Neurokynurenines--seizures or/and anxiety in children with epilepsy?

Neurokynurenines (NK) possessing various neuroactivities, are involved in many abnormalities in stress, anxiety, depression, alcoholism, epilepsy, neurologic diseases. Level of the excitatory NK, e.g. kynurenine (KYN) and quinolinic acid (QUIN), is elevated in many of those diseases, and a correlation between a rise of NK and severity of symptoms has been registered. In some of those diseases a rise of the level of the inhibitory NK, e.g. kynurenic (KYNA) and xanthurenic (XAN) acids, has been observed as well. However, that rise was smaller than that of the excitatory NK. Those changes are resulted in a shift of the balance between the excitatory and the inhibitory NK towards prevalence of the formers. Just a ratio between them determines a final integrative functional (or clinical) effect. Actually, a rise of the level of the excitatory and inhibitory NK is not specific for any disorder ( the same is true for catecholamines, serotonin, neuropeptides etc). To differentiate a relative role of NK in a neurological disorder it is important to check symptoms of stress and anxiety and their severity together with symptoms of a disease and their dynamics. This seems to be promising for understanding whether any shifts in concentrations of NK, e.g. KYN, QUIN, XAN or KYNA, are related to symptoms of a disorder or severity of accompanying stress and anxiety. As a pilot trial, 30 children (4-14 years old) with epileptic seizures were studied. Excretion of XAN (as a putative anticonvulsant) was measured in 24-h urine samples and concentration of XAN in blood serum on admission to the hospital after a seizure-episode and before discharge after treatment. Symptoms of anxiety were rated. We found that while the levels of XAN are normalized at achieving a clinical remission (seizures), symptoms of anxiety and stress are increased. Our preliminary results suggest that that XAN is involved in the formation of late psychic pathology in children with epilepsy.