Benign intracranial hypertension: a diagnostic dilemma

Causes and outcomes of revision surgery in subjects with pulsatile tinnitus

INTRODUCTION

Once the underlying pathology has been identified, pulsatile tinnitus (PT) can be treated successfully with surgical or interventional management. However, some patients experience residual or recurrent symptoms following initially successful surgical treatment, and require revision surgery or additional procedures. Here, we report a case series of patients who had undergone revision surgery or interventional treatment, and suggest possible ways of minimizing the need for revision.

METHODS

Between January 2014 and March 2023, a total of seven subjects underwent revision surgery or interventional treatment for persistent or recurrent PT after initial surgical treatment. Demographic data, reasons for revision, and changes in symptoms before and after revision were analyzed retrospectively. Temporal bone computed tomographic angiography images were reviewed to identify the causes and reasons for revision.

RESULTS

Of the seven subjects, six underwent sigmoid sinus (SS) resurfacing/reshaping due to ipsilateral diverticulum (Div) or dehiscence (Deh), and one underwent jugular bulb (JB) resurfacing due to a high-riding JB with bony Deh. Of the five subjects who underwent revision SS surgery due to recurrent SS-Div or SS-Deh, three showed marked resolution of PT, while the other two showed partial improvement of the symptoms. One subject who underwent revision JB resurfacing, and another who underwent additional transarterial embolization for a concurrent ipsilateral dural arteriovenous fistula, reported marked improvement of PT.

DISCUSSION

The possibility of recurrence should be taken into account when performing surgical intervention in patients with PT. The likelihood of recurrence can be minimized through a comprehensive evaluation to identify possible multiple etiologies, and through the use of durable materials and appropriate surgical methods.

The Paediatric Vault Score (PVS)-A Novel Scoring Tool for Prioritisation of Surgical Management of Craniosynostosis Patients

Craniosynostosis is the premature fusion of the skull sutures, resulting in abnormal skull shape and volume. Timely management is a priority in avoiding raised intracranial pressure which can result in blindness and neurodevelopmental delay. Due to the COVID-19 pandemic, theater access was reduced. A risk stratification scoring system was thus devised to score patients attending surgery and aid in prioritization according to surgical need. The authors present the Paediatric Vault Score (PVS), which can also be customized to each unit's individual protocols. Ten patients on the waiting list were randomly selected and their clinical information was summarized in uniform anonymized reports. Six craniofacial consultants were selected as assessors and given 1 week to independently rank the patients from 1 to 10. Each scorer's ranking was verified against the PVS template and concordance was analyzed using the Kendall tau correlation coefficient (KT). Three cycles of the scoring process were carried out. Improvements were made to the scoring tool following cycle 1. Cycle 1 revealed 2 clinicians to be concordant with the PVS system and 4 to be discordant. Cycle 2 revealed all 6 clinicians to be concordant, with a mean KT score of 0.61. The final cycle revealed all 6 clinicians to be concordant, with a mean KT score of 0.70. Four scorers increased their concordance once the scoring sheet was introduced. Kendall's correlation of concordance calculated the interrater reliability to be 0.81. The PVS is the first known vault scoring system to aid in risk stratification and waiting list prioritization.

Long-term recovery behavior of brain tissue in hydrocephalus patients after shunting

The unpredictable complexities in hydrocephalus shunt outcomes may be related to the recovery behavior of brain tissue after shunting. The simulated cerebrospinal fluid (CSF) velocity and intracranial pressure (ICP) over 15 months after shunting were validated by experimental data. The mean strain and creep of the brain had notable changes after shunting and their trends were monotonic. The highest stiffness of the hydrocephalic brain was in the first consolidation phase (between pre-shunting to 1 month after shunting). The viscous component overcame and damped the input load in the third consolidation phase (after the fifteenth month) and changes in brain volume were stopped. The long-intracranial elastance (long-IE) changed oscillatory after shunting and there was not a linear relationship between long-IE and ICP. We showed the long-term effect of the viscous component on brain recovery behavior of hydrocephalic brain. The results shed light on the brain recovery mechanism after shunting and the mechanisms for shunt failure.

