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.

Volume Rendering Technique (VRT) for Planning and Learning Cranio-Vertebral Junction (CVJ) Surgeries: Technical Note.

AIM: To present the application of volume rendering technique (VRT) of computed tomography (CT) scan in cranio-vertebral junction (CVJ) surgeries. MATERIAL AND METHODS: The authors used VRT images of CT scan in patients of congenital CVJ anomalies who were subjected to various surgeries through midline posterior approach. The screw entry points and courses of vertebral arteries were identified in relation to various landmarks on the VRT images, preoperatively and intra-operatively. RESULTS: A total of 15 patients of CVJ anomalies, who underwent surgeries through midline posterior approach, formed the study group. The screw entry points and courses of the vertebral arteries could be effectively identified in the surgical fields. CONCLUSION: We conclude that VRT images are an inexpensive and user friendly tool to identify the screw insertion points in the surgeries of CVJ anomalies. They also help in identifying the course of the vertebral artery in the surgical field. On the whole, their use makes the surgery in this region, safer.

An Aberrant Line on CT Head: The Mendosal Suture.

A knowledge of variant anatomy is important in clinical practice. The skull bones have several normal anatomical variations, especially in the occipital bone. Accessory sutures have been described in newborns and young children. In this study, we discussed radiological findings of an accessory occipital suture in a 14-year-old child who had presented with mastoiditis and brain abscess. We further describe this "mendosal suture," and its pathophysiology and clinical implications. It is important to bear this entity in mind to avoid misdiagnosing this as a fracture. The use of CT scans and 3D CT using volume rendering technique (VRT) helps in detection and correct diagnosis.

Surgical Management of Extraocular Muscle Cysticercosis Causing Optic Foramen Syndrome.

Extraocular muscle cysticercosis usually presents with proptosis and restriction of eyeball movements. However, it can cause vision loss by compression of the optic nerve at the optic foramen in infrequent circumstances. We report a rare case with an unusual manifestation of ptosis, proptosis, lateral rectus palsy, and acute vision loss in the right eye. Magnetic resonance imaging was suggestive of cysticercal cyst. Emergency optic nerve decompression with cyst excision was done. Treatment of choice for extraocular muscle cysticercosis presenting with restriction of eyeball movements is mainly medical, consisting of albendazole and steroids. However, as this lesion rarely causes vision loss, indications of surgical decompression of optic nerve are not well defined. We recommend that early surgical management should be done along with medical treatment in cases of vision loss caused by extraocular muscle cysticercosis.