BACKGROUND: This article reports the results of research into the activitiesof lactic acid concentrations in the body fluids of children with progressive encephalopathies (PE) incomparison to patients with non-progressive encephalopathies (NPE) and those with non-progressive encephalopathieswith concomitant epilepsy (NPEE). The study was designed to determine whether there is difference betweenthe serum and CSF lactic acid concentrations in children with progressive encephalopathies (PE), static(non-progressive) encephalopathies (NPE) and non progressive encephalopathies with concomitant epilepsy(NPEE), and whether the clinical status correlates with the concentration of these biochemical markersin children with PE. MATERIAL/METHODS: The assessment involved 138 children of both sexes, whose ageranged between 8 months and 15 years, diagnosed and treated in the Neurology Department at the PediatricClinic of the Silesian Medical Academy in Katowice between 1995 and 1997. Lactate concentrations weredetermined in serum and cerebro-spinal fluid and analyzed statistically. RESULTS: The findings showedhigher serum and CSF concentrations in children with PE than in patients who manifested non-progressiveforms of encephalopathy. The degree of clinical symptom aggravation in PE children was likewise analyzedand compared to the values of lactate concentrations in body fluids; however, no correlation was foundbetween these parameters. CONCLUSIONS: Children with progressive encephalopathies present higher lactateconcentrations in serum and cerebrospinal fluid than patients with static (non-progressive) encephalopathy.

Keywords: Adolescent, Brain Diseases, Case-Control Studies, Cerebrovascular Disorders, Child, Child, Preschool, Epilepsy, Lactic Acid