Mental disturbances of various types associated with somatic conditions and not sufficiently characteristic or circumscribed in their symptomatology to constitute definite and separate psychoses have long been recognized. That delirium is a complicating factor in certain acute febrile diseases has been known for centuries. Aristotle called attention to the occurrence of hallucinations and illusions during the course of fevers. Hippocrates referred frequently, not only to excitements, but to delirium and phrenitis. The word "delirus" appears in several places in the works of Horace and many of the early authors apparently used this term as synonymous with both mania and melancholia. That was probably true of Sennert. Flemming in 1844 mentioned fever delirium, hallucinatory and delusional clouded states and an encephalitic form in addition to the various alcoholic types. Sydenham referred to the mental symptoms associated with malaria and Bright in his original "Reports" described other delirious conditions at some length. Sir Thomas Watson showed that the brain was uninvolved at autopsy in the acute rheumatic affections with apparent cerebral complications. Mental symptoms have, of course, been associated for hundreds of years with meningitic processes. Diabetic coma was also recognized long since. Griesinger is said by some to have been the first to call attention to the psychoses caused by the acute infections. Post febrile mental disturbances were, however, referred to by Sydenham, Baillarger, Westphal, Greenfield, Gubler and many others. Delasiauve very elaborately described the psychoses associated with typhoid fever in 1849. The mental disorders accompanying gout were discussed at considerable length by Sydenham and were referred to as early as 1699 by Philander Misaurus.
According to Bucknill and Tuke[261], Misaurus made the following very interesting suggestions in an article entitled "The Honour of the Gout": "It would be worth inquiry, whether the gout is not as effectual against madness; and we may reasonably believe that it is so, if upon examination, it should be found that there are no gouty people in Bedlam; and then for the recovery of these poor creatures to their wits again, it will not need much consideration, whether they ought not to be excused the hard blows which their barbarous keepers deal them, and the Therapeutic method of Purging, Bleeding, Cupping, Fluxing, Vomiting, Clystering, Juleps, Apozemes, Powders, Confections, Epithemes, Cataplasms, with which the more barbarous Doctors torment them, and instead of their learned Torture, indulged for a time only, a little intemperance as to wine, or women, or so; or the scholar's delight of feeding worthily, and sleeping heartily, whereby they might get the Gout, and then their madness were cured." Clouston described a very definite form of phthisical insanity. Van der Kolk made the surprising statement that phthisis and mania often alternated in regular cycles. Nasse classified the mental conditions associated with fevers as either resulting directly from the febrile disturbance, constituting a prolongation of the delirium after the temperature subsided, or developing during convalescence.
The German psychiatrists during the first part of the nineteenth century were divided into two quite separate groups. One of these insisted that all mental diseases were purely psychic in origin, and the other, that they were in all instances directly attributable to somatic disease processes. The former school was ably represented by Heinroth and Ideler and the latter by Jacobi, Nasse and Friedreich. This led to a controversy which lasted for many years. Heinroth's views were illustrated by his statement[262] that "Insanity is the loss of moral liberty. It never depends upon a physical cause; it is not a disease of the body but of the mind—a sin.... The man who has during his whole life before his eyes and in his heart the image of God, has no reason to fear that he will ever lose his reason.... Man possesses a certain moral power which cannot be conquered by any physical power, and which only falls under the weight of his own faults.... From wrong doing springs all misfortune, including the disorders of the mind." His principal work was a "Lehrbuch der Seelenkunde," published in Leipsic in 1818. The teachings of the psychic school were summarized by von Feuchtersleben[263] as follows:—"The mind is the immediate seat of the disease, the bodily suffering is secondary. Mental disorders may be clearly traced to their origin, Sin, Error, Passion. Diseases of the brain, on the contrary, and of all the organs, occur, even in their greatest intensity, without mental disturbance, as also the latter without the former. The psychical mode of cure is that which is properly efficient; the somatic remedies in reality act psychically; for instance through pain, diversion of the thoughts, stupefaction, terror. Pathological anatomy has not discovered any decided relation between disorganization of the brain and mental disorders." In 1836 Friedreich[264] in opposing Heinroth's views outlined thirteen reasons for believing that all psychic disorders were somatic in origin:—"1. Because the mind cannot become diseased; 2. because the greater part of the causes producing those conditions is somatic; 3. because in all mental disorders there are somatic symptoms in addition; 4. because they are too permanent for pure conditions of the mind; 5. because they are subject to cosmical and telluric states; 6. because their crises always take place in a material way; 7. because they are not infrequently removed by strong material influences; 8. because the somatic mode of cure alone has a direct sanatory effect, the psychical at most an indirect effect on the body; 9. because the occurrence of psychical indisposition on one side only, must arise from the duality of the brain; 10. because the return of reason before death occurs in cases not only of psychical, but likewise of somatic diseases, and may be physically accounted for; 11. because mental disorders correspond with the temperaments; 12. because it may be proved that there are psychical conditions which depend on organic causes, and are therefore very analogous to psychical disorders; 13. because chronic delirium (mania) can be no other than febrile." Absurd as such discussions may seem at this time, they are no worse than the theological debates of that day. As a matter of fact, they were no more futile than the efforts still being made to classify the various psychoses on some one common ground, for any other than purely statistical purposes.
