Disease as a Way of Life: Neural Integration in Systemic Pathology

DISEASE AS A WAY OF LIFE: NEURAL INTEGRATION IN SYSTEMIC PATHOLOGY STEWART WOLF, M.D.* I.Man and His Brain Presumably the high development of the mammalian nervous system has been responsible for the continued presence ofour class in the world. The dinosaurs had far more formidable weapons of attack and defense than the mammals have, and yet they became extinct at about the time the mammalian design was developed in the course ofevolution. Mammals are generally more vulnerable than reptiles, but they are also more adaptable. The integrative activity of their brains provides for maintaining the temperature ofthe blood more or less constant in the face of a variation of ioo degrees or more in the surrounding atmosphere. Also, mammals are able to adapt to wetness and dryness, to altitude, and to the wily predatory maneuvers of their enemies. It would appear, therefore , that the purpose ofthe brain may be not so much to maintain constancy ofinternal environment but rather to permit effective adaptations to changes in the external environment. II.The Nature ofDisease The long controversy that raged a century ago about whether diseases were "entities" or fundamentally normal bodily functions gone wrong has no real meaning today. Physicians now consider most diseases to be distinct from one another insofar as they represent patterned responses or adaptations to noxious forces in the environment. They are thus both ''normal''bodilyfunctionsinthesensethattheyareadaptivephenomenaand * Department of Medicine, The University of Oklahoma Medical Center, Oklahoma City 4, Oklahoma. This paper was presented as the Minot Lecture to the Section on Internal Medicine ofthe American Medical Association, Atlantic City, June 9, 1959. 288 Stewart Wolf · Disease as a Way ofLife Perspectives in Biology and Medicine · Spring 1961 "entities" to the degree that they are classifiable and separable, one from the other, on the basis ofeither causativefactors or similarity ofmanifestations . Phenomena generally recognized as indications of disease include quantitative alterations in body temperature, arterial pressure, the formed elements ofthe blood, vasomotor activity and hemodynamic mechanisms, the secretory activity of glands, and certain biosynthetic functions like, for example, those which characterize the sequence ofblood coagulation. Other manifestations ofdisease include vomiting, malaise, and headache and other pain; muscular weakness, alterations in mood and behavior, and loss of consciousness; alterations in amount and composition of blood, plasma, and excretory products; shifts in electrolyte concentration in various body compartments; immunological phenomena involving alterations in capillary permeability; excessive cell reproduction; and tissue changes such as hyperemia, edema, and necrosis. A great variety ofdiseases share these mechanisms and manifestations in diffèrent combinations. Many ofthese mechanisms, the manifestations ofdisease, have been shown to be subject to influence or control by the central nervous system acting through neural, vascular, or endocrine pathways (1-4). Traditionally, physicians have been inclined to consider diseases more localized than they really are, often on the spurious assumption that they involve only a single organ or organ system. Thus, pneumonia is thought ofas a disease ofthe lungs although many ofitsmanifestations—including fever, leukocytosis, increased antibody titers, tachycardia, etc.—are brought about by changes in organs distant from the lungs, such as the brain, the bone marrow, the lymph nodes, and the heart. The widespread manifestations ofdisease are usually nicely patterned. In congestive heart failure, for example, delicately balanced chemical, circulatory, and renal adjustments are well known as well as several alterations in endocrine secretions , including antidiuretic hormone, aldosterone, thyroid hormone, and corticosteroids. Again, many ofthese mechanisms have been shown to be connected with the central nervous system. Neural integration is a complex system involving receptor and effector activity and something connecting the two. The connection may be direct , as in a simple reflex arc, or roundabout through interposed fibers concerned with interpretation, association with learned experiences, and other neural impressions either on a conscious or unconscious level. Thus, neural integrative activity refers to what takes place between the delivery 289 of an afferent impulse to the central nervous system and the formation of an efferent pattern of response. It may occur at several levels of the nervous system. When language or other types ofsymbolism are involved, the process must include the highest integrative level, the cerebral cortex. Thus the ultimate effector pattern may often depend upon the peculiar...