Superomedial Wall Research Articles

Endoscopic endonasal decompression for traumatic optic nerve injury: how I do it.

Endoscopic Endonasal Decompression for Traumatic Optic Nerve Injury has become an established endoscopic technique. However, Poor sphenoid sinus pneumatization often obscures landmarks, elevating the risk to vital neurovascular structures. By decompressing the orbital apex region and determining the contour of the optic nerve, sequential decompression of the medial wall, superomedial wall, and inferomedial wall of the optic canal. This surgical technique can gradually reveal the contour of the optic canal when the anatomical landmarks on the lateral wall of the sphenoid sinus are unclear, ensuring the surgery can be completed safely and effectively.

Supraorbital keyhole approach for paraclinoid aneurysms clipping: A case series with literature review.

Paraclinoid aneurysms (PcAs) are challenging aneurysms due to the complexity of their relation to the surrounding bony and neurovascular structures. Although over the past decade, their management strategy has shifted from transcranial to endovascular approaches; here, we try to revolve around a subcategory to which minimal invasive supraorbital keyhole (SOK) surgery is feasible depending on specific radiological criteria with a literature review. A group of unruptured PcAs was managed surgically, with a subset that was clipped through the SOK approach. They were selected by preoperative simulation images using 3D computed tomography (CT) angiography (CTA). We also conducted an extensive literature review based on a database available on PubMed and Google Scholar, the yielded cases from the literature review plus our cases were analyzed according to six parameters including their size, location, dome direction, need for clinoidectomy and proximal cervical control, and surgical outcome. From February 2009 to August 2022, 49 cases of unruptured PcAs were managed by clipping, and of these, four cases were clipped by the SOK approach, in addition, four cases were yielded through the literature review. The sizes of the PcAs ranged from 3 to 8 mm. Their location fluctuated from anterior to the superomedial wall and their domes pointed superiorly except for one which points posteriorly. Six of eight cases required anterior clinoidectomy, the outcome was uneventful. A subset of unruptured PcAs are amenable to SOK with criteria such as unruptured small aneurysm (<10 mm) and projected superiorly. These characteristics can be determined preoperatively using CTA.

Isolated Traumatic Bitemporal Hemianopia

Bitemporal hemianopia is a rare presentation following severe head injury, which causes a delay in detection of the visual symptoms. This is a case of traumatic bitemporal hemianopia in a 20-year-old gentleman after an alleged motorbike accident. He was intubated following a severe head injury. The ophthalmologic assessment was performed after he regained consciousness and complained of acute blurring of vision in bilateral eyes. The visual acuity was 2/60 on the right eye and 4/60 on the left eye. Bilateral eyes anterior and posterior segments examination were unremarkable. Confrontation visual field testing discovered bitemporal hemianopia. Plain computed tomography (CT) scan of the brain showed right frontal bone fracture extending to the right orbital roof, superomedial wall of the right orbit, bilateral lamina papyracea, ethmoidal air cells, roof and bilateral walls of sphenoid sinus. He was treated conservatively by the ophthalmology team. Subsequent follow-ups showed improvement of visual acuity which were 6/6 on the right eye and 6/6 on the left eye. Humphrey visual field test confirmed the persistence of bitemporal hemianopia. His good visual acuity does not correlate with the severity of the field defect. Therefore, surveillance for bitemporal scotoma is necessary for all head injuries with severe midline facial bone fractures.

Examination of the Topographical Anatomy and Fetal Development of the Tendinous Annulus of Zinn for a Common Origin of the Extraocular Recti.

The aim was to clarify the topographical anatomy of the common tendinous ring for the four rectus muscles in both adults and fetuses. We histologically examined the annular ligament for a common origin of the extraocular rectus muscles using 10 specimens from elderly individuals and 31 embryonic and fetal specimens. At 6 to 8 weeks, each rectus carried an independent long tendon, individually originating from the sphenoid. Notably, we found additional origins from the optic or oculomotor nerve sheath. At 12 to 15 weeks, the lateral, inferior, and medial recti muscles were united to provide a C-shaped musculofibrous mass that was separated from the superior rectus originating from the edge of the optic canal opening. Morphologic features at 31 to 38 weeks were almost the same as those at 12 to 15 weeks, but the long and thick common tendon of the three recti reached the sphenoid body in the parasellar area. In adults, a ring-like arrangement of the rectus muscles ended at a site 8.1 to 12.0 mm anterior to the optic canal opening and independent of the superior rectus origin, the lateral, inferior, and medial recti formed a C-shaped muscle mass. The united origins of the three recti changed to a fibrous band extending along the superomedial wall of the orbital fissure. Consequently, none of the specimens we examined exhibited an annular tendon representing a common origin of the four recti, suggesting that the common tendinous ring includes only medial, lateral, and inferior rectus muscles with the superior rectus taking its origin independently.

The course and the anatomo‐functional relationships of the optic radiation: a combined study with ‘post mortem’ dissections and ‘in vivo’ direct electrical mapping

Even if different dissection, tractographic and connectivity studies provided pure anatomical evidences about the optic radiations (ORs), descriptions of both the anatomical structure and the anatomo-functional relationships of the ORs with the adjacent bundles were not reported. We propose a detailed anatomical and functional study with 'post mortem' dissections and 'in vivo' direct electrical stimulation (DES) of the OR, demonstrating also the relationships with the adjacent eloquent bundles in a neurosurgical 'connectomic' perspective. Six human hemispheres (three left, three right) were dissected after a modified Klingler's preparation. The anatomy of the white matter was analysed according to systematic and topographical surgical perspectives. The anatomical results were correlated to the functional responses collected during three resections of tumours guided by cortico-subcortical DES during awake procedures. We identified two groups of fibres forming the OR. The superior component runs along the lateral wall of the occipital horn, the trigone and the supero-medial wall of the temporal horn. The inferior component covers inferiorly the occipital horn and the trigone, the lateral wall of the temporal horn and arches antero-medially to form the Meyer's Loop. The inferior fronto-occipital fascicle (IFOF) covers completely the superior OR along its entire course, as confirmed by the subcortical DES. The inferior longitudinal fascicle runs in a postero-anterior and inferior direction, covering the superior OR posteriorly and the inferior OR anteriorly. The IFOF identification allows the preservation of the superior OR in the anterior temporal resection, avoiding post-operative complete hemianopia. The identification of the superior OR during the posterior temporal, inferior parietal and occipital resections leads to the preservation of the IFOF and of the eloquent functions it subserves. The accurate knowledge of the OR course and the relationships with the adjacent bundles is crucial to optimize quality of resection and functional outcome.

The anterior cavernous sinus space

The anterior cavernous sinus space is the venous space anterior to the cavernous carotid artery. It is tetrahedral in shape with the anterior apex at the superior orbital fissure. The superomedial wall is formed by the base of the anterior clinoid process. The inferomedial wall is formed by the sphenoid bone. The lateral wall consists of two layers of dura with the oculomotor, trochlear, ophthalmic and abducens nerves in the inner layer. Medially, the posterior wall consists of the cavernous carotid artery. Laterally, it communicates with the lateral cavernous sinus space. Paraclinoid and carotid cave aneurysms may occupy this space and its microanatomy is important in the surgery of these aneurysms.

Case report: Leptomeningeal cyst of the orbit presenting with pulsatile exophthalmos

The case of a 64-year-old man who presented with unilateral pulsatile exophthalmos is described. A defect in the supero-medial wall of the orbit and an extraconal low density mass were demonstrated by orbital radiographs and CT. Positive contrast CT cisternography confirmed the diagnosis of a leptomeningeal cyst.