RESUMEN
This study was conducted on thirty children with grand mal epilepsy attending the paediatric neurology clinic of the Alexandria University Hospital for Sick Children, all of them were new untreated cases. The diagnosis was built up on both clinical and electroencephalographic grounds. Children were divided into two major groups; the first group received CBZ as the sole drug of therapy, the second group received sodium vaiproate as the sole antiepileptic drug. Serum and urinary sodium, potassium, osmolality, serum aldosterone and plasma ADH were determined for all the cases before initiation of therapy and three months later. Twenty normal age matched children without personal or family history of epilepsy or febrile convulsions were included in this study as controls and subjected to the same laboratory investigations