Optic Canal Research Articles

Surgical Outcome in Patients with Traumatic and Atraumatic Optic Neuropathy Following Endoscopic Optic Nerve Decompression.

Endoscopic optic nerve decompression is a highly effective and reliable approach for patients with select cases of optic neuropathy. It reduces the hydrostatic pressure and helps in relieving the compressive forces within the intracanalicular portion of the optic nerve consequently preserving and arresting the deterioration of vision. The advantages of the endoscopic approach over other procedures include preservation of olfaction, quick recovery, lack of external scars and less morbidity. The objective of the study isto assess the surgical outcome of endoscopic optic nerve decompression in patients with traumatic and atraumatic optic neuropathy. The case records of consequent patients attending ENT department with defective vision due to traumatic and atraumatic causes were reviewed. The outcome was measured in terms of improvement in visual acuity by log MAR scale. Among the 14 patients studied, 57% were females and the median age of presentation was 33 years. As compared to preoperative baseline visual acuity, the overall improvement was achieved in 11 patients, with an effective rate of 78.5% postoperatively. Patients presenting with no light perception and residual vision had significant improvement in visual acuity after surgery. Trans-nasal endoscopic surgery helps in decompressing the optic nerve with proper exposure of the orbital apex and optic canal without any intracranial or intra-orbital complications. Further, being a minimally invasive procedure has great advantage in cases of optic neuropathy.

UNILATERAL PAPILLEDEMA DUE TO IDIOPATHIC INTRACRANIAL HYPERTENSION: A CASE REPORT

Introduction: Papilledema is highly predicted and common to encounter in all causes of raised intracranial pressure including idiopathic intracranial hypertension; it is usually bilateral and symmetrical. Unilateral and asymmetrical papilledema is considered highly atypical and a rarity of presentation, posing significant diagnostic challenge to the poorly understood pathological phenomenon of IIH.Case: We report a 40-year-old African female with idiopathic intracranial hypertension who fully fulfills the Modified Danddy Criteria; presenting with unilateral papilledema, with Left eye fundoscopic examination showing extensively hyperemic and swollen optic disc with an associated tortuously engorged retinal vein. Brain imaging via MRI revealed partial empty sella, bilateral prominent fluid signal projection that is more evident in the left optic nerve sheath and a prominent meckel’s cave on the left side measuring (6.1 mm) in the transverse diameter. MRA concluded an attenuated most lateral side of the left transverse sinus. Lumbar puncture was attempted and revealed an opening pressure of (45 cmH2O), and otherwise normal CSF cytology and chemical composition. Significant symptomatic relief was depicted upon lumbar puncture.Discussion: papilledema is universally encountered as a bilateral and symmetrical phenomenon; thus, presentation of IIH with unilateral papilledema has been under extensive research recently in attempts to contemplate the exact pathophysiology. Amongst many other proposed theories, we endorse the variation of the optic canal diameter as a potential mechanism for asymmetry of papilledema in IIH. As larger optic canal diameter is postulated to be associated with higher CSF pressure force transduction with subsequent optic nerve damage.Conclusion: Unilateral and asymmetrical papilledema is considered substantially unique and anecdotal rarities of presentation of IIH; posing a significant diagnostic troublesome and dilemma. Physicians should be aware and highly vigilant of such deviations of usual presentations to avoid consequential diagnostic and management adverse outcomes and unwanted complications.

Craniofacial Fibrous Dysplasia in Fronto-Orbital Region: A Single-Center Retrospective Study of 38 Cases

This study presents the clinical characteristics, imaging manifestations, and surgical experience in 38 patients diagnosed with craniofacial fibrous dysplasia in fronto-orbital region (foFD). We retrospectively analyzed the clinical data from 38 patients who had surgery for foFD. The surgical procedure typically involved extensive tumor removal, followed by immediate reconstruction of the frontal bone and orbit using synthetic materials. Additionally, 9 patients underwent simultaneous microscopic decompression of the optic canal. Common clinical manifestations included progressive fronto-orbital bone deformity (35), proptosis (28), orbital dystopia (21), and visual impairment (9). The disease primarily affecting the frontal bone (38), the sphenoid bone (28), and the ethmoid bone (24). The optic canal was involved in 9 patients with functional impairment. Computed tomography scans in all 38 cases revealed satisfactory repair material positioning and complete resolution of frontal deformities. Among the 9 patients who underwent optic canal decompression, 7 experienced partial recovery of visual acuity after surgery. In the surgical treatment of foFD, it is crucial to achieve maximal bone resection and repair skull defects, while decompressing the optic canal can provide significant benefits for patients with decreased visual function preoperatively. The use of preformed artificial materials offers advantages in aesthetic restoration after lesion excision.

NCMP-17. IMPROVEMENT IN CRANIAL NEUROPATHIES FOLLOWING STEREOTACTIC RADIOTHERAPY ALONE FOR SKULL BASE MENINGIOMAS

Abstract Cranial neuropathies are a common presenting symptom in skull base meningiomas. Many of these tumors are not amenable to surgical resection; for these patients, stereotactic radiotherapy (SRT) is a viable option. Our study sought to investigate the efficacy of SRT for improving cranial neuropathies and identify predictors that portend favorable response. A single-institution retrospective analysis was performed for patients with skull base meningiomas causing cranial neuropathies who received SRT as sole treatment from 2001 to 2021. Clinical variables were collected and analyzed for predictors of improvement. Subgroup analysis for each type of cranial neuropathy was also performed. Overall 101 patients were included, of which 51 (50.4%) had an improvement in cranial neuropathy following SRT. There was no difference in gender or age between patients with and without improvement. The most common tumor location was cerebellopontine angle (n=38), followed by cavernous sinus (n=27) and optic canal (n=25). Cranial nerve II was most frequently affected (n=34), followed by VI (n=28) and V (n=27). There was no significant difference in tumor volume, radiation dose, location, or specific cranial nerve affected between patients with and without improvement. Median time to improvement was 8 months (IQR 3-15). In subgroup analysis, patients with optic neuropathy who experienced improvement after SRT were significantly younger (50.7 vs. 60.1 years, p=0.03), while patients with trigeminal neuropathy who experienced improvement were significantly older (69.6 vs. 58.7 years, p=0.03). For patients with extraocular movement neuropathies or vestibulocochlear dysfunction, there were no significant factors associated with improvement. Half of patients with cranial neuropathy from skull base meningiomas experience symptomatic improvement following sole SRT. Age may play a role in predicting improvement, with younger patients more likely to have improved vision and older patients more likely to experience improvement in trigeminal neuropathy.

Optic Canal Size is an Indicator for the Accessory Optic Canal: Applications for Anterior Clinoidectomy

BackgroundThe ophthalmic artery normally travels with the optic nerve through the optic canal. However, sometimes, the ophthalmic artery travels through a foramen within the optic strut named an accessory optic canal, double optic canal, or ophthalmic canal. This variant puts individuals at an increased risk for blindness or death during anterior clinoidectomy due to unforeseen hemorrhage of the ophthalmic artery or internal carotid artery when the optic strut is separated from the body of the sphenoid bone. Several features make the accessory optic canal difficult to recognize on imaging: its variant nature, small size, and ability to masquerade as a caroticoclinoid foramen or a pneumatized sphenoidal structure. Hence, improved methods of presurgical identification are warranted. The aim of this study was to assess the size and shape of the optic canal, with and without a concomitant accessory optic canal, to determine whether measurement of the optic canal may provide useful information regarding the presence of an accessory optic canal. MethodsIn 191 dry crania, optic canals with and without concomitant accessory optic canals were assessed for the following parameters: canal area, canal perimeter, circularity, solidity, the axes and aspect ratio of a best fit ellipse, and roundness. ResultsNormal optic canals were found to have a larger area (p=0.036), perimeter (p=0.043), and minor axis of a best fit ellipse (p=0.031) than the optic canals that occurred alongside accessory optic canals. ConclusionsAsymmetry in optic canal size can help indicate the presence of a unilateral accessory optic canal prior to surgery.

