Gregory J. Zipfel
Leonie Gölz, Finn-Hannes Ruppert, Ullrich Meier and Johannes Lemcke
Shunt therapy in idiopathic normal pressure hydrocephalus (iNPH) can improve symptoms in 84% of patients 1 year postoperatively. Therefore, implantation of a ventriculoperitoneal shunt (VPS) prevents or at least prolongs the time during which patients are not dependent on care from others because of gait disorder or dementia. In this study, the medium-term results of modern shunt therapy were evaluated.
The authors retrospectively studied outcome in iNPH patients in whom VPSs were implanted. At yearly follow-up examinations over at least 6 years, clinical symptoms were recorded according to the NPH recovery rate (NPH-RR): (preoperative Kiefer Scale [KS] score − postoperative KS score)/(preoperative KS score × 10). Time and cause of death over this period were also analyzed.
Among the 147 patients treated for iNPH in the period between 1997 and 2006, 69 had died at the time of the authors' survey. Sixty-one patients reached the 6-year examination. The median age was 64 years (range 33–83 years) at the time of VPS implantation and 73 years (range 41–91 years) at the time of this study. Six years after shunt implantation, the median KS score was significantly lower than the preoperative score (4.3 vs 8.1 points). Fifty-nine percent of 61 patients had an excellent outcome, 15% had satisfactory benefit, and 26% had unsatisfactory results 6 years postoperatively. Three of the 147 patients who underwent implantation of a VPS died of cerebral diseases 4–10 years postoperatively.
Implantation of a VPS is a safe procedure and can improve symptoms in 74% of patients with iNPH in the longer term.
Ullrich Meier and Sven Mutze
Object. It is well known that in patients with communicating hydrocephalus or normal-pressure hydrocephalus (NPH), ventricular size decreases following implantation of shunts with differential pressure valves. The aim of this study was to determine whether ventricular size correlates with a positive clinical outcome following shunt placement.
Methods. Hydrostatic valves (dual-switch valves) were implanted in 80 patients with NPH at Unfallkrankenhaus, Berlin, between September 1997 and January 2002. One year postoperatively, these patients underwent computerized tomography scanning, and their ventricular size was ascertained using the Evans Index.
Among 80% of the patients who showed no postoperative change in ventricular volume, 59% nonetheless had good to excellent clinical improvements, 17% satisfactory improvement, and 24% no improvement. Furthermore, a moderate reduction in ventricular size was observed in 14% of patients in this cohort. Among these, 36% experienced good to excellent clinical improvements, 28% satisfactory improvement, and 36% unsatisfactory improvement. A marked reduction in ventricular size was observed in 6% of the patients. Of this latter group, 60% demonstrated good to excellent outcomes, whereas 40% had unsatisfactory outcomes.
Conclusions. Favorable outcomes following the implantation of a hydrostatic shunt in patients with NPH did not correlate with decreased ventricular volume 1 year after surgery. In fact, better clinical outcomes were observed in patients with little or no alteration in ventricular size, compared with those in patients with a marked decrease in ventricular size. A postoperative change in ventricular volume should be assessed differently in patients with NPH compared with those suffering from hypertensive hydrocephalus.