Alteration of amino acid in plasma and cerebrospinal fluid of children with seizure disorders.

Amino acid levels in plasma were measured by amino acid autoanalyser in 130 convulsive children. The levels of taurine, serine and tryptophan were significantly lower in convulsive children as compared to normal control; in contrast, isoleucine, homocystine, GABA, histidine, arginine and ammonia were higher. The children with paroxysmal disorders (headache, dizziness and abdominal epilepsy) had the highest levels of isoleucine, histidine and arginine and the lowest levels of glutamate and cystein. Clinical seizure activity within 6 months prior to the test seemed to have no obvious effect on the plasma amino acid pattern, except for the levels of glycine and arginine tended to return to normal, and the level of GABA was significantly increased in patients with the seizure being controlled. The patients treated with carbamazepin as a single anticonvulsant had the highest GABA level compared to those with other anticonvulsants. Hyperglycinemia and hyperammonaemia were also noted in patients who took valproic acid. The levels of serine, isoleucine and phenylalanine in the CSF within 6 hours after convulsion were significantly lower than the normal control; while asparagine, tyrosine, lysine and arginine were significantly higher. The concentration of ammonia in the CSF was also elevated after convulsion as compared to the normal control. Amino acids play an important role in the generation of epilepsy and recently there has been an increasing number of studies to help determine their effects during an epileptic attack. However, there still is much debate and controversy on this topic. Therefore, further studies are needed and researchers should carefully consider factors that might affect the accurate assessment of the results.