Clouding of Consciousness

CLOUDING OF CONSCIOUSNESS, a disturbance of psychic functions, characterized mainly by a disorder of perception and processing of impressions and usually leading to disorientation. Clouding of consciousness accompanies very many diseases, both cerebral and of the entire organism, whereby it is a symptom indicating to some degree the relative severity of the disease. At the basis of clouding of consciousness may lie, on one hand, inflammatory processes in the brain, various kinds of disorders of cerebral circulation, changes in intracranial pressure, and finally direct violations of the integrity of brain tissue; and on the other hand, it may depend on the toxic effect on the brain of pathologically altered blood flowing through its vessels (in cases of this kind, the disturbance of the so-called blood-brain barrier apparently plays a prominent role). Clouding of consciousness can also be of functional origin as a consequence of psychic shocks and affective experiences of excessive intensity. The simplest form of clouding of consciousness is the unconscious state, i.e., the complete annihilation for a known period of time of both visible psychic manifestations and subjective experiences, developing as a result of either traumatic injuries or sharp changes in the conditions of cerebral circulation (concussions and contusions of the brain, cerebral hemorrhages, spasms of cerebral vessels, disorders of general circulation causing anemia of the brain, etc.). With a lesser strength of the harmful factor or with its slower action, a state of stupor develops, characterized by general lethargy, lack of clarity of perceptions, slowing of intellectual processes, emotional indifference, and confusion (in brain tumors, after strokes upon the passing of the unconscious state, after traumas, etc.). One of the most frequent forms of clouding of consciousness consists of states accompanying febrile and infectious diseases, as well as various intoxications and autointoxications (diabetic coma, uremia, etc.). In these cases, the psychic picture is composed of a combination of phenomena of psychic weakness and excitation: inability to fix impressions, incoherence of thinking, and more or less pronounced delirious phenomena, which in severe cases come to the fore. With especially strong intoxications, excitation is often replaced by depression with an almost complete cessation of signs of psychic activity. Such—comatose—states are often immediate precursors of death. Coma represents the extreme degree of stupor. Some distinguish from it, under the name of sopor (or torpor), such states when the patient voluntarily almost does not react to what is happening around him, but by strong irritation can be provoked for a short time to a conscious reaction. Regarding other forms of disturbance of consciousness, see Consciousness.