Does idiopathic normal pressure hydrocephalus always mean a poor prognosis?
OBJECTIVE
The objective was to assess whether idiopathic normal-pressure hydrocephalus (iNPH) has a worse prognosis than other forms of hydrocephalus, as has been suggested.


METHODS
A total of 125 patients with chronic hydrocephalus, 75 of whom suffered from iNPH and the remaining (non-INPH) from sNPH or non-communicating hydrocephalus, were shunted using gravitational valves. Clinical state was assessed with our clinical grading (KI) and a co-morbidity index (CMI). Average follow-up was 5.1 +/- 1.6 years.


METHODS
Spearman, Kruskal-Wallis, ANOVA, chi(2)- and the Wilcoxon U tests at a significance level of pi < 0.05 were used.


RESULTS
Shunt responder rates for iNPH and non-iNPH were 72% and 86%, respectively. With shorter anamnesis (< or =1 year) or preoperative KI < 6 points, iNPH patients had a similar or even better outcome than non-iNPH patients with longer anamnesis or a worse KI. Most impressive was the influence of co-morbidity: 86% of iNPH patients with a low CMI (< or =3 points) experienced clinical improvement after shunting, which was contrasted by a responder rate of 64% for non-iNPH with worse CMI.


CONCLUSIONS
The diagnosis of iNPH does not by itself mean a worse prognosis, and iNPH patients with favorable preconditions may have a similar or better prognosis than patients with any other kind of hydrocephalus. The worse overall clinical results of iNPH result from late recognition and in most instances worse preconditions.
Kiefer
Michael
M
Department of Neurosurgery, Saarland University Medical School, Homburg-Saar, Germany. Michael.Kiefer@uks.eu
Meier
Ulrich
U
Eymann
Regina
R
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002557:Cerebrospinal Fluid Shunts / Q000379:methods*; D018450:Disease Progression; D005260:Female; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000175:diagnosis* / Q000601:surgery*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult