Case report: optic disc edema without hydrocephalus in acoustic neuroma

Navigating Uncharted Waters: Comparative Analysis of Clinical Progression and Outcomes in Vestibular Schwannoma Patients with Papilledema and without Hydrocephalus, Versus Those without Papilledema and Hydrocephalus: A Comprehensive Institutional Insight

BACKGROUND

Papilledema's association with hydrocephalus (HCP)-linked larger vestibular schwannoma (VS) is established but cases lacking concurrent HCP require further investigation.

METHODS

This retrospective comparative observational study, conducted from July 2018 to July 2023, examined 120 VS patients undergoing surgery. Patients were categorized into Group 1 (papilledema without HCP) and Group 2 (no papilledema or HCP), with comprehensive data analyzed.

RESULTS

In this study, Group 1 (14 patients with papilledema) and Group 2 (106 patients without papilledema or HCP) were compared. Group 1 was younger (mean age 27.21 ± 11.73 years) than Group 2 (mean age 54.66 ± 11.44 years). Both groups had similar symptom durations and tumor detection times. Group 1 had increased vascularity (P = 0.001), elevated cisterna magna protein levels (P = 0.001), and a higher incidence of neurofibromatosis 2 (P = 0.003). They also experienced longer surgeries (P = 0.001) and more blood loss (P = 0.001), leading to extended postoperative complications. Group 2 showed improved postsurgery visual outcomes (P = 0.001), better Glasgow Outcome Scores (P = 0.001), enhanced facial nerve preservation (P = 0.002), and improved hearing on follow-up (P = 0.003). Logistic regression analysis highlighted prolonged surgery duration (P = 0.057) and papilledema (P = 0.0001) as significant factors influencing visual improvement.

CONCLUSIONS

Patients with VS require preoperative fundoscopy evaluation due to potential visual loss and papilledema, even without HCP. Early treatment initiation enhances visual and hearing outcomes. Meticulous surgery is vital given the lesion's hypervascular nature and adherence to surrounding structures. Preoperative embolization may aid in preserving neurovascular structures. In developing countries with higher blindness rates, judicious noncontrast computed tomography brain evaluation is crucial for timely detection and treatment initiation of lesions like VS.

Systematic scoping review of papilledema in vestibular schwannoma without hydrocephalus

BACKGROUND

Vestibular schwannoma is a common pathology encountered by neurosurgeons worldwide. Often vestibular schwannoma presents with obstructive hydrocephalus. Papilledema is present in 8% of the patients with vestibular schwannoma, primarily due to obstructive hydrocephalus. Hyperproteinorrhachia is believed to be responsible for papilledema in the absence of hydrocephalus in vestibular schwannoma. However, there is a paucity of literature on the mechanism of papilledema in vestibular schwannoma patients with hydrocephalus.

OBJECTIVE

The aim of this study was to conduct a scoping review of scientific literature on papilledema in vestibular schwannoma patients without hydrocephalus.

METHODS

Design: This was a systematic scoping review and critical appraisal. Literature Search from PubMed was done following PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews) and Joanna Briggs Institute guidelines for conducting and reporting scoping reviews.

RESULTS

A total of seven studies, including eight patients, were identified for inclusion in the review. The studies were heterogeneous in terms of reporting for various variables. All the included studies were case reports, with the earliest publication in 1954 and the latest publication in 2020. The mean age of the patients in the included studies was 35 years, with a minimum age of 20 years and maximum age of 64 years. Approximately 62.5% were females, and 37.5% were males in the included study. Only three studies have studied cerebrospinal fluid (CSF) proteins levels in these patients.

CONCLUSIONS

There is paucity in literature and a lack of evidence to conclusively state hyperproteinorrhachia as an antecedent to the development of papilledema in vestibular schwannoma patients without hydrocephalus. Younger age and female gender are risk factors for developing papilledema in the absence of hydrocephalus in vestibular schwannoma patients. Brainstem compression due to the large size of vestibular schwannoma can still have a patent aqueduct of Sylvius and no obstruction to CSF flow. The development of papilledema in vestibular schwannoma is a complex interplay of multiple factors that must be studied comprehensively for complete understanding.

