Functional Diagnosis

FUNCTIONAL DIAGNOSIS, a branch of diagnostics having as its task the establishment of disruptions in the functions of organs and systems. F.d. cannot and should not replace semiology, i.e., the description of clinical symptoms of disease. F.d. to an even lesser extent concerns purely anatomical details of diagnosis, i.e., the establishment of the nature of the lesion (e.g., whether there is cystic degeneration or tuberculosis of the kidneys?). From a pathophysiological point of view, only F.d. can give a correct understanding of the degree of organ damage and its loss of functional capacity. In other words, only functional diagnostic methods, if they are accurate, ensure obtaining information about the adequacy or inadequacy of the functions of organs and systems of the body. It is quite obvious that the application of F.d. is often even significantly more important than the identification of an anatomical diagnosis, since with its help the prognosis of the disease, its further course and outcome are outlined. F.d. also has considerable influence on the treatment of diseases, predetermining both the nature of therapy and the limits of its permissibility. F.d. of organs is developed on the basis of existing physiological concepts about the activity of these organs. The methods used to establish a functional diagnosis are very different. In some cases, the composition of biological fluids of the human body (urine, blood, gastric juice, saliva) is studied and compared with normal data. For F.d. of other organs, electrical phenomena in them (heart, muscles), refractive properties (eye), or finally their energy influence (basal metabolism for the thyroid gland) are studied. More precise information about the performance capacity of organs can be obtained after imposing certain functional requirements on them. Thus, for example, the limits of adaptation of the activity of the kidneys or liver are determined by means of various artificial loads. The most accurate diagnostic data are obtained in cases where loads of substances are used that serve as physiological irritants for a given organ, such as sugar for the liver, water and table salt for the kidneys, measured work for the heart. The introduction of various foreign substances into the body (dyes for parenchymatous organs, indifferent gases for the study of blood circulation and respiration) has also become widespread. F.d. often also makes it possible to identify damage to individual partial functions of an organ, for example, the glycolytic function of the liver, erythropoiesis, nitrogen excretion in the kidneys. Interpretation of F.d. data often presents great difficulties, since it is impossible to separate changes in organs from the influences of other systems and the body as a whole. (For more details on F.d. methods, see the relevant chapters on individual organs—Liver, Stomach, Heart, Pancreas.)

m. Vovsp. FUNCTIONAL PSYCHOSES. Under F.p. were understood psychoses in which, with the current state of knowledge, destruction of brain cells or systems cannot be found; it was implied that sooner or later the patho-anatomical substrate of the disease would still be found and F.p. are thus only a temporary, transitional group. The concept of F.p., as well as the concept of functional diseases in pathology in general, arose in the second half of the 19th century, in the era of the dominance of cellular pathology and patho-anatomical understanding of the etiology of diseases. The term functional psychoses was first used in the psychiatric classification by Schüle and Krafft-Ebing, and they, as should have been the case by the very essence of the definition of the term 'functional', divided all psychoses into organic and functional. Krafft-Ebing, in addition, divided the group of F.p. into: a) psychoneuroses—diseases affecting a previously healthy brain; he included melancholia, mania, stupiditas, dementia acuta curabilis and delirium hallucinatorium; b) mental degeneration diseases, which are the final link in the chain of neurotic peculiarities of the family, increasingly intensifying from generation to generation; Krafft-Ebing included paranoia, epileptic and hysterical insanities and periodic psychosis. Psychoneuroses, according to Krafft-Ebing, tend to end at a certain period of time or with recovery or dementia; in degenerative psychoses it is difficult to find boundaries where the psychosis begins, in them 'usually the most varied change of the most diverse psychotic states is observed, so that no pure, complete pictures of the disease are formed, but rather a mixture of various forms; the course of the disease is usually protracted, not passing at all or rarely passing into a state of complete dementia, a great tendency to periodicity'. According to Schüle, F.p. included not only all the above-mentioned F.p. of Krafft-Ebing, but also mental disorders due to various intoxications and infections. The relationship of these psychoses to functional ones was particularly vividly substantiated by Flexig, who pointed out that the difference in the reaction of different individuals to toxic harmfulness, e.g., alcohol, the speed with which these disorders develop, excludes the thought of the possibility of organic changes in the structure of nervous tissue in these cases. According to Flexig's opinion, it is most probable to assume here a temporary disorder of the chemical process or metabolism, which, in his opinion, constitutes one of the forms of functional disorders of the nervous system. Thus we see that already Schüle, Flexig, Krafft-Ebing linked the origin of F.p. to the peculiarities of the entire personality. With the passage of time, the concept of functional and organic mental diseases became more and more precise. First of all, the concept of organic came to include not only secondary degenerations due to gross mechanical destruction of tissue, but also primary degenerations under the influence of pathophysiological effects (fluctuations in temperature, disorders of blood circulation, nutrition of nervous tissue, changes in blood composition, especially the introduction of toxic substances into the blood, including toxins due to incorrect metabolism, etc.), degenerations associated with congenital weakness of a given system (see Pathoarchitectureonics). Furthermore, the combination of purely functional disorders and organic disorders arising on the basis of functional disorders began to be noted; it had to be recognized that often a series of diseases of the nervous system—from the most subtle functional to the most gross anatomical processes—can be connected by a series of transitions, that not only anatomical destruction causes functional disorder, but functional disorder can lead to anatomical destruction. The reversibility of organic processes at a certain stage of their development was noted, which was particularly vividly expressed in the improvement, for example, after malaria treatment in progressive paralysis even of marked organic disorders. In addition, the violation of the function of an organ began to be connected not only with the violation of the morphological basis of this organ, but also with the complex structure of the entire organism. Many functions began to be conceived as possible only as components of the complex activity of the entire structure of the organism, and not of certain individual elements. All psychiatrists at the present time recognize the existence of such mental diseases in which not only are there no destructive changes, but they fundamentally cannot be found, and there are only peculiarities of the general structure, 'constitution' and interaction of the entire organism as a whole with the environment. Bumke points out that 'mental processes are not localized, but only certain mechanisms that the psyche uses for communication with the external world'. Even Wernicke formulated that mental disorders in progressive paralysis are the result of the entire complex of focal diseases of the cortex, and not determined by individual foci. The destruction of none of the centers is specific for mental illness. Even Kleist, one of the most prominent modern supporters of the importance of brain localization in psychiatry, points out that individual symptoms are localized, not the essence of the psychosis. Birnbaum correctly points out that 'psychosis is the product of the joint play of the pathological process and the reaction of the personality'. Therefore, in modern psychiatric classifications, a special group of 'functional psychoses' is no longer distinguished. The pathogenesis of each psychosis is connected with the entire structure of the personality as a whole, with its constitution, the peculiarities of its biological development in this environment and the peculiarities of its mental reactions to the surroundings. t. Yudin.