Prechiasmatic Transection of the Unilateral Dodge Class Ⅰ Optic Pathway Glioma without Neurofibromatosis Type 1: Technical Description and Clinical Prognosis

For unilateral Dodge Class Ⅰ optic pathway glioma (OPG-uDCⅠ) without neurofibromatosis type 1, unilateral isolated optic nerve gliomas before the optic chiasm have been confirmed to possibly cause visual deterioration and poor prognosis. For this type of highly selective localized tumor, we explored surgery as the only treatment method. This article retrospectively analyzed and summarized the clinical data of this case series, with the aim of exploring the main technical details and clinical prognosis. Included were patients with OPG-uDCⅠ without neurofibromatosis type 1 and experiencing vision loss on the affected side. The fronto-orbital approach was used, which was mainly divided into 3 parts: intraorbital, optic canal, and intracranial. All patients underwent prechiasmatic resection without any adjuvant treatments. The follow-up period was 3months after surgery, and magnetic resonance imaging and contralateral visual acuity were reviewed annually after surgery. All OPG-uDCⅠ cases were completely removed without any adjuvant treatments, and there was no recurrence during the follow-up period. Pathological results showed that, except for 1 adult patient with pilomyxoid astrocytoma (World Health Organization grade Ⅱ), the others all had pilocytic astrocytoma (World Health Organization grade Ⅰ). Five patients experienced transient ptosis, and all recovered 3months after surgery. For OPG-uDCⅠ without neurofibromatosis type 1, radical prechiasmatic resection of the tumor is possible, without the need for postoperative radiotherapy and chemotherapy.

THU101 A Challenging Case Of Recurrent Suprasellar Epidermoid Cyst With Visual Field Deficits

Abstract Disclosure: S. Ahsun: None. A. Atri: None. R. Bhat: None. C. eaton: None. N. Blocher: None. A challenging case of recurrent suprasellar epidermoid cyst with visual field deficits. Introduction: Intracranial epidermoid cysts account for approximately 1% of all intracranial tumors. The most common location of occurrence is cerebellopontine angle. Suprasellar region is the second most common location. We present a case for suprasellar epidermoid cyst with visual field deficits. Case Presentation: A 52 y/o female presented to an ophthalmologist for blurring of vision and was found to have bitemporal hemianopia. MRI of the brain showed a large suprasellar mass of 6.9x4.2x3.3 cm with extension into the surrounding structures. A portion of the cyst wall was hemorrhagic. There was significant mass-effect on the optic chiasm and bilateral optic tracts. Patient underwent elective craniotomy with left frontotemporal approach. A characteristic pearly wide epidermoid capsule was visualized through the oculomotor triangle. The optic nerve was noted to be quite distorted in its course, exiting from the optic canal and being pushed superiorly by the epidermoid tumor. Accessible tumor capsule was resected, however due to the dense adhesions of the epidermoid cyst to the surrounding vasculature and the optic nerves, complete resection was not attempted. Postoperatively, patient developed right-sided hemiparesis due to an acute infarct. Patient also developed some dementia, hyperphagia and aggressive behavior following her surgery. She started her rehabilitation therapy but had persistent dementia and cognitive decline. Repeat vision testing showed right superior homonymous hemianopia. MRI of the brain a year after the initial surgery showed growth of the residual cyst and some obstructive hydrocephalus but without any symptoms. She underwent a second debulking procedure that was successful with complete excision of the residual tumor but the patient had delayed recovery. She subsequently underwent tracheostomy and PEG tube placement and was transferred to the rehabilitation facility. She is now awake but still nonverbal. Patient also developed panhypopituitarism and is currently on the replacement for cortisol and thyroid hormone. She is also on DDAVP for her diabetes insipidus which seems to be permanent in her case. Conclusion: This case highlights some important facts: 1. Epidermoid cysts are challenging from the management standpoint. Only 50-80% can be resected completely. Incomplete removal increases the chances for recurrence which are variable at 1-54%. 2. Even in cases of recurrent growth repeat surgery should only be performed if patient has significant symptoms from the tumor. 3.As per the literature patients with adjuvant radiotherapy have improved outcomes. As in our case radiotherapy should have been considered in the setting of recurrence of the tumor. 4.Endoscopic endonasal approach is a new modality that has shown a very low rate of complications after resection. Presentation: Thursday, June 15, 2023

