237 Csf-Lactate as a Marker of Mitochondrial Disorders Even in Children After Brief Seizures

Abstract

Background: An increased level of lactate in body fluids serves as a biochemical marker in assessing patients with inherited metabolic disease; especially in children with mitochondrial disorders that arise from isolated or combined defects of respiratory chain complexes and ATP-synthase. On the other hand increased lactate may be falsely considered to be the result of seizures in children with mitochondrial disorders. Therefore we ascertained the diagnostic value of lactate and alanine in blood and cerebrospinal fluid (CSF) in children with mitochondrial disorders (n=24), epilepsy (n=32) and psychomotor retardation (n=23).Results: Average blood and CSF lactate levels were significantly higher in children with mitochondrial disorders (3.87±0.48 and 4.43±0.55 mmol/l) than in children with epilepsy (1.72±0.13 and 1.62±0.04 mmol/l) or psychomotor retardation (1.79±1.40 and 1.68±0.06 mmol/l). Blood and CSF alanine levels were also significantly higher in children with mitochondrial disorders than in children with epilepsy or psychomotor retardation. The CSF lactate levels of children with epilepsy were similar whether the samples were obtained 3±0.6 hours after an attack of brief seizures or from children without history of recent seizures.Conclusion: Even in children who have recently suffered short-lasting seizures, elevated cerebrospinal fluid lactate level is a reliable marker pointing to the mitochondrial origin of disease. Brief seizures lasting less than 2 minutes do not increase lactate concentration in the CSF. Repeated lactate analyses are sometimes necessary, because lactate may be elevated only intermittently in children with mitochondrial disorders.Work was supported by grants IGA MZ NS 10561- 3/2009 and IGA NS 9782-4/2008