Unusual etiology of bilateral acute visual impairment: Optochiasmatic cavernoma haemorrhage

Optochiasmatic Cavernomas: Updated systematic review and proposal of a novel classification with surgical approaches

Cavernomas are histologically benign vascular malformations found at different sites in the brain. A rare site for such cavernomas, however, is the anterior optic pathway, comprising the optic nerve, chiasma, and optic tract-called optochiasmatic cavernomas (OCC). These lesions usually present with sudden onset or progressive vision loss, headache, and features mimicking pituitary apoplexy. In this paper, we describe a case of OCC operated at our center. We carry out an updated review of literature depicting cases of OCC, their clinical presentation, management, and postoperative complications. We also propose a novel classification system based on lesion location and further analyze these cavernoma types with respect to the surgical approach used and visual outcome. A 30-year-old lady had presented with a 3-week history of progressive bilateral vision loss and headache. Based on imaging, she was suspected to have a cavernous angioma of the chiasma and left optic tract. Due to progressive vision deterioration, the lesion was surgically excised using pterional craniotomy. Postoperatively, her visual symptoms improved, but she developed diabetes insipidus. Clinical and radiological follow-up has been done for 18 months after surgery. A total of 81 cases have been described in the literature, including the present case. Chiasmal apoplexy is the most common presentation. Surgical excision is the standard of care. Our analysis based on lesion location shows the most appropriate surgical approach to be used for each cavernoma type. Visual outcome correlates with the preoperative visual status. Visual outcome is good in patients presenting with acute chiasmal apoplexy, and when complete surgical excision is performed. The endonasal endoscopic approach was found to provide the best visual outcome. In addition to preoperative visual status, complete surgical excision predicts favorable visual outcomes in OCC. Our proposed classification system guides the appropriate surgical approach required for a particular location of the cavernoma.

An isolated cavernous malformation of the sixth cranial nerve: A case report and review of literature

Background

Isolated cavernous malformation (CM) of the abducens nerve has not been reported in the literature. Herein, the authors address the clinical importance of these lesions and review the reported cases of CM from 2014 to 2020.

Case Description

A 21-year-old man presented with binocular diplopia and headache from 2 months before his admission. The neurological examination revealed right-sided abducens nerve palsy. The brain MRI revealed an extra-axial pontomedullary lesion suggestive of a CM. The lesion was surgically removed. During the operation, the abducens nerve was resected considering the lesion could not be separated from the nerve and an anastomosis was performed using an interposition nerve graft and fibrin glue. Pathological examination of the resected lesion revealed that it was originated from within the nerve. The patient's condition improved in postoperative follow-ups.

Conclusion

Surgical resection of the cranial nerves CMs is appropriate when progressive neurological deficits are present. If the lesion is originated from within the nerve, we suggest resection of the involved nerve and performing anastomosis. Novel MRI sequences might help surgeons to be prepared for such cases and fibrin glue can serve as an appropriate tool to perform anastomosis when end-to-end sutures are impossible to perform.

Cavernous Malformations of the Optic Nerve and Optic Pathway: A Case Series and Systematic Review of the Literature

BACKGROUND

Although rare, cavernous malformations (CMs) of the optic nerve and anterior optic pathway (optic pathway cavernous malformations [OPCMs]) can occur, as described in several single case reports in the literature.

OBJECTIVE

To describe the technical aspects of microsurgical management of CMs of the optic pathway on the basis of an extensive single-center experience and review of the literature.

METHODS

A systematic literature review was performed to augment an earlier review, using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. In addition, an institutional database was searched for all patients undergoing surgical resection of OPCMs. Patient information, surgical technique, and clinical and radiographic outcomes were assessed.

RESULTS

Since the previous report, 14 CMs were resected at this institution or by the senior author at another institution. In addition, 34 cases were identified in the literature since the systematic review in 2015, including some earlier cases that were not discussed in the previous report. Most OPCMs were resected via pterional, orbital-pterional, and orbitozygomatic craniotomies. Visual outcomes were similar to those in earlier reports, with 70% of patients reporting stable to normal vision postoperatively.

CONCLUSION

OPCMs can occur throughout the anterior visual pathway and may cause significant symptoms. Surgery is feasible and should be considered for OPCMs presenting to a surface of the nerve. Favorable results can be obtained with resection, although optimal results are obtained with patients who present with milder symptoms without longstanding damage to the optic apparatus.