THU100 Case Of A Large Suprasellar-clival Mass: Prolactinoma Vs Paraganglioma

Abstract Disclosure: L.N. Madera Marin: None. Y. Rivera-Nieves: None. M.A. Ortiz-Rivera: None. A. Rosado-Burgos: None. L. El Musa Penna: None. W. Medina-Torres: None. L. Sepulveda-Garcia: None. M. Ramirez: None. L.A. Gonzalez-Rodriguez: None. M. Alvarado: None. N. Canales: None. Introduction Prolactin secreting adenomas comprise 30-40% of all pituitary adenomas. Generally, serum prolactin levels correlate with tumor size. Giant prolactinomas measure >4 cm, most have mass related clinical effects. Even large masses respond to cabergoline. Some may require surgical intervention. We present a case of a large pituitary mass associated with elevated prolactin levels, but with an interesting histopathologic analysis. Patient Description 30 y/o male patient with new onset decreased peripheral vision. Retinologist evaluation showed no abnormalities. Laboratories done by PCP found with altered thyroid function tests, but no treatment offered at the time. Two months later, the patient complained of worsening peripheral vision and was found with a left dilated pupil. A head CT scan was performed that showed a large brain mass. Admitted for urgent neurosurgery evaluation and high dose dexamethasone was initiated. ROS was remarkable for weight gain over the past year, and decreased morning erections, although denied decreased libido or erectile dysfunction. MRI showed an infiltrative skull base tumor extending from the clivus to the parasellar area encasing the left cavernous segment of the internal carotid artery with expansion of the sella obliterating the pituitary gland, and extension into the left optic canal. Pre-operative laboratories: Prolactin >877 ng/ml (2-17ng/ml), Cortisol 1.80 mcg/dL (4-22 mcg/dL), TSH 1.45 uIU/ml (0.4-4.0 uIU/ml), Sodium 142mMol/L (135-145mMol/L). Patient underwent left pterional craniotomy. Initial intra-operative pathology: “Positive for Neoplasia”. Post-operative laboratories: Prolactin >877 ng/ml, TSH 0.229 uIU/ml, FSH <0.30 mIU/ml (1.2-7.8 mIU/ml), and LH 0.16 mIU/ml (1.5-9.3 mIU/ml). Case Outcomes/Discussion Central hypothyroidism and hypogonadism confirmed, secondary hypocortisolism could not be assessed due to emergent corticosteroid infusion upon admission. A presumptive diagnosis of a giant prolactinoma was made for which cabergoline therapy was initiated. Final pathologic diagnosis revealed a paraganglioma. Urine fractionated metanephrines and catecholamines were normal. Immunostaining for prolactin requested. Paragangliomas arise from neuroendocrine cells, from either sympathetic or parasympathetic ganglia and can be solitary or multiple. Skull base and neck paragangliomas are usually benign while ∼20% of abdominal paragangliomas (sympathetic) are malignant. Anterior skull base paragangliomas are predominantly located in the sella and are rare but have been described in the literature. Very rare cases of pheochromocytomas or paragangliomas associated to pituitary adenomas have been reported. It has been named as the three P association, thought to be related to succinate dehydrogenase B and D mutations. Moreover, there are no cases in the literature of paragangliomas secreting prolactin. Presentation: Thursday, June 15, 2023

NUT carcinoma presenting as retrobulbar optic neuropathy: A lethal masquerade!

