Cerebral hemodynamics before and after shunting in normal pressure hydrocephalus

Objective - To study the relationship between cerebral hemodynamics and clinical performance in normal pressure hydrocephalus (NPH), before and after surgery. Material and methods - Ten patients were studied prospectively before and 3 months after shunt surgery by means of transcranial Doppler (TCD). Clinical performance was scored by means of an NPH scale and the modified Rankin scale. Results - Peak systolic and mean cerebral blood flow velocity (MCV) were lower and cerebrovascular CO2 reactivity was higher after shunt surgery. The three patients with clinical improvement had higher preoperative end diastolic cerebral blood flow velocity and MCV. All postoperative cerebral blood flow velocities were higher in patients with clinical improvement. Conclusion - Our data suggest that higher cerebral blood flow velocity before surgery in patients with NPH is related to clinical improvement after shunt surgery. Cerebral hemodynamic parameters may develop into predictors of successful shunt surgery in patients with normal pressure hydrocephalus.