Assessment of cerebrospinal fluid outflow conductance using an adaptive observer--experimental and clinical evaluation.

Abstract:

:Idiopathic normal pressure hydrocephalus (INPH) patients have a disturbance in the dynamics of the cerebrospinal fluid (CSF) system. The outflow conductance, C, of the CSF system has been suggested to be prognostic for positive outcome after treatment with a CSF shunt. All current methods for estimation of C have drawbacks; these include lack of information on the accuracy and relatively long investigation times. Thus, there is a need for improved methods. To accomplish this, the theoretical framework for a new adaptive observer (OBS) was developed which provides real-time estimation of C. The aim of this study was to evaluate the OBS method and to compare it with the constant pressure infusion (CPI) method. The OBS method was applied to data from infusion investigations performed with the CPI method. These consisted of repeated measurements on an experimental set-up and 30 patients with suspected INPH. There was no significant difference in C between the CPI and the OBS method for the experimental set-up. For the patients there was a significant difference, -0.84+/-1.25 microl (s kPa)(-1), mean +/- SD (paired sample t-test, p<0.05). However, such a difference is within clinically acceptable limits. This encourages further development of this new real-time approach for estimation of the outflow conductance.

journal_name

Physiol Meas

authors

Andersson K,Manchester IR,Andersson N,Shiriaev A,Malm J,Eklund A

doi

10.1088/0967-3334/28/11/003

subject

Has Abstract

pub_date

2007-11-01 00:00:00

pages

1355-68

issue

11

eissn

0967-3334

issn

1361-6579

pii

S0967-3334(07)52766-8

journal_volume

28

pub_type

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