Kraepelin[265] divides the psychoses due to infection into febrile delirium, infection delirium, acute confusional states (amentia) and exhaustions. The result of the infectious process, as he says, may be merely to precipitate a manic-depressive psychosis, or an attack of dementia praecox, general paresis or delirium tremens. It may also be manifested in the form of a neuritis, myelitis, encephalitis, or a meningitis. Bonhöffer in 1910 described several forms of "symptomatic psychoses" due to infections and divided them into three main groups: deliria, confusions and mental enfeeblements. He also referred to epileptiform excitements, dream states, hallucinoses, manic types and amentias either hallucinatory, catatonic or incoherent in character.
Kraepelin speaks of several definite stages or forms of febrile delirium. In the mildest of these there is a feeling of discomfort with a sensation of fulness in the head and a marked sensitiveness to external impressions. In the second stage a suggestion of clouding becomes apparent and perception is distorted by hallucinations and illusions. There is an increased activity of the mental processes and consciousness soon assumes a dreamlike form. Hallucinations and illusions are mixed with realities. The restlessness increases and excitements or depressive moods may precede the appearance of the third stage. In this there is a more pronounced disturbance of consciousness with disorientation, confusion, flight of ideas, and variable emotional reactions, sometimes with actual manic manifestations. Evidences of stuporous tendencies may appear at times. In the fourth stage a state of weakness develops, with picking at the bed clothes, tremulous movements and a senseless muttering of words and syllables. This terminates in complete coma. In smallpox, scarlet fever, erysipelas, articular rheumatism and pneumonia there are often sudden confused excited states, while in typhoid fever stuporous delirium is the rule. Hendriks found the mental symptoms in typhoid greater during convalescence and not closely related to the febrile reaction. He describes a marked disturbance of attention with little involvement of apprehension or comprehension, but marked loss of mental capacity and sometimes a tendency to confabulation. Visual hallucinations and loss of sleep are common symptoms. Often there is restlessness, talkativeness, indifference, carelessness and disturbances of volition. In articular rheumatism and scarlet fever, according to Kraepelin, delirium sometimes develops with sudden rise of temperature. Restlessness, talking in the sleep, volubility or dulness precede an unusually violent delirium, sometimes terminating in stupor and death. The basis of these conditions in all cases is the toxic infection causing the fever, changes in metabolism, circulatory disturbances and an involvement of various organs, particularly the brain. A rapid and considerable rise of temperature usually causes delirium in typhoid, smallpox and erysipelas while it has no such effect usually in tuberculosis. This disturbance is a direct result of the influence of the toxins on the cortex. Alcoholism constitutes another well-known and common cause. In seventy per cent of the cases the duration was less than one week and the delirium disappeared with the fall in temperature. Some cases terminate in infection delirium or they may precipitate genuine attacks of manic-depressive insanity, dementia praecox or general paresis.
The so-called acute alteration of Nissl was a very common change found in the cortical cells at autopsy. This very generally involved the entire cortex. Kraepelin describes another characteristic alteration observed in cases of typhoid delirium. The Nissl bodies are clumped together in the periphery, and are deeply stained, the processes also being unusually dark. Some cells show a shrunken nucleus with swollen, lightly stained bodies. Around these neurones there are usually large accumulations of elongated glia cells.
