THE PREDICTIVE VALUE OF VENTRICULAR CSF REMOVAL IN NORMAL-PRESSURE HYDROCEPHALUS

We report the impact of diagnostic ventricular CSF removal (VCR) on th e gait disturbance in 24 patients with suspected normal pressure hydro cephalus (NPH) who had an intraventricular catheter for studies of CSF dynamics in order to select patients for shunt surgery. There were no complications related to removal of 24 mi CSF over a period of 6 hour s in four instances or to the removal of 15-18 mi at one time in twent y instances. Seventeen out of 24 patients were diagnosed as having NPH . Two of those patients who had relatively mild symptoms had a prolong ed amelioration of their gait disturbance after diagnostic VCR. Thirte en patients underwent subsequent shunt operations. Eleven of them had good functional and symptomatic improvement on follow-up. In those six patients who had a marked amelioration of their gait disturbance afte r diagnostic VCR, not only improvement of the gait disturbance was obs erved after shunting, but a consistent overall improvement as well. Th e predictive value of VCR was more variable in those six patients who had only a moderate response to VCR. No change of the gait disturbance after VCR was noted in seven patients in whom the diagnosis of NPH wa s not confirmed Diagnostic VCR might be a valuable ancillary test in s pecialized centers which routinely use intraventricular CSF monitoring in the selection of patients for shunt surgery.