A case of a 15-year-old girl with sudden vision loss left eye, left relative afferent pupillary defect, and normal fundus both eyes. Magnetic resonance imaging (MRI) brain and orbits showed a heterogeneous enhancing mass lesion in the left posterior ethmoid sinus with bony invasion and crowding of the optic canal. She underwent left optic nerve decompression with removal of the lesion and was started on systemic steroids. Biopsy was suggestive of NUT carcinoma (NC) and immunohistochemistry (IHC) confirmed the same. Despite chemotherapy, the tumor progressed rapidly in six months invading the left orbit, extending to right side of the midline and left anterior cranial fossa, with subsequent complete loss of vision of right eye also. She eventually underwent a globe sparing orbital exenteration with anterior cranial base resection along with postoperative radiotherapy. A month later, patient developed extensive skeletal and hepatic metastasis and succumbed to the disease; 11 months after the initial diagnosis.

The virtual brain endocast of Trogosus (Mammalia, Tillodontia) and its relevance in understanding the extinction of archaic placental mammals.

After successfully diversifying during the Paleocene, the descendants of the first wave of mammals that survived the end-Cretaceous mass extinction waned throughout the Eocene. Competition with modern crown clades and intense climate fluctuations may have been part of the factors leading to the extinction of these archaic groups. Why these taxa went extinct has rarely been studied from the perspective of the nervous system. Here, we describe the first virtual endocasts for the archaic order Tillodontia. Three species from the middle Eocene of North America were analyzed: Trogosus hillsii, Trogosus grangeri, and Trogosus castoridens. We made morphological comparisons with the plaster endocast of another tillodont, Tillodon fodiens, as well as groups potentially related to Tillodontia: Pantodonta, Arctocyonidae, and Cimolesta. Trogosus shows very little inter-specific variation with the only potential difference being related to the fusion of the optic canal and sphenorbital fissure. Many ancestral features are displayed by Trogosus, including an exposed midbrain, small neocortex, orbitotemporal canal ventral to rhinal fissure, and a broad circular fissure. Potential characteristics that could unite Tillodontia with Pantodonta, and Arctocyonidae are the posterior position of cranial nerve V3 exit in relation to the cerebrum and the low degree of development of the subarcuate fossa. The presence of large olfactory bulbs and a relatively small neocortex are consistent with a terrestrial lifestyle. A relatively small neocortex may have put Trogosus at risk when competing with artiodactyls for potentially similar resources and avoiding predation from archaic carnivorans, both of which are known to have had larger relative brain and neocortex sizes in the Eocene. These factors may have possibly exacerbated the extinction of Tillodontia, which showed highly specialized morphologies despite the increase in climate fluctuations throughout the Eocene, before disappearing during the middle Eocene.

Visual Outcomes and Surgical Approach Selection Focusing on Active Optic Canal Decompression and Maximum Safe Resection for Suprasellar Meningiomas.

The goal of treating patients with suprasellar meningioma is improving or preserving visual function while achieving long-term tumor control. We retrospectively examined patient and tumor characteristics and surgical and visual outcomes in 30 patients with a suprasellar meningioma who underwent resection via an endoscopic endonasal (15 patients), sub-frontal (8 patients), or anterior interhemispheric (7 patients) approach. Approach selection was based on the presence of optic canal invasion, vascular encasement, and tumor extension. Optic canal decompression and exploration were performed as key surgical procedures. Simpson grade 1 to 3 resection was achieved in 80% of cases. Among the 26 patients with pre-existing visual dysfunction, vision at discharge improved in 18 patients (69.2%), remained unchanged in six (23.1%), and deteriorated in two (7.7%). Further gradual visual recovery and/or maintenance of useful vision were also observed during follow-up. We propose an algorithm for selecting the appropriate surgical approach to a suprasellar meningioma based on preoperative radiologic tumor characteristics. The algorithm focuses on effective optic canal decompression and maximum safe resection, possibly contributing to favorable visual outcomes.

