This is frequently encountered in mild form in fevers both of the first and second group. Yet it sometimes happens that the psychic disturbance is so marked as even to dominate the picture. The delirium may continue throughout a paroxysm or occur only as an introduction to coma.
Kelsch and Kiener divide it into three forms: The first is characterized by violent symptoms, loud cries, maledictions, laughing, and raging. In this form the eyes are injected, stand out; the skin is burning hot. In all these cases they found either insolation or pneumonia as a complication. The second form expresses itself in a fixed idea that is usually gloomy. The patient is in a condition of deep mental depression and endeavors to run away, to throw himself from a window, etc. The third form is characterized by delusions and hallucinations, among which ideas of grandeur, religious notions, and delusions of persecution predominate. The patient may be quiet, distrustful, gloomy, or maniacal. The fever is relatively insignificant. This form continues the longest. Kelsch and Kiener observed one case in which the delirium continued about a week after the paroxysm.
Pasmanik, who saw a very large number of cases, never observed actual mania, but always conditions of depression, usually in the form of melancholia agitata or melancholia simplex.
Since Kelsch and Kiener noticed in their cases with maniacal symptoms the previously mentioned complications, we may conclude with Pasmanik that when malaria does act on the psychic functions, it acts almost without exception depressingly. As an example I introduce a case of Kelsch and Kiener's:
Perez, aged twenty six, has lived at La Calle (Algeria) one year; breaks stone on the streets of Bona.
Admitted to the hospital December 15, 1874. He contracted fever for the first time three months before, and from September 21 to 27 was under hospital treatment.
Since then he has had several paroxysms, following one another irregularly. During the last fourteen days these have increased in frequency.
On admission no fever and nothing striking in his mental condition. He came on foot. Skin yellow; spleen enlarged.
December 16: During the day a violent paroxysm (40.5° C.-104.9° F.), unaccompanied by a chill. At the evening visit the expression of his face lively, the lips trembling. The patient was talkative and begged that he be cured. He spoke of his misery, while tears coursed down his cheeks. A few moments later he rose suddenly and sprang to the window in order to leave the hospital. Toward evening he became quiet, yet during the whole night he was troubled with dreams and visions.
December 17: The temperature fell under a copious sweat: morning, 38° C. (100.4° F.); evening, 37.2° C. (99° F.). His mind is clear; he is conscious of the mental disturbance that he manifested yesterday. Great prostration, sadness, slow intellection. He denies the misuse of alcohol, in that he refers to his poverty and his sobriety. He assures us that he has had no mental disease.
December 18: Temperature, morning, 38° C. (100.4° F.); evening, 37.3° C. (99.1° F.). Like the preceding, this night was disturbed by visions. He saw the Holy Ghost, found himself transported home, saw his relatives at his bedside. In the morning, gloomy thoughts, wished to die, spoke but little.
December 19: Temperature movement slight: morning, 38° C. (100.4° F.); evening, 36.8° C. (98.2° F.). The same mental condition as yesterday. From this day on, hypothermia.
December 28: The patient wishes to leave the hospital. Although his answers and behavior are reasonable, his mental condition is not normal. His thoughts are full of visions. He thinks he sees a carriage carrying him away. He is sad and reserved.