CSF production rate: "real time" estimation.

CSF production rate has been measured by a drip detector method in 5 cases of childhood hydrocephalus undergoing closed ventricular drainage. The rate of production of CSF with this "real time" estimation is shown not to be constant but to be discontinuous and may vary by a factor of 10 over a one hour period, although the average rate of CSF production remains within previously established normal limits.