Proposal of “evolution theory in cerebrospinal fluid dynamics” and minor pathway hydrocephalus in developing immature brain

Abstract

The various basic investigations in rodents, cats and monkeys have suggested that CSF is absorbed not via Pacchionian bodies as the last end of the major pathway, which do not exist in these animals and are recognized after infantile period in human, but through the choroids plexus and the periventricular fenestrated venous capillaries into the deep venous channel. The high incidence of "failure to arrest hydrocephalus" by neuroendoscopic ventriculostomy in fetal, neonatal and infantile periods was considered to depend on the specific CSF dynamics, in which the major CSF pathway has not developed and the minor pathway has a significant role. PROPOSAL OF THEORY: We herein propose a new aspect of classification for hydrocephalus with special reference to the CSF circulation in the minor CSF pathway, i.e. "minor pathway hydrocephalus", differentiating the conventional classification by Dandy (communicating and non-communicating) or Russell (non-obstructive and obstructive) as "major pathway hydrocephalus". We also herein propose a hypothesis that the CSF dynamics develop in the theory of evolution from the immature brain, as in the animals with the minor CSF pathway predominance, towards matured adult human brain together with completion of the major CSF pathway: the "evolution theory in CSF dynamics".

Endoscopic third ventriculostomy in the management of hydrocephalus: Outcome analysis of 168 consecutive procedures

“…Our success rate was 50% in infants, which overlaps with that reported in the literature. The reduced success rate among infants (particularly those below the age of six months) is likely due to (1) the fact that these patients exhibit a greater tendency to form new arachnoid membranes that lead to the obstruction of the stoma [68] and (2) to deficits in the reabsorption of CSF due to the immaturity of the arachnoid villi [59,69].…”

Syndrome of hydrocephalus in young and middle-aged adults: Review of the literature and illustrative cases

“…The developmental trend is reflected in the so called "Evolution theory in cerebrospinal fluid dynamics" proposed by Oi in 2006 (13). The author proposed the term "minor pathway" -the pattern of ventriculo-cisternography in neonatal/infantile cases revealed a predominantly intra-parenchymal pattern of CSF circulation, unlike the adult type of CSF circulation which is termed "Major pathway".…”

Hydrocephalus Research Update -Controversies in Definition and Classification of Hydrocephalus-

“…These two classifications are based on a concept to classify the type of hydrocephalus considering the disturbed CSF dynamics only in the major CSF pathway:``Major Pathway Hydrocephalus'' (Oi and Di Rocco, 2006). 14) Since the CSF dynamics during the fetal and neonatal/early infantile periods are mainly maintained in the``minor CSF pathway,'' hydrocephalus occurring during these periods can be defined as disturbed CSF circulation in the``minor CSF pathway'' (``Minor CSF Pathway Hydrocephalus'': Oi and Di Rocco, 2006). 14) Therefore, the mechanism or pathogenesis of hydrocephalus may be different from thè`M ajor CSF Pathway Hydrocephalus.''…”

“…14) II. Classification of fetal and congenital hydrocephalus The underlying lesions or causative factors may differ completely in the fetal or perinatal period from childhood and adulthood.…”