ADA and Hydrocephalus: Therefore, for hydrocephalus patients with no fever, negative meningeal stimulation, and a negative CSF bacterial culture, if only CSF leucocyte, chloride, aspartate aminotransferase, lactate dehydrogenase, adenosine deaminase and protein levels are abnormal, the ventriculoperitoneal shunt should be performed as early as possible, as avoiding external drainage increases the risk of infection and delays the timing of shunt surgery.