A New Definition for Intracranial Compliance to Evaluate Adult Hydrocephalus After Shunting

The clinical application of intracranial compliance (ICC), ∆V/∆P, as one of the most critical indexes for hydrocephalus evaluation was demonstrated previously. We suggest a new definition for the concept of ICC (long-term ICC) where there is a longer amount of elapsed time (up to 18 months after shunting) between the measurement of two values (V1 and V2 or P1 and P2). The head images of 15 adult patients with communicating hydrocephalus were provided with nine sets of imaging in nine stages: prior to shunting, and 1, 2, 3, 6, 9, 12, 15, and 18 months after shunting. In addition to measuring CSF volume (CSFV) in each stage, intracranial pressure (ICP) was also calculated using fluid–structure interaction simulation for the noninvasive calculation of ICC. Despite small increases in the brain volume (16.9%), there were considerable decreases in the ICP (70.4%) and CSFV (80.0%) of hydrocephalus patients after 18 months of shunting. The changes in CSFV, brain volume, and ICP values reached a stable condition 12, 15, and 6 months after shunting, respectively. The results showed that the brain tissue needs approximately two months to adapt itself to the fast and significant ICP reduction due to shunting. This may be related to the effect of the “viscous” component of brain tissue. The ICC trend between pre-shunting and the first month of shunting was descending for all patients with a “mean value” of 14.75 ± 0.6 ml/cm H2O. ICC changes in the other stages were oscillatory (nonuniform). Our noninvasive long-term ICC calculations showed a nonmonotonic trend in the CSFV–ICP graph, the lack of a linear relationship between ICC and ICP, and an oscillatory increase in ICC values during shunt treatment. The oscillatory changes in long-term ICC may reflect the clinical variations in hydrocephalus patients after shunting.

Isolated spontaneous cerebrospinal fluid rhinorrhoea as a rare presentation of idiopathic intracranial hypertension: Case reports with comprehensive review of literature

Isolated cerebrospinal fluid (CSF) rhinorrhoea as a sole presenting symptom of idiopathic intracranial hypertension (IIH) is extremely rare. IIH typically presents with headache, pulsatile tinnitus, dizziness, nausea, vomiting, and visual disturbance. We report two cases which presented with acute onset spontaneous CSF rhinorrhoea without any other symptom. In addition, we discuss in detail imaging features of IIH with review of its literature.

CTA/V detection of bilateral sigmoid sinus dehiscence and suspected idiopathic intracranial hypertension in unilateral pulsatile tinnitus

PURPOSE

This aimed to evaluate the prevalence and extent of bilateral sigmoid sinus dehiscence (SSD) and to explore the presence of idiopathic intracranial hypertension (IIH) in patients with unilateral pulsatile tinnitus (PT) with CTA/V.

METHODS

Sixty PT patients (52 females; 40.4 ± 11.6 years [20-72]) who underwent CTA/V and 30 non-PT patients (27 females; 38.4 ± 14.7 years [12-62]) were enrolled in this study. The primary outcome measure was the radiographic presence of SSD. The index of transverse sinus stenosis (ITSS) was obtained by multiplying the stenosis scale values for each transverse sinus, and once was ≥ 4, the presence of IIH was suspected.

RESULTS

The prevalence and extent of SSD on symptomatic side (78%; maximum transverse diameter, MTD 0.49 ± 0.23; maximum vertical diameter, MVD 0.50 ± 0.26 cm) were significantly higher and larger than those on asymptomatic side (50%, P < 0.001; MTD 0.35 ± 0.18, P = 0.006; MVD 0.30 ± 0.15 cm, P < 0.001) in the study group and those (20%, P < 0.001; MTD 0.36 ± 0.18, P = 0.073; MVD 0.30 ± 0.22 cm, P < 0.048) in the control group. The presence of SSD showed significant correlation with both PT (logistic regression analysis, OR 4.167 [1.450-11.97]; P = 0.008) and suspected IIH (OR 16.25 [1.893-139.5]; P = 0.011).

CONCLUSION

In PT patients, SSD has a significant correlation with PT and a potential correlation with IIH.

Sigmoid Sinus Diverticulum, Dehiscence, and Venous Sinus Stenosis: Potential Causes of Pulsatile Tinnitus in Patients with Idiopathic Intracranial Hypertension?

BACKGROUND AND PURPOSE

Pulsatile tinnitus is experienced by most patients with idiopathic intracranial hypertension. The pathophysiology remains uncertain; however, transverse sinus stenosis and sigmoid sinus diverticulum/dehiscence have been proposed as potential etiologies. We aimed to determine whether the prevalence of transverse sinus stenosis and sigmoid sinus diverticulum/dehiscence was increased in patients with idiopathic intracranial hypertension and pulsatile tinnitus relative to those without pulsatile tinnitus and a control group.

MATERIALS AND METHODS

CT vascular studies of patients with idiopathic intracranial hypertension with pulsatile tinnitus (n = 42), without pulsatile tinnitus (n = 37), and controls (n = 75) were independently reviewed for the presence of severe transverse sinus stenosis and sigmoid sinus diverticulum/dehiscence according to published criteria. The prevalence of transverse sinus stenosis and sigmoid sinus diverticulum/dehiscence in patients with idiopathic intracranial hypertension with pulsatile tinnitus was compared with that in the nonpulsatile tinnitus idiopathic intracranial hypertension group and the control group. Further comparisons included differing degrees of transverse sinus stenosis (50% and 75%), laterality of transverse sinus stenosis/sigmoid sinus diverticulum/dehiscence, and ipsilateral transverse sinus stenosis combined with sigmoid sinus diverticulum/dehiscence.

