Spontaneous Intracranial Hypotension Without CSF Leakage-Concept of a Pathological Cranial to Spinal Fluid Shift.

Johannes Goldberg,Christopher Marvin Jesse,Tomas Dobrocky,Andreas Raabe,Jan Gralla,Jürgen Beck,Eike I Piechowiak,Levin Häni,Irena Zubak

doi:10.3389/fneur.2021.760081

Abstract

Objective: Spontaneous intracranial hypotension (SIH) is typically caused by CSF leakage from a spinal dural tear, a meningeal diverticulum, or a CSF venous fistula. However, some patients present with classic orthostatic symptoms and typical intracranial imaging findings without evidence of CSF leakage despite repeated diagnostic work-up. This article aims to elaborate a hypothesis that would explain a pathologically increased orthostatic shift of CSF from the cranial to the spinal compartment in the absence of a CSF leak.Medical Hypothesis: The symptoms of SIH are caused by a decrease in intracranial CSF volume, intracranial hypotension, and downward displacement of intracranial structures. A combination of pathologically increased spinal compliance, decreased intracranial CSF volume, low CSF outflow resistance, and decreased venous pressure might result in a pathological orthostatic cranial-to-spinal CSF shift. Thus, in rare cases, intracranial hypotension may occur in the absence of CSF leakage from the dural sac.Conclusion: We propose a pathophysiological concept for the subgroup of SIH patients with typical cranial imaging findings and no evidence of CSF leakage. In these patients, reducing the compliance or the volume of the spinal compartment seems to be the appropriate therapeutic strategy.

Highlights

Orthostatic headache is the hallmark of headache attributed to spontaneous intracranial hypotension (SIH) as defined by the third edition of the international classification of headache disorders (ICHD-3) category 7.2.3 [1]
Are recommended to search for spinal CSF leaks that are amenable to surgical treatment like ventral dural tears, ruptured meningeal diverticula, or a direct CSF to venous fistula [4, 7,8,9,10,11]
In some patients with intractable SIH symptoms and typical cranial imaging findings [12], no evidence of spinal CSF leakage can be found despite repeated diagnostic work-up (Figure 1)

Summary

Objective

Spontaneous intracranial hypotension (SIH) is typically caused by CSF leakage from a spinal dural tear, a meningeal diverticulum, or a CSF venous fistula. Some patients present with classic orthostatic symptoms and typical intracranial imaging findings without evidence of CSF leakage despite repeated diagnostic work-up. This article aims to elaborate a hypothesis that would explain a pathologically increased orthostatic shift of CSF from the cranial to the spinal compartment in the absence of a CSF leak. Medical Hypothesis: The symptoms of SIH are caused by a decrease in intracranial CSF volume, intracranial hypotension, and downward displacement of intracranial structures. A combination of pathologically increased spinal compliance, decreased intracranial CSF volume, low CSF outflow resistance, and decreased venous pressure might result in a pathological orthostatic cranial-to-spinal CSF shift. In rare cases, intracranial hypotension may occur in the absence of CSF leakage from the dural sac

Conclusion

INTRODUCTION

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DATA AVAILABILITY STATEMENT