Correlation of ventricular size and transcranial Doppler findings before and after ventricular peritoneal shunt in patients with hydrocephalus: prospective study of 35 patients.

OBJECTIVE: To compare the cerebral blood flow velocity and pulsatility index in patients with hydrocephalus and to correlate the blood flow velocity to shunt function and size of ventricles in CT.
METHODS: The study comprised 16 children and 19 adults, preoperative (transcranial Doppler, TCD) disclosed normal pulsatility index in six and raised pulsatility index in 29 patients. Preoperative CT showed moderate hydrocephalus in 32 and severe hydrocephalus in three patients. All patients had CT and TCD 36-48 hours after their shunt operation.
RESULTS: A marked reduction in pulsatility index occurred postoperatively in 28 patients, all of them showed a significant decrease in ventricular size on postoperative CT done simultaneously. Mild or no reduction of pulsatility index was recorded in seven patients and none of them showed decreased ventricular size on postoperative CT. In two patients subsequent shunt blockage was accompanied by appropriate changes in both pulsatility index and CT, which reversed after successful shunt revision.
CONCLUSION: Fall in pulsatility index correlated well with decrease in ventricle size. Thus TCD can be used as a simple, bedside test for the assessment of shunt function.