886 research outputs found
Cerebrospinal fluid dynamics
The classical cerebrospinal fluid (CSF) circulation theory
has been accepted as an established theory of CSF physiology. It describes bulk CSF flow from production site to absorption site. However, much controversy remains regarding the basic CSF physiology and the mechanisms behind
the development of hydrocephalus. In the recent observations made using advanced magnetic resonance imaging
(MRI) technique, namely, the time spatial inversion pulse
(Time-SLIP) method, CSF was used as internal CSF tracer to
trace true CSF movement. Observation of the CSF dynamics using this method reveals aspects of CSF dynamics that
are different from those of classical CSF circulation theory. Cerebrospinal fluid shows pulsation but does not show
bulk flow from production site to absorption site, a theory
that was built upon externally injected tracer studies. Observation of the exogeneous tracer studies were true but
misinterpreted. Causes of misinterpretations are the differences between results obtained using the true CSF tracer
and exogenous tracers. A better understanding of the real
CSF physiology can be significant for the advancement of
medical sciences in the future. Revisiting CSF flow physiology is a necessary step toward this goal
TIME TO LIFT LEG DEPENDS ON INITIAL WEIGHT DISTRIBUTION
INTRODUCTION: If you are a defensive player of football or basketball, you must have an experience that you were impotently left behind the offensive player while you certainly knew he/she cut back to left and you should have stepped to left. Why this happen? As a basic research to answer this question, we conducted the lift-one-leg task from quiet standing with and without visual feedback of weight distribution. We hypothesized that the time to lift leg depends on the initial weight distribution. The aim of the present study is to investigate if and how much the initial weight distribution during quiet standing influences the time to lift leg
Cerebrospinal fluid physiology: visualization of cerebrospinal fluid dynamics using the magnetic resonance imaging Time-Spatial Inversion Pulse method
Previously there have been no methods for directly tracing
the flow of cerebrospinal fluid (CSF) under physiological
conditions, and the circulation of CSF has therefore been
studied and visualized by injecting a radioactively labeled
tracer or contrast medium visible in x-ray images. The
newly developed Time-Spatial Inversion Pulse (Time-SLIP)
method makes it possible to directly visualize the flow of
CSF using magnetic resonance imaging (MRI), permitting
CSF dynamics to be depicted in a certain time frame. The
CSF dynamics visualized using Time-SLIP has been found
to differ markedly from the classical CSF circulation theory
described in medical textbooks. It can be said that research
on CSF dynamics has advanced to the next stage
with the use of this innovative imaging method. Obtaining
a more accurate understanding of normal CSF physiology
and pathophysiology should lead to improved diagnostic
accuracy, permit the identification of new etiological factors
in a variety of diseases, and promote the development
of new therapeutic approaches
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