Infectious Psychoses

INFECTIOUS PSYCHOSES, mental disorders on the basis of infectious diseases. Chronic infections, especially when they directly affect brain tissue (for example syphilis), cause psychoses so characteristic of each infection that the latter require special description. On the contrary, psychoses associated with acute infections are generally not specific; they proceed according to the type of so-called exogenous reactions (Bonhoeffer), which are very similar to each other despite the difference in the infectious diseases causing them. In the course of acute reactions, the specific properties of the pathogenic agent are obscured; thus, encephalitis (see), developing in connection with acute infections, cause rapid damage to brain tissue, and the clinical and anatomical picture depends little on which agent caused the destruction. The known independence of acute psychoses from the type of the main infectious disease is however not absolute and does not exclude the presence of certain features in different infections (see below). In the pathogenesis of acute I. p., hereditary predisposition also plays a significant role, as well as acquired "disability" of the brain on the basis of various previously suffered diseases. The external manifestations of acute I. p. depend mainly on whether the infection has direct brain localization or whether the brain is only involved in the disease in connection with the circulation of toxins in the blood and exhaustion of the nervous system. I. Psychoses on the basis of acute infections without direct brain localization. These include: 1. Symptomatic psychoses. The most common form is feverish delirium, developing at the height of the infection and depending on the action of toxins and increased temperature. Hallucinations, delirium, clouded consciousness, disorientation in the surroundings, motor agitation, insomnia - the main symptoms of the disease, which ends with the fall in temperature. This form is distinguished from the so-called infectious delirium, which can develop at the very beginning of the infection, before the temperature rise, under the influence of toxins; the disease is manifested by severe clouding of consciousness, general weakness, headaches, disturbance of consciousness and agitation. In other cases, infectious delirium develops after the temperature drop; this is the so-called collapse delirium; finally, sometimes feverish delirium after the temperature drop does not end, but passes into the so-called residual delirium. All these varieties of symptomatic psychoses are short-term and end favorably; clinically and anatomically they are close to each other. Pathologically, insignificant changes capable of recovery are found in the form of cloudy swelling of nerve cells, tigrolysis, etc. Symptomatic psychoses themselves do not require treatment; they usually occur in somatic diseases; only intensified supervision of such patients is necessary, while the main therapy should be directed at the infection itself. 2. Post-infectious psychoses differ in greater duration, develop after the infection has ended and are a consequence of exhaustion of the nervous system and the entire organism in the absence of direct gross damage to brain tissue. Two main forms are distinguished: a) Acute confusion (amnesia) - is characterized by clouding of consciousness, delirium, hallucinations, illusions, motor agitation. Patients sleep poorly, are restless, confused, perceive their surroundings unclearly, strive somewhere, talk a lot and incoherently, etc. They do not recognize those around them, the mood is often elevated, sometimes there are attacks of fear, anger, anxiety. In individual cases, manic features or depressive features predominate in the clinical picture; there are also forms resembling stupor or the twilight state of epileptics; epileptiform states of excitement (Bonhoeffer) with severe disturbance of consciousness, fear, religious ecstasy and strong senseless excitement are quite characteristic. Finally, hallucinations are sometimes observed with relatively clear consciousness! The diversity of external manifestations gives grounds to divide amnesia into a number of forms, which however are not sufficiently delimited from each other; usually in the same patient there is a change of different clinical pictures. The disease usually lasts 2-3 months, recovery occurs more or less gradually. Memory of the disease is in most cases insufficient. The prognosis is favorable; the usual outcome is complete recovery, but death from exhaustion is possible. b) Post-infective mental weakness is a consequence of inhibition of mental functions, in contrast to the excitement characteristic of amnesia. The relationship between the two forms is undeniable, as there are transitional cases. In states of post-infective weakness, there is a disturbance of functions not only of the brain but of the entire organism (decrease in the vital activity of tissues and organs, damage to the autonomic nervous system); patients are exhausted, weak, lethargic, apathetic, sleep and appetite are disturbed, fatigue is sharply expressed, attention is extremely unstable, memory is weakened, patients seem to have lost their knowledge and skills, think poorly and with difficulty, are irritable; there are attacks of fear. The mood is usually depressed, orientation is unclear. Episodically - hallucinations and delusional ideas, mostly of unpleasant content. In more severe cases, patients are immobile, helpless, untidy. The disease lasts for several months and usually ends with gradual recovery. The prognosis however requires caution, as death from exhaustion and transition to dementia are possible. Pathologically, in both forms of post-infectious psychosis, acute changes in nerve cells are observed, usually transient, which corresponds to the favorable outcome of the