[Dynamics of the premorbid nervous system defect in children with acute infections and craniocerebral injuries].

Owing to a high plasticity of the child's brain complete or partial compensation of a cerebral defect is possible. However an infection or a craniocerebral injury may interfere with the compensation of the premorbid defect of the nervous system: this was noted in 65% of children observed by the authors. Therefore, while specifying the syndromological structure of a disease one must take into account the time course of the premorbid defect. The compensation of that defect is hampered most often in children of the first year of the life. In these cases a loss of a part of acquired habits and appearance of earlier-age reflexes is noted. At the age of 2 to 5 years an aggravation of the atactic and hyperkinetic syndromes is observed, while at the age of over 5 years the negative time course of the premorbid defects is noted twice as rarer. Variants of the time course of the premorbid nervous disorders are specified. At the basis of reversible variants are disturbances on the part of hemodynamics and cerebrospinal fluid. This is confirmed by echo-EEG and REG findings. Persisting aggravation of the premorbid defect and appearance of new neurological symptoms are observed on development of hypoxic and metabolic disturbances. The nervous structures affected by perinatal hypoxia remain thenceforth to be especially sensitive to the effects of the latter. An analysis of the pathogenetic mechanisms of the premorbid defect decompensation may facilitate the realization of therapeutic and prophylactic measures.