent. If quinin has been administered in sufficient doses, the number of parasites, as a rule, diminishes, yet in spite of this the severe clinical symptoms may continue, especially in cases in which the capillaries of the brain are filled with parasites, or in which nutritive disturbances of the brain substance or hemorrhages have occurred.
The diagnosis of comatose pernicious comes into question almost only in regions where severe malaria is endemic, yet it occasionally happens that persons who have been infected in severe malarial places depart from these and become ill elsewhere. The possibility, then, of malarial disease must be taken into consideration, even in places free from malaria , when the patient is known to have left a malarial region but a short time before.
A confusion of comatose pernicious with different diseases of the brain and with toxemias is naturally very easy, especially when the anamnesis is not complete. As a matter of fact, such errors in diagnosis are very frequent in malarial regions, where the physicians are inclined to perceive malaria behind most infections. It is usually cases of tuberculous meningitis, cerebral hemorrhage, or softening and uremia that come into question.
Reversely, it occasionally happens in places free from malaria that a pernicious coma does not arouse the slightest suspicion of malaria, and a corresponding error in diagnosis is made.
In addition to the enumerated anatomic diseases of the brain, sunstroke (insolatio) must be taken into consideration. This shows clinically considerable resemblance to comatose pernicious, and a further relation in another way, in that the effect of the sun's rays may produce an outbreak of comatose pernicious in people infected with malaria .
It would carry us too far to go into the differential diagnosis of these different diseases, and I omit it all the more readily since we possess in the blood examination the best means of diagnosing or excluding malaria . In comatose pernicious, especially so long as no quinin has been administered, we constantly find, even in the peripheral blood, large numbers of parasites and melaniferous leukocytes. If the blood finding is negative and there are, in spite of it, good grounds for suspicion, puncture of the spleen is justifiable. If the case is malaria , this must necessarily be positive.
* So far only two cases of comatose malaria have been observed, in which the blood showed the ordinary tertian parasites (French, Ziemann).
The prognosis in comatose pernicious is always very grave. Even after energetic treatment with quinin the mortality is large. Moreover, cases that show from the beginning a mild form may succumb in spite of the early administration of specific therapy. Even when the coma has passed, the prognosis must remain doubtful, since a second paroxysm may bring with it a recurrence of the coma.
A decrease in the number of parasites in the peripheral blood is in general a favorable prognostic sign, yet it sometimes happens that very few parasites are found in the peripheral blood, at a time when the cerebral vessels are packed with them. Again, the parasites may be absolutely eradicated by the quinin, yet the coma continue and lead to a fatal termination on account of cerebral disturbances of nutrition produced by the toxin of the parasites, or on account of anatomic changes (capillary hemorrhages) caused by the occlusion of vessels.
It is wise, therefore, even when the symptoms are yielding, to be guarded in the prognosis. Nor should we omit to take into consideration all the clinical symptoms, together with the blood picture in the prognostic calculation.