Preoperative Visual Impairment in Vestibular Schwannoma Patients: An Overlooked Entity of Developing World

Objective Visual impairment in vestibular schwannomas is an underreported entity. The plethora of literature focuses primarily on facial and hearing preservation. This study aims to describe our experience and find the possible reasons for visual impairment.

Materials and Methods This is a retrospective observational study. We evaluated 114 patients with vestibular schwannoma, operated during 2015 to 2020. Eight parameters were studied—age, gender, maximum tumor size, hydrocephalus, economic status, duration of symptoms, visual loss, and ease of access to the tertiary neurosurgical facility. JASP software (version 0.14.1, Amsterdam) was used for statistical analysis.

Results A total of 42/114 (36.84%) patients had a varying degree of impairment. Patients with impaired vision had significantly larger tumors (4.31 vs. 4.12 cm, p = 0.02), longer duration of symptoms (19.14 vs. 16.45 months, p = 0.02), hydrocephalus (p = 0.03), and were from remote areas (p = 0.009). In stepwise logistic regression analysis, longer duration of symptoms and difficult access to neurosurgical facility stand out as decisive factors for visual impairment. The follow-up data were available for 35/42 (83.33%) cases of visual impairment. Vision improved in 14/35 (40%) of cases. Vision improved in a significantly higher number of patients when a preoperative ventriculoperitoneal shunt was placed (p = 0.03).

Conclusion The visual handicap occurs in a significant number of patients with vestibular schwannoma. Delayed arrival at the neurosurgical facility due to difficult access appears to be the primary factor leading to blindness. Strengthening our healthcare systems in rural areas would go a long way in the timely detection and prevention of blindness in such cases.

Vision Deterioration and Hydrocephalus: Rare Presentations of Vestibular Schwannoma and Evolution of Management

Introduction The incidence of vestibular schwannoma is reported as 12 to 54 new cases per million per year, increasing over time. These patients usually present with unilateral sensorineural hearing loss, tinnitus, or vertigo. Rarely, these patients present with symptoms of hydrocephalus or vision changes.

Objective The study aimed to evaluate the surgical management of vestibular schwannoma at a single institution and to identify factors that may contribute to hydrocephalus, papilledema, and the need for pre-resection diversion of cerebrospinal fluid.

Patients and Methods A retrospective review examining the data of 203 patients with vestibular schwannoma managed with surgical resection from May 2008 to May 2020. We stratified patients into five different groups to analyze: tumors with a diameter of ≥40 mm, clinical evidence of hydrocephalus, and of papilledema, and patients who underwent pre-resection cerebrospinal fluid (CSF) diversion.

Results From May 2008 to May 2020, 203 patients were treated with surgical resection. Patients with tumors ≥40 mm were more likely to present with visual symptoms (p < 0.001). Presentation with hydrocephalus was associated with larger tumor size (p < 0.001) as well as concomitant visual symptoms and papilledema (p < 0.001). Patients with visual symptoms presented at a younger age (p = 0.002) and with larger tumors (p < 0.001).

Conclusion This case series highlights the rare presentation of vision changes and hydrocephalus in patients with vestibular schwannoma. We recommend urgent CSF diversion for patients with visual symptoms and hydrocephalus, followed by definitive resection. Further, vision may still deteriorate even after CSF diversion and tumor resection.

Neuro-Ophthalmic Complications of Vestibular Schwannoma Resection: Current Perspectives

