Perioptic Cerebrospinal Fluid Dynamics in Idiopathic Intracranial Hypertension.

Achmed Pircher,Luca Remonda,Hanspeter E Killer,Joachim Pircher,Margherita Montali,Jatta Berberat

doi:10.3389/fneur.2018.00506

Abstract

Purpose: To examine the cerebrospinal fluid (CSF) dynamics along the entire optic nerve in patients with idiopathic intracranial hypertension (IIH) and papilledema by computed tomographic (CT) cisternography.Methods: Retrospective analysis of CT cisternographies in 16 patients with a history of IIH and papilledema (14 females and 2 males, mean age: 49 ± 16 years). Contrast loaded CSF (CLCSF) was measured in Hounsfield Units (HU) at three defined regions of interest (ROI) along the optic nerve (orbital optic nerve portion: bulbar and mid-orbital segment, intracranial optic nerve portion) and additionally in the basal cistern. The density measurements in ROI 1, ROI 2, and ROI 3 consist of measurements of the optic nerve complex: optic nerve sheath, CLCSF filled SAS and optic nerve tissue. As controls served a group of patients (mean age: 60 ± 19 years) without elevated intracranial pressure and without papilledema.Results: In IIH patients the mean CLCSF density in the bulbar segment measured 65 ± 53 HU on the right and 63 ± 35 HU on the left side, in the mid-orbital segment 68 ± 37 HU right and 60 ± 21 HU left. In the intracranial optic nerve portion 303 ± 137 HU right and 323 ± 169 HU left and in the basal cistern 623 ± 188 HU. Within the optic nerve the difference of CLCSF density showed a highly statistical difference (p < 0.001) between the intracranial optic nerve portion and the mid-orbital segment. CLCSF density was statistically significantly (p < 0.001) reduced in both intraorbital optic nerve segments in patients with IIH compared to controls.Conclusions: The current study demonstrates reduced CLCSF density within the orbital optic nerve segments in patients with IIH and papilledema compared to 12 controls without elevated intracranial pressure and without papilledema. Impaired CSF dynamics could be involved in the pathophysiology of optic nerve damage in PE in IIH.

Highlights

Idiopathic intracranial hypertension (IIH) is a neurological disorder characterized by elevated intracranial pressure (ICP) in the absence of any known causative factor
The development of papilledema is thought to depend on the transmission of elevated ICP via the subarachnoid space (SAS) to the lamina cribrosa with resulting damage to axonal transport [7]
From 2005 to 2015 16 patients (32 optic nerves), 14 women and 2 men with an established diagnosis of IIH were admitted to our department for computer tomographic (CT) cysternography because of a therapyresistant papilledema and progressive visual impairment

Summary

Introduction

Idiopathic intracranial hypertension (IIH) is a neurological disorder characterized by elevated intracranial pressure (ICP) in the absence of any known causative factor (mass lesion, inflammation, central venous thrombosis). Patients with IIH develop papilledema, that if left untreated, may lead to permanent visual loss [3,4,5,6]. The development of papilledema is thought to depend on the transmission of elevated ICP via the subarachnoid space (SAS) to the lamina cribrosa with resulting damage to axonal transport [7]. This theory assumes a free CSF circulation through the optic canal between the intracranial SAS and the orbital SAS of the optic nerve

Methods

Results

Conclusion