disease. However, in post-infective weakness, these changes are more pronounced than in amnesia. The recognition of both forms of post-infectious psychosis is based on establishing the dependence of the disease on exhaustion after infection and on the absence of persistent signs characteristic of endogenous psychoses (especially schizophrenia and manic-depressive psychosis), the attacks of which can develop after infection, as after other debilitating moments of the body. Treatment consists of caring for the somatic condition, improving nutrition, etc. Rest, bed rest, baths are necessary. After recovery, a long rest is indicated. II. Acute psychoses with direct localization of infectious lesions in the brain are characterized not only by a more severe general reaction but usually also by local symptoms associated with damage to a particular area of the brain. These forms occur with elevated temperature, which depends on the brain damage itself (see Meningitis, Encephalitis). III. Chronic consequences of acute infectious psychoses are a consequence of persistent changes in brain tissue and can manifest in various forms. 1. Post-infective dementia without focal symptoms - a consequence of diffuse loss of nerve elements - is expressed by general apathy, inability to work, forgetfulness; these cases however do not give a progressive course and gradually improve (difference from schizophrenia). 2. Post-infective Korsakoff's (amnestic) syndrome occurs in elderly people and is a consequence of the insufficient ability of brain tissue to recover; it is manifested by characteristic memory disorders, confabulations, and general weakening of the psyche. The course is chronic, with a tendency to gradual improvement. 3. Changes in character are more characteristic of young age and are expressed in irritability, spitefulness, tendency to antisocial behavior (a state resembling psychopathy). 4. Meningitis, encephalitis and abscesses give local changes, the remnants of which are the cause of persistent paralysis, aphasia, apraxia, seizures, etc. As a result of infectious brain damage in early childhood, intellectual development in particular is delayed (post-infective oligophrenias). IV. Features of psychoses in various acute infections. Typhoid fever is often accompanied by psychoses: feverish and infectious delirium are common, as well as collapse delirium; post-infectious psychoses, amnestic syndrome, persistent states of dementia often develop. In typhus, feverish delirium is characterized by complex experiences with bright hallucinations; post-infectious psychoses are common. In typhus, direct damage to the brain in the form of scattered encephalitic foci in the cortex and brainstem is common; these lesions are sometimes the cause of resulting dementia in more severe cases. In relapsing fever, feverish and collapse delirium are common, sometimes meningitis; encephalitis are rare. Persistent manifestations of dementia are not common. In pneumonia, acute psychoses are common (violent feverish delirium, in alcoholics with the character of delirium tremens, collapse delirium, amnesia, etc.). Chronic sequential changes are rarely observed. In erysipelas, violent feverish delirium and delirium tremens in alcoholics are also common; an amnestic syndrome has been observed. In smallpox, epileptiform excitement states and very long-lasting amnesias are common; meningitis and encephalitis with subsequent persistent changes are also observed.

In acute articular rheumatism, there is observed a stormy feverish delirium with epileptiform excitement and convulsions during life-threatening hyperpyrexia; meningitis also occurs as well as amnesia with stuporous symptoms. In scarlet fever, feverish delirium is common, as well as meningo-encephalitis (sometimes in connection with ear disease) with subsequent persistent phenomena, uremia in connection with nephritis. In measles, psychoses are rarer and resemble those of scarlet fever. In diphtheria, infectious delirium develops infrequently; there are gross brain lesions (meningitis, abscesses). In whooping cough, psychoses are rare; convulsions and disorders of consciousness have been observed in connection with coughing fits, as well as (very rarely) meningo-encephalitis. Influenza is characterized by the fact that during it feverish delirium is rare and post-infectious psychoses are common, as well as severe encephalitis (especially in children) with subsequent persistent changes. In dysentery, psychoses are rare; nevertheless, states of mental weakness and even amnestic syndrome have been observed. Psychoses are also rare in cholera; delirium of collapse, stuporous and manic amnesia, and amnestic syndrome have been observed. In plague, drowsiness and sharp states of excitement with fear and impulsive actions have been described. In pyemia and septicemia, infectious and post-infectious psychoses are not uncommon; abscesses in the brain may develop. In malaria, psychoses occur in the form of epileptiform states of excitement, amnesia, amnestic syndrome, and persistent dementia on the basis of meningo-encephalitis. I. p. are also possible during exacerbations of the tuberculous process (especially in tuberculous pneumonia); hallucinosis, amnesia, and amnestic syndrome have been described; meningitis also occurs. Acute and subacute infections with selective brain localization and a specific picture of the disease (lyssa, chorea minor, etc.) stand apart and require separate description. Statistics on the incidence of psychoses in different infections are very insufficient, contradictory, and depend on the characteristics of individual epidemics. In typhoid fever, different authors indicate from 1.5% to 38% incidence of psychoses, in erysipelas-7-9%, in articular rheumatism-1.7-12.3%, in lobar pneumonia-up to 20%. For other infections, the data are even less definite or completely absent.