Vestibular schwannomas (VSs), also called acoustic neuromas, are benign intracranial neoplasms of the vestibulocochlear (VIII) cranial nerve. Management options include “wait-and-scan,” stereotactic radiosurgery and surgical resection. Due to the proximity of the VIII nerve to the facial (VII) nerve in the cerebello-pontine angle, the VII nerve is particularly vulnerable to the effects of surgical resection. This can result in poor eye closure, lagophthalmos and resultant corneal exposure post VS resection. Additionally, compression from the tumor or resection can cause trigeminal (V) nerve damage and a desensate cornea. The combination of an exposed and desensate cornea puts the eye at risk of serious ocular complications including persistent epithelial defects, corneal ulceration, corneal vascularization, corneal melting and potential perforation. The abducens (VI) nerve can be affected by a large intracranial VS causing raised intracranial pressure (a false localizing sign) or as a result of damage to the VI nerve at the time of resection. Other types of neurogenic strabismus are rare and typically transient. Contralaterally beating nystagmus as a consequence of vestibular dysfunction is common post-operatively. This generally settles to pre-operative levels as central compensation occurs. Ipsilaterally beating nystagmus post-operatively should prompt investigation for post-operative cerebrovascular complications. Papilledema (and subsequent optic atrophy) can occur as a result of a large VS causing raised intracranial pressure. Where papilledema follows surgical resection of a VS, it can indicate that cerebral venous sinus thrombosis has occurred. Poor visual function following VS resection can result as a combination of all these potential complications and is more likely with larger tumors.

Papilledema secondary to vestibular schwannoma: An atypical case without intracranial hypertension

In most cases, vestibular schwannomas with papilledema are associated with intracranial hypertension secondary to hydrocephalus (obstructive or communicating). We describe the atypical case of a 39-years-old man who presented with bilateral papilledema revealing a vestibular schwannoma, but without hydrocephalus and with normal intracranial pressure. Ophtalmologic signs were completely resolved after tumor removal. The pathophysiological mechanism generally described to explain bilateral papilledema in such cases is tumor-induced hyperproteinorachia. However, in the absence of hydrocephalus or intracranial hypertension, this case raises the question of the mechanisms involved in the visual impairment related to vestibular schwannoma.

Vestibular Schwannoma Presenting with Bilateral Papilledema Without Hydrocephalus: Case Study

Bilateral papilledema secondary to obstructive or communicating hydrocephalus in patients with vestibular schwannomas is a known presentation; however, papilledema in the absence of hydrocephalus is rarely reported and its mechanism is poorly understood. We report a case of a 20-year-old woman presenting with visual deterioration and bilateral papilledema on fundoscopy. Magnetic resonance imaging (MRI) revealed a giant vestibular schwannoma with no sign of hydrocephalus. The only imaging evidence of increased pressure on preoperative imaging studies was seen on a T2-weighted MRI, where there was subtle dilatation of the arachnoid space of the optic sleeve. We presume that this patient developed papilledema by some mechanism not connected to hydrocephalus. In a young patient, papilledema may be a sign preceding hydrocephalus, or she may have had pseudotumor cerebri concomitant with her vestibular schwannoma. In either case, removal of the vestibular schwannoma solved the problem. She had complete visual recovery, irrespective of the mechanism.

Advanced Vestibular Schwannoma: A Case of Optic Disc Oedema without Hydrocephalus

A wide range of pathologies can cause papilloedema. Vestibular schwannoma is a benign and slow-growing tumour that causes symptoms and findings on ophthalmic examination when the diagnostic is delayed. The authors report a case of a 64-year-old male who presented with bilateral disc oedema secondary to a vestibular schwannoma grade 4. Obstructive hydrocephalus was not evident. The authors suggest that cerebrospinal fluid protein may have a role in the formation of optic disc oedema. A right suboccipital craniectomy was performed to remove the tumour, leading to secondary facial palsy.

The Pseudotumor Cerebri Syndrome: A Unifying Pathophysiological Concept for Patients with Isolated Intracranial Hypertension with Neither Mass Lesion Nor Ventriculomegaly

In 1991 we proposed that while the syndrome of isolated intracranial hypertension might have many definite and probable causes, it has nonetheless a single unifying pathophysiological mechanism: namely, impairment of cerebrospinal fluid (CSF) reabsorption. For that reason, we also proposed then that it is best described by a single, unifying, inclusive term, namely, pseudotumor cerebri syndrome. Although it appears that there is, as far as nomenclature is concerned, now international agreement, there is as yet no agreement on pathophysiology and classification. Herein we outline our views on these matters and give our reasons.

Large and giant vestibular schwannomas: does cisterna magna hyperproteinorrhachia influence visual status?

BACKGROUND

Hyperproteinorrhachia associated with vestibular schwannomas (VSs) may influence visual status independent of the effect caused by raised intracranial pressure. The role of cisterna magna CSF protein levels (CMCP) in determining visual outcome in patients with large to giant vestibular schwannomas (VSs) was prospectively investigated.

METHODS

The mean CMCP levels in VSs and control group; and, levels in VSs with or without visual deterioration were compared. Spearman's rank correlation coefficient tested for relationships between CMCP level with symptom duration and tumour volume (Kawamoto's method). Vision was regarded as normal when visual acuity was >6/18; and, deteriorated when it was between 6/18 and PL negative in the worse eye. Papilloedema (n = 26)/secondary optic atrophy (n = 6) and hydrocephalus (based on Evan's ratio, mild to moderate: n = 22; none: n = 18) were also recorded. The analysis of factors predicting diminished vision was done using logistic regression analysis (p < 0.05 significant).

FINDINGS

There was a significant difference (p < 0.001) in mean CMCP levels between VS (456.3 SD 213.6 mg/dl) and control groups (96.3 SD 74.3 mg/dl). The mean CMCP levels in the VS group were also markedly higher than the ventricular mean protein levels. The CMCP levels in patients with visual diminution (<6/18 to PL negative; n = 23) was 561.4 SD 186.9 mg/dl and those without visual loss (n = 17) was 314.2 SD 160.8 mg/dl (p < 0.001). Their grade of visual diminution had a positive correlation with mean CMCP levels (p < 0.001). There was a negative correlation between total duration of symptoms and CMCP levels (p < 0.015). Logistic regression analysis using five independent factors (symptom duration, papilloedema/secondary optic atrophy, tumour volume, hydrocephalus and mean CMCP level) revealed that only CMCP level had a significant association with visual diminution.

CONCLUSION

Elevated cisternal CSF proteins may play an important role in determining visual outcome in large to giant VSs. Ventricular CSF analysis is often unable confirm the presence of VS-associated cisternal hyperproteinorrhachia. High CMCP levels may influence decision-making while instituting a permanent CSF diversion for postoperative hydrocephalus or recalcitrant pseudomeningocoele.

[Bilateral papilledema: prospective study of fifty patients]

In this prospective study, we report fifty consecutive cases of bilateral papilledema without neurosurgical or obvious ophthalmologic etiology, referred to our institution between January 2005 and March 2007. Lumbar puncture with opening CSF pressure measurement distinguished two groups of patients: Group 1 (n=39) with and Group 2 (n=11) without intracranial hypertension. In Group 1, 9/39 patients presented secondary intracranial hypertension mainly due to cerebral venous thrombosis. In 30 patients, after complete investigations, a diagnosis of idiopathic intracranial hypertension was made: as commonly reported, patients were predominantly overweight (96.7% with body mass index>25kg/m2) young (mean age=27.6 years) and women (96.7%). Eleven patients with intracranial hypertension had no headaches. In Group 2, the most common diagnosis was bilateral non-arteritic anterior ischemic optic neuropathy, but rare causes have been identified.

Ganglioneuroma of the internal auditory canal: a case report

Ganglioneuroma is a rare, benign, slow-growing tumor thought to develop from cells of neural crest origin, even though hypotheses on the pathogenesis of that lesion differ. Ganglioneuromas, which do not release excessive catecholamine or steroid hormones, develop primarily in the posterior mediastinum and retroperitoneum. Because of their slow growth, many ganglioneuromas are large when they are diagnosed. In this case report, a 50-year-old woman with hearing loss is described. Magnetic resonance imaging revealed a mass (3 x 4 mm) in the internal auditory canal (IAC). The encapsulated tumor was entirely excised via the middle fossa approach. The results of histopathological examination indicated that the excised lesion was a ganglioneuroma. To our knowledge, this is the first report of a ganglioneuroma of the IAC. We suggest that ganglioneuroma be considered in the differential diagnosis of all tumors of the IAC.