Article
Is decreased ventricular volume a correlate of positive clinical outcome following shunt placement in cases of normal pressure hydrocephalus?
Korreliert die Abnahme der Ventrikelgröße mit einem positiven Krankheitsverlauf bei Patienten nach Shunt-Operation wegen Normaldruckhydrozephalus?
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Published: | April 23, 2004 |
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Outline
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Objective
It is well known that in patients with communicating hydrocephalus or normal pressure hydrocephalus, ventricular volume decreases following implantation of differential pressure valved shunts.
Methods
Hydrostatic valves (Miethke dual-switch valves) were implanted in 100 normal pressure hydrocephalus patients at the Unfallkrankenhaus Berlin between September 1997 and July 2002. One year postoperatively, these patients underwent CT scan, and their ventricular size was ascertained using the Evans index.
Results
Although 75% of these patients showed no postoperative change in ventricular volume, 59% nonetheless showed good to excellent clinical improvement, 20% satisfactory improvement and 21% no improvement. A moderate reduction in ventricular size was observed in 16% of the patients in our cohort. 50% of these patients showed good to excellent clinical improvement, 25% satisfactory improvement, and 25% unsatisfactory improvement. A marked reduction in ventricular size was observed in 9% of our patients. Of these latter patients, 68% showed good to excellent outcomes, and 11% satisfactory improvement while 11% had unsatisfactory outcomes.
Conclusions
The favorable outcomes following implantation of a hydrostatic valve in patients with normal pressure hydrocephalus did not correlate with decreased ventricular volume one year after operation. Better clinical outcomes were observed in patients with little or no alteration in ventricular size than in patients with a marked decrease in ventricular size. Postoperative change in ventricular volume should be assessed differently for patients with normal pressure hydrocephalus than in patients with hypertensive hydrocephalus.