Validation of Davson’s equation in patients suffering from idiopathic normal pressure hydrocephalus

Afroditi Despina Lalou, Virginia Levrini, Matthew Garnett, Eva Nabbanja, Dong Ju Kim, Laurent Gergele, Anna Bjornson, Zofia Czosnyka, Marek Czosnyka

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


Introduction: The so-called Davson’s equation relates baseline intracranial pressure (ICP) to resistance to cerebrospinal fluid outflow (Rout), formation of cerebrospinal fluid (I f ) and sagittal sinus pressure (P SS ) There is a controversy over whether this fundamental equation is applicable in patients with normal pressure hydrocephalus (NPH). We investigated the relationship between Rout and ICP and also other compensatory, clinical and demographic parameters in NPH patients. Method: We carried out a retrospective study of 229 patients with primary NPH who had undergone constant-rate infusion studies in our hospital. Data was recorded and processed using ICM+ software. Relationships between variables were sought by calculating Pearson product correlation coefficients and p values. Results: We found a significant, albeit weak, relationship between ICP and Rout (R = 0.17, p = 0.0049), Rout and peak-to-peak amplitude of ICP (AMP) (R = 0.27, p = 3.577e-05) and Rout and age (R = 0.16, p = 0.01306). Conclusions: The relationship found between ICP and Rout provides indirect evidence to support disturbed Cerebrospinal fluid circulation as a key factor in disturbed CSF dynamics in NPH. Weak correlation may indicate that other factors—variable P SS and formation of CSF outflow—contribute heavily to linear model expressed by Davson’s equation.

Original languageEnglish
Pages (from-to)1097-1103
Number of pages7
JournalActa neurochirurgica
Issue number5
Publication statusPublished - 2018 May 1

Bibliographical note

Funding Information:
Funding MC and DJK are supported by a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health and Welfare, Republic of Korea (grant number: HI17C1790).

Publisher Copyright:
© 2018, Springer-Verlag GmbH Austria, part of Springer Nature.


  • Davson’s equation
  • Intracranial pressure
  • Normal pressure hydrocephalus
  • Resistance to CSF outflow

ASJC Scopus subject areas

  • Surgery
  • Clinical Neurology


Dive into the research topics of 'Validation of Davson’s equation in patients suffering from idiopathic normal pressure hydrocephalus'. Together they form a unique fingerprint.

Cite this