RESULTS

Severe bilateral transverse sinus stenoses were more frequent in patients with idiopathic intracranial hypertension than in controls (P < .001), but there was no significant association between transverse sinus stenosis and pulsatile tinnitus within the idiopathic intracranial hypertension group. Sigmoid sinus dehiscence (right- or left-sided) was also more common in patients with idiopathic intracranial hypertension compared with controls (P = .01), but there was no significant association with pulsatile tinnitus within the idiopathic intracranial hypertension group.

CONCLUSIONS

While our data corroborate previous studies demonstrating increased prevalence of sigmoid sinus diverticulum/dehiscence and transverse sinus stenosis in idiopathic intracranial hypertension, we did not establish an increased prevalence in patients with idiopathic intracranial hypertension with pulsatile tinnitus compared with those without. It is therefore unlikely that these entities represent a direct structural correlate of pulsatile tinnitus in patients with idiopathic intracranial hypertension.

Controversies: Optic nerve sheath fenestration versus shunt placement for the treatment of idiopathic intracranial hypertension

BACKGROUND

Idiopathic intracranial hypertension (IIH) has been increasing in prevalence in the past decade, following the obesity epidemic. When medical treatment fails, surgical treatment options must be considered. However, controversy remains as to which surgical procedure is the preferred surgical option - optic nerve sheath fenestration (ONSF) or cerebrospinal fluid (CSF) shunting - for the long-term treatment of this syndrome.

PURPOSE

To provide a clinical update of the pros and cons of ONSF versus shunt placement for the treatment of IIH.

DESIGN

This was a retrospective review of the current literature in the English language indexed in PubMed.

METHODS

The authors conducted a PubMed search using the following terms: Idiopathic IIH, pseudotumor cerebri, ONSF, CSF shunts, vetriculo-peritoneal shunting, and lumbo-peritoneal shunting. The authors included pertinent and significant original articles, review articles, and case reports, which revealed the new aspects and updates in these topics.

RESULTS

The treatment of IIH remains controversial and lacks randomized controlled clinical trial data. Treatment of IIH rests with the determination of the severity of IIH-related visual loss and headache.

CONCLUSION

The decision for ONSF versus shunting is somewhat institution and surgeon dependent. ONSF is preferred for patients with visual symptoms whereas shunting is reserved for patients with headache. There are positive and negative aspects of both procedures, and a prospective, randomized, controlled trial is needed (currently underway). This article will hopefully be helpful in allowing the reader to make a more informed decision until that time.

A case series of dural venous sinus stenting in idiopathic intracranial hypertension: association of outcomes with optical coherence tomography

Purpose/Aim: Pseudotumor cerebri or idiopathic intracranial hypertension (IIH) is characterized by increased intracranial pressure of unknown etiology. A subset of patients has shown benefit from endovascular dural venous sinus stenting (DVSS). We sought to identify a population of IIH patients who underwent DVSS to assess outcomes.

MATERIALS AND METHODS

A retrospective study was performed to identify IIH patients with dural sinus stenosis treated with DVSS. Outcome measures included dural sinus pressure gradients, peripapillary retinal nerve fiber layer (RNFL) thickness using optical coherence tomography and improvement in symptoms.

RESULTS

Seventeen patients underwent DVSS. Average pre- and post-intervention pressure gradients were 23.06 and 1.18 mmHg, respectively (p < 0.0001). Sixteen (94%) noted improvement in headache, fourteen (82%) had visual improvement and all (100%) patients had improved main symptom. Of 11 patients with optical coherence tomography, 8 showed decreased RNFL thickness and 3 remained stable; furthermore, these 11 patients had improved vision with improved papilledema in 8, lack of pre-existing papilledema in 2 and stable, mild edema in 1 patient.

CONCLUSIONS

Our series of patients with dural sinus stenosis demonstrated improvement in vision and reduction in RNFL thickness. DVSS appears to be a useful treatment for IIH patients with dural sinus stenosis.

MRI in the Evaluation of Acute Visual Syndromes

Acute visual symptom emergencies occur commonly and present a challenge to both clinical and radiologic facets. Although most patients with visual complaints routinely require clinical evaluation with direct ophthalmologic evaluation, imaging is rarely necessary. However, there are highly morbid conditions where the prompt recognition and management of an acute visual syndrome (AVS) requires an astute physician to probe further. Suspicious symptomatology including abrupt visual loss, diplopia, ophthalmoplegia, and proptosis/exophthalmos require further investigation with advanced imaging modalities such as magnetic resonance imaging and magnetic resonance angiography. This review will discuss a variety of AVSs including orbital apex syndrome, cavernous sinus thrombosis, cavernous carotid fistula, acute hypertensive encephalopathy (posterior reversible encephalopathy syndrome), optic neuritis, pituitary apoplexy including hemorrhage into an existing adenoma, and idiopathic intracranial hypertension. A discussion of each entity will focus on the clinical presentation, management and prognosis when necessary and finally, neuroimaging with emphasis on magnetic resonance imaging. The primary purpose of this review is to provide an organized approach to the differential diagnosis and typical imaging patterns for AVSs. We have provided a template for radiologists and specialists to assist in early intervention in order to decrease morbidity and provide value-based patient care through imaging.

