Original scientific paper
https://doi.org/10.3325/cmj.2014.55.317
Measurement of cerebrospinal fluid formation and absorption by ventriculo-cisternal perfusion: what is really measured?
Darko Orešković
; Ruđer Bošković Institute Department of Molecular Biology, Zagreb, Croatia
Marijan Klarica
; Department of Pharmacology and Croatian Institute for BrainResearch, University of Zagreb School of Medicine, Zagreb, Croatia
Abstract
The generally accepted hypothesis on cerebrospinal fluid
(CSF) hydrodynamics suggests that CSF is actively formed
mainly by the choroid plexuses, circulates unidirectionally
along the brain ventricles and subarachnoid space, and is
passively absorbed mainly into the dural venous sinuses.
CSF formation rate (Vf ) has been extensively studied using
the ventriculo-cisternal perfusion technique and the results
have been used as the key evidence confirming the
mentioned hypothesis. This technique and the equation
for Vf calculation are based on the assumption that the dilution
of the indicator substance is a consequence of the
newly formed CSF, ie, that a higher CSF formation rate will
result in a higher degree of dilution. However, it has been
experimentally shown that the indicator substance dilution
inside the CSF system does not occur because of a
“newly formed” CSF, but as consequence of a number of
other factors (departure of substances into the surrounding
tissue, flowing around the collecting cannula into the
cortical and spinal subarachnoid space, departure into the
contralateral ventricle, etc). This technique allows “calculation”
of the CSF formation even in dead animals, in an in vitro
model, and in any other part of the CSF system outside
the ventricles that is being perfused. Therefore, this method
is indirect and any dilution of the indicator substance
in the perfusate caused by other reasons would result in
questionable and often contradictory conclusions regarding
CSF formation rates.
Keywords
Hrčak ID:
129938
URI
Publication date:
15.8.2014.
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