Abnormal Intracranial Pulse Pressure Amplitude Despite Normalized Static Intracranial Pressure in Idiopathic Intracranial Hypertension Refractory to Conservative Medical Therapy.

Per Kristian Eide

doi:10.3390/life11060537

Per Kristian Eide

Open Access

https://doi.org/10.3390/life11060537

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Journal: Life	Publication Date: Jun 9, 2021
Citations: 9	License type: CC BY 4.0

Affiliation: Oslo University Hospital, University of Oslo

Abstract

Idiopathic intracranial hypertension (IIH) incorporates symptoms and signs of increased intracranial pressure (ICP) and is diagnosed by increased lumbar cerebrospinal fluid pressure. However, our knowledge about the characteristics of ICP abnormality, e.g., changes in pulsatile versus static ICP, remains scarce. This study questioned how overnight pulsatile ICP (mean ICP wave amplitude, MWA) associates with static ICP (mean ICP) in IIH patients who were refractory to conservative medical treatment. The material included 80 consecutive IIH patients undergoing ICP monitoring prior to shunt, as part of work-up for failed conservative medical therapy. In this group, the overnight mean ICP was normalized in 52/80 patients, but with abnormal overnight MWA in 45 of the 52 patients. Even though there was a positive correlation between MWA and mean ICP at group level and within individual ICP recordings, the levels of MWA were abnormal in a high proportion of patients despite normalized mean ICP. Taken together, the present results disclosed lasting abnormal pulsatile ICP despite normalized static ICP in IIH patients refractory to conservative medical therapy, which may reflect the underlying pathophysiology. It is tentatively suggested that abnormal pulsatile ICP in IIH may reflect alterations at the glia–neurovascular interface, resulting in impaired astrocytic pulsation absorber mechanisms.

Highlights

Idiopathic intracranial hypertension (IIH) is a brain disease characterized by symptoms and signs of increased intracranial pressure (ICP), including headache, visual failure, papilledema and sometimes sixth nerve palsy [1,2], and symptoms such as olfactory dysfunction, pulsatile tinnitus and cognitive impairment [2,3,4,5,6]
The study includes 80 consecutive patients who had fulfilled the diagnostic criteria of IIH disease [1], in whom overnight ICP measurements were performed prior to shunt surgery due to failed conservative medical treatment
This study showed that a significant proportion of IIH patients being refractory to conservative medical therapy presented with abnormal pulsatile ICP despite normalized static ICP

Summary

Introduction

Idiopathic intracranial hypertension (IIH) is a brain disease characterized by symptoms and signs of increased intracranial pressure (ICP), including headache, visual failure, papilledema and sometimes sixth nerve palsy [1,2], and symptoms such as olfactory dysfunction, pulsatile tinnitus and cognitive impairment [2,3,4,5,6]. Current treatment strategies aim at reducing the increased ICP, either by conservative measures, e.g., weight reduction, or by medicalinduced reduction in CSF production, e.g., acetazolamide medication [1,2,6]. Some IIH patients are refractory to conservative medical treatment and become candidates for surgical interventions such as shunt surgery, optical nerve sheet fenestration or the stenting of dural sinus veins [1,7]. A deeper understanding of the pathophysiology of IIH is needed to provide more efficient treatment

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