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61st Annual Meeting of the German Society of Neurosurgery (DGNC) as part of the Neurowoche 2010
Joint Meeting with the Brazilian Society of Neurosurgery on the 20 September 2010

German Society of Neurosurgery (DGNC)

21 - 25 September 2010, Mannheim

Idiopathic normal pressure hydrocephalus (iNPH) and co-morbidity – an outcome analysis of 134 patients

Meeting Abstract

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  • Ullrich Meier - Klinik für Neurochirurgie, Unfallkrankenhaus Berlin, Deutschland
  • Johannes Lemcke - Klinik für Neurochirurgie, Unfallkrankenhaus Berlin, Deutschland

Deutsche Gesellschaft für Neurochirurgie. 61. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC) im Rahmen der Neurowoche 2010. Mannheim, 21.-25.09.2010. Düsseldorf: German Medical Science GMS Publishing House; 2010. DocP1782

doi: 10.3205/10dgnc253, urn:nbn:de:0183-10dgnc2537

Published: September 16, 2010

© 2010 Meier et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Objective: The diagnosis and management of idiopathic normal-pressure hydrocephalus (iNPH) remains controversial, particularly in selecting patients for shunt insertion. Diagnostic criteria target the pathology of the dynamics of the cerebrospinal fluid (CSF), however the effectiveness in predicting shunt success has room for improvement. The aim of our study was to systematically assess the influence of the co-morbidity determining the benefit from shunt surgery.

Methods: Between 1997 and 2006 one hundred thirty-four patients suffering from iNPH were treated with a ventriculo-peritoneal shunt with a gravity-controlled valve. The coincident disease processes were recorded. Shunt outcome was assessed at 2 years postsurgery in 116 patients (follow up rate 87%). The results of this follow-up examination (Kiefer Score, NPH Recovery Rate) were compared with the preoperative Co-Morbidity Index (CMI).

Results: Of the 134 patients 76 (56.7%) had a CMI of 0 - 3 and 58 patients (43.3%) had a CMI of 4–8. Two years after surgery 65 of 70 shunt responders (93%) could be identified in the patients group with a CMI of 0-3 and only 29 of 46 (63%) in group with a CMI of 4–8. This difference was significant (p<0.0001). Remarkably few patients scoring between 6-8 on the CMI scale experienced a favourable outcome. The patients in this latter group showed excellent outcomes in only 1% and poor outcomes in 33%.

Conclusions: Data in this report affirm that co-morbidity is a statistically significant predictor of the quality of the clinical outcome for patients with iNPH undergoing shunt therapy. A CMI of more than 3 significantly decreases the chance of a favourable outcome and this should form part of the assessment when the risks and benefits of surgery are considered. According to these data, a successful outcome in patients with a CMI of 6 or more is not to be expected.