In the infection delirium, so called, the mental disturbance develops in a case where there is no hyperpyrexia or where at least there is no relation between the psychosis and the temperature. A restless excitement ushers in the attack. Pressure in the head, mental dulness, depressed or sometimes cheerful moods, uneasiness, disturbed sleep and anxious dreams are common symptoms. Later a disturbance of consciousness appears and a special type known as "initial delirium" may develop. This is a common occurrence in typhoid fever.
Aschaffenburg described two forms of initial delirium. The first is a restless condition of clouding with hallucinations and delusions. The second form, which may develop from the first, shows active mental excitement. Mild in its onset, a confusional delirious state soon develops with flight of ideas, hallucinations, delusions, and marked anxiety. An initial delirium of this type often occurs in smallpox. This assumes a particularly severe form with a tendency to suicide and violence, strongly resembling epileptic dream states. Seizures and epileptiform convulsions may occur. The delirium usually develops from the third to the fifth day of the disease and mental enfeeblement sometimes follows. The attack usually lasts from several days to a week. It may continue as a fever delirium. About forty or fifty per cent die. Nissl in one case found a marked congestion of the vessels of the cortex, with an increase in the number of leucocytes, and a widespread destruction of the neurones. The cell bodies were swollen and the chromatin lumps destroyed. Karyokinetic changes were noted in the glia cells.
More or less similar delirious states occur in the course of intermittent malarial fevers. These usually take the form of a marked anxious excitement, often with stupor or a tendency to violence. The attacks begin suddenly, last only a few hours and end in sleep. Convulsions are frequently observed. These conditions occur in the quotidian or tertian types but rarely in the quartan. The delirium precedes a febrile disturbance or may take its place. It is apparently due to an accumulation of plasmodia in the cerebral vessels. In influenza, restlessness, confusion, anxious excitement or hallucinatory deliria may be associated with a low temperature. Polyneuritic manifestations have also been observed. The disturbance is undoubtedly caused by the influenza bacillus or the action of its toxins on the cortex. Abscesses are found in some instances. Deliria with phthisis are rare unless there is a tubercular meningitis. In the septic infections, conditions with marked clouding are often observed, and are to be attributed to embolism, metastases, etc. Muscular weakness, aphasia, perseveration and convulsions may be present in these cases. Infection delirium also occurs in chorea. This takes the form of a clouded dreamlike state with confusion of thought at times, hallucinations, delusions, and emotional excitement accompanied by characteristic choreiform movements. Apprehension, as a rule, is unimpaired, but attention is disturbed and the patients are forgetful and distractible. They do not have a clear grasp on their surroundings. Occasional hallucinations appear. The mood is anxious, excited, fearful or irritable, sometimes with outbursts of anger or threats of suicide. The choreiform attacks are aggravated and speech is affected. The reflexes are decreased and muscular weakness develops. The pupils are dilated and sleep is interfered with to a marked degree. This excitement lasts for a short time only, but often recurs. In nine per cent of the cases (Kleist) death results from heart failure, septic infection or other intercurrent diseases. Wassermann and Westphal demonstrated streptococci in the brain in several cases of chorea. Others have reported staphylococci in the blood. Choreic delirium is usually associated with endocarditis or rheumatic infections, and occurs in the acute type but not in the Huntington variety of the disease.
Delirious excitements, according to Kraepelin, also occur in acute cerebrospinal inflammatory processes and may be due to furunculosis or caused by infections from the mouth or the intestinal tract. There is nothing particularly characteristic in such conditions aside from their severity. They have been collectively described under the designation of "acute delirium." Their differentiation depends entirely on the demonstration of the source of infection. The anatomical basis for these disturbances is always found in the cerebral cortex. The pia is infiltrated with lymphocytes and plasma cells and leucocytes are found in the perivascular spaces. There is also a proliferation of the glia. The "grave" alteration of Nissl is often demonstrable. After the infectious process passes its maximum intensity and the delirium disappears, "residual" delusions may remain with a clear sensorium. These may last for several days or even weeks. They frequently follow typhoid fever. Occasionally hallucinations of sight and hearing persist in the same way.