University of Oulu

Junkkari, A., Luikku, A.J., Danner, N. et al. The Kuopio idiopathic normal pressure hydrocephalus protocol: initial outcome of 175 patients. Fluids Barriers CNS 16, 21 (2019).

The Kuopio idiopathic normal pressure hydrocephalus protocol : initial outcome of 175 patients

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Author: Junkkari, A.1; Luikku, A. J.1; Danner, N.1;
Organizations: 1Neurosurgery of NeuroCenter, Kuopio University Hospital (KUH) and University of Eastern Finland (UEF), POB 100, 70029, Kuopio, Finland
2Department of Pathology, KUH and UEF, Kuopio, Finland
3Neurology of NeuroCenter, KUH and UEF, Kuopio, Finland
4Unit of Clinical Neuroscience, Neurosurgery, University of Oulu, Oulu, Finland
5MRC Oulu, Oulu University Hospital, Oulu, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 0.7 MB)
Persistent link:
Language: English
Published: Springer Nature, 2019
Publish Date: 2020-04-20


Background: The Kuopio University Hospital (KUH) idiopathic normal pressure hydrocephalus (iNPH) cerebrospinal fluid (CSF) shunting protocol is described together with the initial outcomes of 175 patients with probable iNPH treated according to this protocol from a defined population. Our secondary aim was to display the variety of differential diagnoses referred to the KUH iNPH outpatient clinic from 2010 until 2017.

Methods: Patients were divided into four groups according to the prognostic tests: tap test (positive or negative) and infusion test (positive or negative). The short-term outcome was compared between groups. The 3-month outcome following shunt surgery was assessed by measuring gait speed improvement, using a 12-point iNPH grading scale (iNPHGS) and the 15D instrument.

Results: From 341 patients suspected of iNPH, 88 patients were excluded from further research mostly due to deviation from the protocol’s gait assessment guidelines. Hence 253 patients with suspected iNPH were included in the study, 177/253 (70%) of whom were treated with a CSF shunt. A favorable clinical outcome following surgery was observed in 79–93% of patients depending on the prognostic group. A moderate association (Cramer’s V = 0.32) was found between the gait speed improvement rate and the prognostic group (X2, p = 0.003). Patients with a positive tap test had the highest gait speed improvement rate (75%). In addition, an improvement in walking speed was observed in 4/11 patients who had both a negative tap test and a negative infusion test. Other outcome measures did not differ between the prognostic groups. Conditions other than iNPH were found in 25% of the patients referred to iNPH outpatient clinic, with the most prevalent being Alzheimer’s disease.

Conclusions: Our results emphasize the importance of a systematic diagnostic and prognostic workup especially in cases with an atypical presentation of iNPH. Additional diagnostic testing may be required, but should not delay adequate care. Active surgical treatment is recommended in patients with a high clinical probability of iNPH. Other neurological conditions contributed to most of the non iNPH diagnoses.

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Series: Fluids and barriers of the CNS
ISSN: 2045-8118
ISSN-E: 2045-8118
ISSN-L: 2045-8118
Volume: 16
Article number: 21
DOI: 10.1186/s12987-019-0142-9
Type of Publication: A1 Journal article – refereed
Field of Science: 3112 Neurosciences
3124 Neurology and psychiatry
Funding: This study was supported by the Kuopio University Hospital; State Research Funding (VTR Fund); and the Finnish Medical Foundation.
Copyright information: © The Author(s) 2019. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated.