Hemorrhagic schwannoma of the trochlear nerve: Case report and a review of the literature

Background

Schwannomas of the trochlear nerve with the absence of systemic neurofibromatosis are considerably uncommon, especially complicated by intra-tumoral hemorrhage. Due to the lack of typical clinical manifestations and imaging findings, a definite diagnosis of trochlear schwannomas before surgery is particularly difficult.

Case presentation

We report the case of a 64-year-old female patient who presented with a unilaterally intermittent headache of 2-month duration and without a remarkable neurological deficit at admission. Imaging studies revealed a well-demarcated cystic-solid lesion with mixed signals beside the brainstem and suprasellar cisterna. The patient underwent a surgical operation with total resection of the tumor by a subtemporal surgical approach. The tumor was intraoperatively found to originate from the trochlear nerve and was pathologically confirmed as a hemorrhagic schwannoma with cystic degeneration.

Conclusions

We describe this case in detail and conduct a concomitant survey of the literature, summarizing the clinical presentations, radiological features, surgical treatment, and the possible mechanisms of hemorrhage in relevance to trochlear nerve schwannoma.

Trochlear cistern of the cavernous sinus: an anatomical study using magnetic resonance imaging

PURPOSE

The present study aimed to explore the trochlear cistern (TC) of the cavernous sinus using magnetic resonance imaging (MRI).

METHODS

Following conventional MRI examination, a total of 73 patients underwent the constructive interference steady-state (CISS) sequence in thin-sliced coronal sections. Moreover, three injected cadaver heads were dissected.

RESULTS

In the cadaver specimens, the extent of the TC was difficult to identify on any dissected side. On the CISS images, the TC was identified in 98.6% on the right side and 94.5% on the left, while transmitting the trochlear nerve (TN) was identified in 83.6% on the right and 79.5% on the left. Most TNs were delineated as a single trunk, while duplication of the nerve was found in 3% of cases. The TC, commonly located inferior or inferolateral aspect of the oculomotor trigone. The size and extent of TC were highly variable. The TN location in the TC was also variable and was identified throughout the upper, middle, and lower parts of the TC. Moreover, relationships between the TC and Meckel's cave were highly variable.

CONCLUSIONS

TC shows morphological variability. The coronal CISS sequence is useful for exploring TC and TN in clinical practices.

Functional outcome after surgical treatment of cavernous malformation involving ocular motor cranial nerves: A systematic review

Cavernous malformations (CMs) of cranial nerves (CN) III, IV, and VI are extremely rare, and limited studies have assessed functional outcomes after treatment. This systematic review investigated the clinical features of CMs in ocular motor CNs, including the treatment results, and compared different surgical methods for functional preservation of ocular motor CNs. 'PubMed', 'SCOPUS', 'Web of Science', and 'Google Scholar' databases were searched to identify case reports and studies published between January 1980 and December 2018. This systematic review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Twenty-seven patients were identified (median age, 46 years; range, 3 months-71 years). CN III was involved in 17 patients (63.0%), CN IV in 8 (29.6%), and CN VI in 2 (7.4%). Treatments included gross total resection (GTR) and nerve transection in 6 patients (22.2%), GTR and nerve continuity preservation in 7 (25.9%), subtotal resection (STR) and nerve continuity preservation in 4 (14.8%), GTR and end-to-end anastomosis in 5 (18.5%), and conservative care in 3 (11.1%), while the treatment method for 2 (7.4%) patients has not been described in the literature. In 22 patients who underwent surgical treatment, functional changes included improvement in 9 patients (40.9%), no change in 10 (45.5%), and worsening symptoms in 3 (13.6%). Functional preservation was achieved in 12 (54.5%) of the 22 patients; the nerve continuity preservation method conferred a significant advantage for functional preservation compared with other surgical methods (p = 0.004). Functional preservation of ocular motor CNs can be achieved by nerve continuity preservation.

[Cavernous malformation of the optic nerve: clinical case and literature review]

INTRODUCTION

Cavernous malformation (cm) of the optic nerve is a rare condition It is clinically presented by the so-called chiasmal apoplexy. Microsurgical removal of cavernous malformation is the method of choice.

MATERIAL AND METHODS

Authors present a clinical case of the removal of cavernous malformation of the left optic nerve.

RESULTS

The presented case demonstrates the successful removal of the CM of the left optic nerve from the lateral supraorbital access. In the postoperative period, visual disorders did not worsen. Control MRI of the brain showed total removal of cavernoma.

CONCLUSION

Presented clinical case demonstrates the radical removal of CM of the optic nerve. Early and correct diagnosis makes it possible to adequately treat the patient and preserve his/her visual functions.

Acute Transient Oculomotor Nerve Palsy from Presumed Cavernous Angioma in an Infant

Cavernous angiomas of the cranial nerves are extremely rare, and those of the oculomotor (third) cranial nerve are rarer still, with no previous cases having been reported in the literature. We report herein the first case of a presumed cavernous angioma involving the subarachnoid portion of the left third nerve presenting as an acute left third nerve palsy in an infant. The child was followed without intervention and the palsy completely resolved. Given the poor functional results with attempted surgical excision and the potential for spontaneous improvement in oculomotor nerve function, it is reasonable to follow patients with these lesions without intervention.

Solitary Infiltrating Meningioma of the Trochlear Nerve: Case Report

We report the case of a solitary meningioma infiltrating the trochlear nerve, the first in a patient without a neurocutaneous disorder or cavernous sinus involvement. The patient presented with diplopia was found to have a focal enhancing mass encompassing the trochlear nerve. Following surgical resection, pathological examination showed meningioma infiltrating the nerve itself, demonstrated on the included pathology images. A review of the literature and discussion of meningiomas infiltrating cranial nerves are included.

Radiology and imaging for cavernous malformations

Cavernous malformations are low-flow vascular malformations that are histologically characterized by the lack of mural elements of mature vascular structures and intervening parenchymal neural tissue. They are often clinically quiescent, and may grow, bleed, and regress, but can also manifest clinically as neurologic deficits or seizures in the setting of an acute hemorrhage. The low-flow nature of cavernous malformations renders them inherently occult on cerebral angiography. Magnetic resonance imaging has become the mainstay imaging modality in evaluating cavernous malformations, producing characteristic imaging features that usually provide a straightforward diagnosis. Features on magnetic resonance imaging include a reticulated pattern of mixed hyper- and hypointensity on T1- and T2-weighted imaging, with a characteristic hypointense rim best appreciated on T2-weighted imaging or gradient-echo sequences. Contrast enhancement is useful for revealing coexisting developmental venous anomalies that are frequently associated with sporadic cavernous malformations, and may further support the diagnosis. Susceptibility-weighted imaging is highly sensitive for cavernous malformations and accompanying developmental venous anomalies, and is superior to gradient-echo sequences in screening for multifocal, familial cavernous malformations.

Inferior alveolar nerve hemangioma

A 14-year-old male presented with lower lip numbness and a slowly enlarging mandibular mass. Computed tomography demonstrated an expansile lesion centered in the marrow space of the left mandibular body, extending along the course of the inferior alveolar nerve (IAN), and expanding the mental foramen. Preoperative diagnosis was consistent with an IAN schwannoma. Surgical planning was performed using PROPLAN CMF software. The lesion was approached via a sagittal split osteotomy and excised en bloc with the IAN. Final pathology demonstrated a capillary hemangioma originating from the inferior alveolar nerve. Based on a detailed PubMed search, this is the first capillary hemangioma of the inferior alveolar nerve reported in the literature. Laryngoscope, 126:2168-2170, 2016.

Angiographically occult vascular malformation of the intracranial accessory nerve: case report

Angiographically occult cerebral vascular malformations (AOVMs) are usually found in the supratentorial brain parenchyma. Uncommonly, AOVMs can be found within the cavernous sinus or basal cisterns and can be associated with cranial nerves. AOVMs involving the intracranial segment of the spinal accessory nerve have not been described. A 46-year-old female patient presented with a history of episodic frontal headaches and episodes of nausea and dizziness, as well as gait instability progressing over 6 months prior to evaluation. Imaging revealed a well-circumscribed 3-cm extraaxial T1-weighted isointense and T2-weighted hyperintense contrast-enhancing mass centered in the region of the right lateral cerebellomedullary cistern. The patient underwent resection of the lesion. Although the intraoperative appearance was suggestive of a cavernous malformation, some histological findings were atypical, leading to the final diagnosis of vascular malformation, not otherwise specified. The patient's postoperative course was uneventful with complete resolution of symptoms. To the authors' knowledge, this is the first report of an AOVM involving the intracranial portion of the accessory nerve. For any AOVM located within the cerebellomedullary cistern or one suspected of involving a cranial nerve, the authors recommend including immunohistochemistry with primary antibody to neurofilament in the histopathology workup.

Surgical management of cavernous malformation of the optic nerve with canalicular extension

Background:

Cavernous malformations arising in a single optic nerves paring the chiasm (intracranial prechiasmatic optic nerve) and expanding into the optic canal are extremely rare lesions. Published series or case reports regarding the surgical removal of these vascular malformations within this specific location are scarce.

Case Description:

We present the first case to be published, of an intracranial optic nerve cavernous malformation with a contiguous canalicular component that was totally and successfully removed through a microsurgical pterional approach with excellent clinical outcome.

Conclusion:

This pathology should always be considered in the differential diagnosis of optic neuropathy and visual loss. Early detection and surgical proposal are mandatory, warranting the prevention of permanent damage to visual pathways. Radical resection is challenging, but usually curative and associated with favorable visual outcomes.

Intratemporal traumatic neuromas of the facial nerve: evidence for multiple etiologies

OBJECTIVE

To describe 2 patients with traumatic neuromas of the intratemporal facial nerve in the absence of trauma.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary care referral center.

PATIENTS

Patients included underwent resection of an intratemporal facial nerve mass. Upon pathologic evaluation, the patients were found to have traumatic neuromas of the facial nerve.

INTERVENTION(S)

Patients underwent resection of an intratemporal facial traumatic neuroma. Histopathologic evaluation was performed including an immunohistochemistry evaluation.

RESULTS

Two patients were identified with intratemporal facial nerve traumatic neuromas. The patients had no significant history of trauma or chronic inflammatory process. Pathologic evaluations, including immunohistochemistry, of the excised masses were consistent with traumatic neuromas. All tumors were noted to have a disorganized collection of axons and were not consistent with the expected diagnosis of schwannoma. Tumors involved the tympanic and vertical segments of the facial nerve. A cavernous angioma was found within one mass and is thought to be the etiology of neuroma formation.

CONCLUSION

Traumatic neuromas are possible in the intratemporal facial nerve in the absence of trauma. A cavernous angioma of the facial nerve is a newly described possible cause of traumatic neuroma formation.

Cavernous malformations isolated from cranial nerves: Unexpected diagnosis?

OBJECTIVES

Cranial nerves (CN) cavernous malformations (CMs) are lesions that are isolated from the CNs. The authors present three cases of CN CMs, for which MR was demonstrated to be critical for management, and surgical resection produced good outcomes for the patients. Surgical removal is the recommended course of action to restore or preserve neurological function and to eliminate the risk of future haemorrhage. However, the anatomical location and the complexity of nearby neural structures can make these lesions difficult to access and remove. In this study, the authors review the literature of reported cases of CN CMs to analyse the clinical and radiographic presentations, surgical approaches and neurological outcomes.

PATIENTS AND METHODS

A MEDLINE/Pub Med search was performed and revealed 86 cases of CN CMs. The authors report three additional cases in this study for a total of 89 cases. CMs affecting the optic nerve (CN II), oculomotor nerve (CN III), facial/vestibule-cochlear nerves (CN VII, CN VIII) have been described. The records of three patients were reviewed with respect to the lesion locations, symptoms, surgical approaches and therapeutic considerations. Clinical and radiological follow-up results are reported. Three patients (2 females, 1 male; age range 21-37 year) presented with three CN lesions. One lesion involved CN III, one lesion involved CN VII-CN VIII, and one involved CN II. The patient with the CN III lesion had a one-month history of mild right ptosis and diplopia. The patient with the CN VII-CN VIII lesion exhibited acute hearing loss and on the left and left facial paresis. The patient with the opticchiasmatic lesion presented with acute visual deterioration on the right and a left temporal field deficit in the left eye. Pterional and orbitozygomatic craniotomies were performed for the CN III lesion and the CN II lesion, and retrosigmoid craniotomy was performed for the cerebello-pontine angle lesion.

RESULTS

All patients experienced symptom improvement after surgery. On MR follow-up, recurrence was excluded in all patients.

CONCLUSIONS

CN CMs present with specific symptoms and require complex surgical techniques for resection. These lesions are frequently symptomatic, because of the complexity of the origin tissue. Symptomatic CN CMs should be resected microsurgically and completely when possible to prevent further losses of nerve function, improve function, avoid recurrence, and to eliminate the risk of future haemorrhages. The authors discuss the therapeutic options and the radiological features of these infrequent localisation of CMs. Specifically, the authors focus on the role of magnetic resonance imaging in the identification of these rare lesions.

Cranial nerve cavernous malformations causing trigeminal neuralgia and chiasmal apoplexy: Report of 2 cases and review of the literature

BACKGROUND

Cavernous malformations (CMs) confined to the cranial nerves (CN) are extremely rare lesions.

CASE DESCRIPTION

The authors report 2 cases of CMs, one involving the trigeminal nerve presenting with a 3 years history of a refractory right trigeminal neuralgia that was microsurgically resected by a retromastoid approach with resolution of the neuralgia; and another CM involving the chiasma with an abrupt onset of vision loss with acute intralesional bleeding that was removed through a right pterional approach with vision improvement.

CONCLUSION

Surgical resection is recommended in the context of progressive significant neurological deficit, emergency decompression as a result of recent hemorrhage for symptomatic relief or increase in size on serial magnetic resonance imaging (MRI).