engleski

Role of MR volumetry in the study of cerebrospinal fluid pathophysiology

In prevous investigations on cats and a new artificial model of craniospinal space we observed that when craniaospinal arrangement was changed from horizontal to vertical position, displacement of the cerebrospinal flid (CSF) volume from cervical to lubar region takes place. Thus, as consequence of vertical position the lumbar sac is distended due to increase of CSF volume while cervical CSF volume decreased without changes of CSF volume in nondistensible crainal container. This cervicolumbar displacement of CSF volume during day activity should contribute to spinal CSF mixing and distribution of substances besides substance distribution promated by systolic-diastolic, craniospinal to-and-fro pulsations of CSF. Since cranial CSF volume is not changed during change of body position, this would indicate that distribution of substances in cranial CSF should be slower than in spinal CSF. Furthermore, we have found that increase of cranial CSF pressure is observed only when spinal intradural volume is filled up, and that increase or decrease of spinal CSF volume cause augmentation or fall of cranial CSF pressure. Thus, it appears that intracranial CSF pressure depends on total CSF volume in craniospinal space and that spinal CSF space is main regulatory factor in pathophysiology of intracranial hypertension. MR volumetry shows that brain ventricles contain 25 ml of CSF, while in cranial subarachnoid space about 90 ml of CSF is present, and that these CSF volumes increase during senescence. Furthermore, according to MR volumetry measurements about 50 ml of CSF is contained in lumbar space (from T12 to the sacral terminus of dural sac). It would appear that volume of spinal CSF in man is significantly larger than previously assumed. In the further investigations it is necessery to determine total CSF volume in craniospinal space under normal pressure, and changes of CSF volume in cranial and spinal space during increase and decrease of CSF pressure. In such a way the pathophysiological role of spinal CSF space in various pathological processes (e.g. intracranial hypertension, neurotrauma, intracranial bleeding and hydrocephlus) could be estimated.

MR ; Volumetry ; CSF

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