Naslov
Anatomy and physiology of interstitial and cerebrospinal fluid

Autori
Klarica, Marijan ; Milan Radoš ; Darko , Orešković

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Book of abstract / - , 2022, 1-1

Skup
ISMRM Workshop on Neurofluids: Anatomy, Physiology & Imaging

Mjesto i datum
Rome, Italy, 21.09.2022. - 24.09.2022

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
cerebrospinal fluid, choroid plexus, arachnoid granulations

Sažetak
Purpose: It is assumed that the choroid plexus, the patency of the cerebrospinal fluid (CSF) space and the arachnoid granulations of the dural sinuses are the key anatomical structures responsible for the constant formation, unidirectional circulation and passive absorption of CSF into the dural venous sinuses. All interpretations and therapeutic approaches to CSF- related diseases are based on this concept. Our experimental and clinical results raise the question of the validity of this concept. Methods, Results and Discussion: Our research on large experimental animals using markers of different molecular weights and the results of several other research groups using advanced neuroradiological techniques indicate that CSF movement is not present as a slow unidirectional circulation but a permanent rhythmic systolic- diastolic pulsation in all directions. Such movement also represents the main force of substance distribution within the CSF system. Transport mechanisms situated on the microvessels inside the central nervous system (CNS) parenchyma play a crucial role in substance elimination from the CSF and interstitial fluid (ISF) compartments, which freely communicate. Pharmacological manipulation suggests that the residence time and the substance travel distance along the CSF system depend on the capacity of transport mechanisms situated on CNS blood capillaries. In addition, manipulating osmotic and hydrostatic pressures in capillaries and the cerebrospinal fluid system over surfaces of different sizes indicate that these forces are responsible for regulating CSF volume. Due to their small surface area, physiological absorption of the CSF into the venous sinuses and lymphatics should be of minor importance compared with the enormous potential absorptive surface area of the microvessel network. This conclusion is supported by the radiological analysis of arachnoid granulations, which indicates that most people at a young age and a significant number of individuals in adulthood do not have or have several granulations in the dural sinuses. In contrast, in old age, more than 50% of granulations end in cranial bones. According to the classical hypothesis, the existence of active CSF secretion in the choroid plexuses should lead to the development of triventricular hydrocephalus after experimental (animals) or pathological (patients) occlusion of the aqueduct, which does not occur according to our results. Conclusion: Experimental, clinical and radiological findings point out that classical hypothesis of CSF physiology is not able to explain numerous phenomena and cases which shows the necessity for new approaches to this problem. Recently formulated Bulat-Klarica-Orešković hypothesis of CSF/ISF physiology can explain many observed controversies. According to this hypothesis, CSF production and absorption (CSF exchange) are constant and present everywhere in the CSF system (although the choroid plexus partially contributes to production of CSF), CSF is mainly formed as a consequence of water filtration between the capillaries and CSF/ISF.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti

POVEZANOST RADA