Management of Proptosis in a Case of Sphenoid-Orbital Meningioma

Sphenoid-orbital meningiomas (SOMs) are difficult to completely resect because they involve the sphenoid wing, orbit, and cavernous sinus. As the tumor invades the optic canal, SOMs frequently present with visual deficits. The authors of this case report dealt with the case of a 65-year-old male patient who had right-sided proptosis. We diagnosed the patient, and his MRI revealed of him having SOM. The surgical approach was determined by the tumor's placement in the orbit and cranial cavity and its connections to the optic canal and optic nerve axis. Tumor was removed successfully by surgery. The patient retained a proptosis of less than 4 mm during the follow-up period. The visual acuity, visual field, and ocular fundus were examined during the follow-up. SOMs are notoriously difficult to treat surgically. The primary goal of surgery in symptomatic individuals with SOMs is to slow down the tumor's progression. Longer periods of post-operative follow-up is recommended to observe long-term results. Bang. J Neurosurgery 2022; 12(1): 65-68

Myopia: Histology, clinical features, and potential implications for the etiology of axial elongation.

Myopic axial elongation is associated with various non-pathological changes. These include a decrease in photoreceptor cell and retinal pigment epithelium (RPE) cell density and retinal layer thickness, mainly in the retro-equatorial to equatorial regions; choroidal and scleral thinning pronounced at the posterior pole and least marked at the ora serrata; and a shift in Bruch's membrane opening (BMO) occurring in moderately myopic eyes and typically in the temporal/inferior direction. The BMO shift leads to an overhang of Bruch's membrane (BM) into the nasal intrapapillary compartment and BM absence in the temporal region (i.e., parapapillary gamma zone), optic disc ovalization due to shortening of the ophthalmoscopically visible horizontal disc diameter, fovea-optic disc distance elongation, reduction in angle kappa, and straightening/stretching of the papillomacular retinal blood vessels and retinal nerve fibers. Highly myopic eyes additionally show an enlargement of all layers of the optic nerve canal, elongation and thinning of the lamina cribrosa, peripapillary scleral flange (i.e., parapapillary delta zone) and peripapillary choroidal border tissue, and development of circular parapapillary beta, gamma, and delta zone. Pathological features of high myopia include development of macular linear RPE defects (lacquer cracks), which widen to round RPE defects (patchy atrophies) with central BM defects, macular neovascularization, myopic macular retinoschisis, and glaucomatous/glaucoma-like and non-glaucomatous optic neuropathy. BM thickness is unrelated to axial length. Including the change in eye shape from a sphere in emmetropia to a prolate (rotational) ellipsoid in myopia, the features may be explained by a primary BM enlargement in the retro-equatorial/equatorial region leading to axial elongation.

Anatomical identification of supraseptal posterior ethmoid cells and its significance for endoscopic sinus surgery.

To investigate the anatomical imaging characteristics of supraseptal posterior ethmoid cells (SPEC). Paranasal sinus computed tomography scans of 153 inpatients from February 2019 to September 2021 were reviewed, and the anatomical characteristics of SPEC in the scans were collected. Supraseptal posterior ethmoid cells are posterior ethmoid (PE) cells extending medially and superiorly to the posterior superior of the nasal septum and into the sphenoid body but not close to the optic canal. The SPEC, Onodi cell, and sphenoidal sinus (SS) may appear in the posterior superior of the nasal septum, but the occurrence rate of the SPEC (5.88%; 9/153 cases) was significantly lower than that of the SS (22.88%) and Onodi cell (21.57%). The anterior SPEC is adjacent to the cribriform plate, the perpendicular plate of the ethmoid bone and the posterior ethmoidal artery (PEA). The posterior SPEC is adjacent to the SS and PE (6/9 cases), the SS and Onodi cell (2/9 cases) or the PE only (1/9 cases). The SPEC is a rare pneumatization that occurs in the posterior superior area of the nasal septum. Care should be taken to protect the skull base, cribriform plate and PEA when opening the SPEC during endoscopic sinus surgery.