Papilledema: epidemiology, etiology, and clinical management

Papilledema is optic disc swelling due to high intracranial pressure. Possible conditions causing high intracranial pressure and papilledema include intracerebral mass lesions, cerebral hemorrhage, head trauma, meningitis, hydrocephalus, spinal cord lesions, impairment of cerebral sinus drainage, anomalies of the cranium, and idiopathic intracranial hypertension (IIH). Irrespective of the cause, visual loss is the feared morbidity of papilledema, and the main mechanism of optic nerve damage is intraneuronal ischemia secondary to axoplasmic flow stasis. Treatment is directed at correcting the underlying cause. In cases where there is no other identifiable cause for intracranial hypertension (ie, IIH) the available options include both medical and surgical modalities. Weight loss and diuretics remain the mainstays for treatment of IIH, and surgery is typically reserved for patients who fail, are intolerant to, or non-compliant with maximum medical therapy.

Incidence of vascular anomalies and variants associated with unilateral venous pulsatile tinnitus in 242 patients based on dual-phase contrast-enhanced computed tomography

BACKGROUND

A comprehensive assessment of various vascular anomalies and variants associated with venous pulsatile tinnitus (PT) by radiography is essential for therapeutic planning and improving the clinical outcome. This study evaluated the incidence of various vascular anomalies and variants on the PT side and determined whether these lesions occurred as multiple or single entities.

METHODS

The dual-phase contrast-enhanced computed tomography images of 242 patients with unilateral venous PT were retrospectively reviewed. The vascular anomalies and variants on the symptomatic and asymptomatic sides were analyzed, and the incidences of anomalies or variants on each side were compared. The number of anomalies and variants on the symptomatic side in each patient was calculated.

RESULTS

(1) A total 170 patients (170/242) had more than one anomaly or variant on the symptomatic side, and 58 patients (58/242) had a single lesion on tomography. (2) There was a statistically significant difference in the incidence of dehiscent sigmoid plate (P = 0.000), lateral sinus stenosis (P = 0.014), high jugular bulb (P = 0.000), sigmoid sinus diverticulum (P = 0.000), jugular bulb diverticulum (P = 0.000), dehiscent jugular bulb (P = 0.000), and a large emissary vein (P = 0.006) between the symptomatic and asymptomatic sides. (3) Dehiscent sigmoid plate (86.4%) was the most frequent lesion on the symptomatic side, followed by lateral sinus stenosis (55.8%), high jugular bulb (47.1%), sigmoid sinus diverticulum (34.3%), jugular bulb diverticulum (13.6%), dehiscent jugular bulb (13.6%), large emissary vein (4.1%), sinus thrombosis (1.2%), and petrosquamosal sinus (0.8%).

CONCLUSIONS

Various vascular anomalies and variants occur more frequently on the venous PT side. Preliminary findings suggest that venous PT patients may have multiple vascular anomalies or variants on the symptomatic side.

Intracranial hypotension and hypertension in children and adolescents

The specific aim of this review is to report the features of intracranial pressure changes [spontaneous intracranial hypotension (SIH) and idiopathic intracranial hypertension (IIH)] in children and adolescents, with emphasis on the presentation, diagnosis, and treatment modalities. Headache associated with intracranial pressure changes are relatively rare and less known in children and adolescents. SIH is a specific syndrome involving reduced intracranial pressure with orthostatic headache, frequently encountered connective tissue disorders, and a good prognosis with medical management, initial epidural blood patching, and sometimes further interventions may be required. IIH is an uncommon condition in children and different from the disease in adults, not only with respect to clinical features (likely to present with strabismus and stiff neck rather than headache or pulsatile tinnitus) but also different in outcome. Consequently, specific ICP changes of pediatric ages required specific attention both of exact diagnosis and entire management.

Intracranial hypertension and intracranial hypotension causing headache in the same patient

Intracranial hypertension and intracranial hypotension are on the opposite end of the intracranial pressure spectra. It is extremely uncommon for both to cause headache in the same patient within a span of several days. This report describes a young man with intracranial hypertension who developed a severe excruciating headache due to intracranial hypotension after a diagnostic lumbar puncture. It is paradoxical that lumbar puncture, which is supposed to be a treatment option for patients with idiopathic intracranial hypertension, leads to headache due to intracranial hypotension.