RESUMEN
This study was made on [100] hydrocephalic children aging from one month to eight years. These patients attended Neurosurgery Department of AI-Azhar University Hospitals and Neurosurgery Department of Nasser Institute Hospital, in the period from. November 1997 to November 1999. They were examined physically and radiologically, to exclude any hydrocephalic case associated with any other intracranial lesion. Serum and CSF samples were taken during ventriclo-peritoneal shunt operation for all patients and serum samples from all their mothers were collected and examined to detect anti-Toxoplasma IgG using indirect ELISA. Forty normal children serum samples and their mothers sera were examined for IgG as control. Positive anti-Toxoplasma IgG was detected in 23% which was significantly higher than control [P<0.01] with O.D. values significantly higher [P<0.01] of hydrocephalic children and their mothers denoting that their infection may be congenital from their mothers. The mean optical density [O.D.] of anti-Toxoplasma IgG antibodies in the cerebrospinal fluid of hydrocephalic cases was significantly higher than their level in the serum of the same patients [P<0.001]. This means that there may be local antibody production in the CNS. Congenital infection with T. gondii might be a cause of congenital hydrocephalus in Egypt