Optic foramen location on computed tomography.

This study aimed to identify the location of the optic foramen in relation to the anterior sphenoid sinus wall, which is essential information for surgeons in planning and performing endoscopic transnasal surgery. Computed tomography scans of 200 orbits from 100 adult patients with no abnormalities were examined. The results included the location of the optic foramen in relation to the anterior sphenoid sinus wall and the distance between them, as well as the distance from the optic foramen and the anterior sphenoid sinus wall to the carotid prominence in the posterior sphenoid sinus. The optic foramen was anterior to the anterior sphenoid sinus wall in 48.5% of orbits, and posterior in the remaining 51.5%. The mean distance from the optic foramen to the anterior sphenoid sinus wall was 3.82 ± 1.25 mm. The mean distances from the optic foramen and the anterior sphenoid sinus wall to the carotid prominence were 7.67 ± 1.73 and 7.95 ± 2.53 mm, respectively. The optic foramen was anterior to the anterior wall of the sphenoid sinus in approximately half of the orbits examined in this study, and posterior in the remaining half. The mean distance from the optic foramen to the anterior sphenoid sinus wall of the sphenoid sinus was 3.82 ± 1.25 mm.

Effect of Optic Canal Opening on Postoperative Visual Acuity in Patients with Tuberculum Sellae Meningiomas.

Tuberculum sellae meningiomas (TSMs) account for 5 to 10% of all intracranial meningiomas. They typically invade the optic canal and displace the optic nerve upward and laterally. The transcranial approach has been the standard surgical approach, while the transsphenoidal approach has been proposed for its minimally invasive nature; however, some reservations concerning this approach remain. From January 2000 to December 2018, a total of 97 patients who were diagnosed with TSM with invasion of the optic canal were enrolled and underwent microsurgery for tumor removal with optic canal opening. A retrospective analysis was performed on the effect of optic canal opening on postoperative visual acuity improvement. The median follow-up was 17.4 months (range: 3-86 months). Among the 97 patients with TSM involving the optic canal, optic canal invasion was seen on preoperative imaging in 73 patients and during intraoperative exploration in all patients. In total, 87/97 patients (89.7%) underwent optic canal opening to remove tumors involving the optic canal, and the rate of total macroscopic resection of tumors invading the optic canal was 100%. Among the 10 patients who did not undergo optic canal opening, the rate of total resection of tumors involving the optic canal was 80% (8/10, p < 0.001). There were no deaths or serious complications. The postoperative visual acuity improvement rate was 64.4%, 23.7% maintained the preoperative level, and the visual acuity deteriorated 11.9%. Intraoperative optic canal opening is the key to total resection of TSMs involving the optic canal and improving postoperative visual acuity.

Probable Posterior Ischemic Optic Neuropathy Associated with Acute Fungal Sinusitis

Purpose: We report a case of probable posterior ischemic optic neuropathy in a patient with acute fungal sinusitis.Case Summary: An 81-year-old male patient presented with sudden-onset visual loss in his left eye 3 weeks prior to presentation. His best corrected visual acuity was 0.6 in his right eye and light perception in his left eye. Pupillary size was 3 mm in both eyes, and a relative afferent pupillary defect was detected in his left eye. In fundus examination, diabetic retinopathy was found, and cup/disc ratios were increased in both eyes, but disc swelling and hemorrhage were not observed. Fluorescein angiography did not indicate filling delay, defects, or leakage of discs in either eye. Magnetic resonance imaging of the brain revealed multi-sinusitis in the sphenoid, ethmoid, and frontal sinuses. No bony defects or erosion were found around the optic canal or orbital apex during endoscopic surgery; however, histological examination revealed aspergillosis. The patient was diagnosed with posterior ischemic optic neuropathy caused by acute fungal sinusitis.Conclusions: When elderly patients with uncontrolled diabetes experience sudden visual disturbances without ocular pain, posterior ischemic optic neuropathy with fungal sinusitis should be considered as a differential diagnosis. Immediate imaging studies and appropriate treatment should be performed.

Optic canal: a CT-based morphometric study in north Indian population

BackgroundLesser wing of sphenoid joins the body of sphenoid by two roots which are separated by the optic canal. Optic canal is a communicating channel between orbit and middle cranial fossa, forming a passage for the ophthalmic artery and optic nerve. Considering the delicate neurovascular structure that traverses the narrow confines of the optic canal, knowledge of the morphometry, anatomical variations of this canal and their relations becomes an important part of diagnostic medicine and surgical management.ObjectiveThe aim of the study was to conduct morphometric analysis and document variations of optic canal in north Indian population and study its sexual dimorphism.Material and MethodType of Study Cross-sectional study. Sample size 200 Computerized tomography head axial section scans from picture archiving and communication system. The computer-assisted measurements of optic canal parameters were obtained on both right and left sides. Statistical analysis Unpaired t-test, paired t-test and ANOVA were applied.ResultOptic canal of 110 males, 90 females were examined. The overall cranial opening diameter, orbital opening diameter and length of optic canal in males were 4.34 ± 0.74, 3.17 ± 0.58 and 9.81 ± 1.62 and in females they were 3.99 ± 0.71, 2.97 ± 0.59 and 9.38 ± 2.02 respectively.ConclusionSignificant gender difference is seen in cranial and orbital opening diameter, and distance from midsagittal plane. No statistical significant difference is observed in right and left side parameters. A thorough knowledge of the normal dimensions of optic canal is important for evaluation and management of cases of optic nerve decompression.

A Six-Surface System to Describe Anatomy of Anterior Clinoid Process and Its Application in Anterior Clinoidectomy and Resection of Paraclinoid Meningioma

The anterior clinoid process (ACP) is surrounded by nerves and vessels that, together, constitute an intricate anatomical structure with variations that challenges the performance of individualized anterior clinoidectomy in treating lesions with different extents of invasion. In the present study, we established a 6-surface system for the ACP based on anatomical landmarks and analyzed its value in guiding ACP drilling and resection of paraclinoid meningiomas. Using the anatomical characteristics of 10 dry skull specimens, we set 9 anatomical landmarks to delineate the ACP into 6 surfaces. Guided by our 6-surface system and eggshell technique, 5 colored silicone-injected anatomical specimens were dissected via a frontotemporal craniotomy to perform anterior clinoidectomy. Next, 3 typical cases of paraclinoid meningioma were selected to determine the value of using our 6-surface system in tumor resection. Nine points (A-H and T) were proposed to delineate the ACP surface into frontal, temporal, optic nerve, internal carotid artery, cranial nerve III, and optic strut surfaces according to the adjacent tissues. Either intradurally or extradurally, the frontal and temporal surfaces could be identified and drilled into depth, followed by skeletonization of the optic nerve, cranial nerve III, internal carotid artery, and optic strut surfaces. After the residual bone was removed, the ACP was drilled off. In surgery of paraclinoid meningiomas, our 6-surface system provided great benefit in locating the dura, nerves, and vessels, thus, increasing the safety of opening the optic canal and relaxing the oculomotor or optic nerves and allowing for individualized ACP drilling for meningioma removal. Our 6-surface system adds much anatomical information to the classic Dolenc triangle and can help neurosurgeons, especially junior ones, to increase their understanding of the paraclinoid spatial structure and accomplish individualized surgical procedures with high safety and minimal invasiveness.

International Tuberculum Sellae Meningioma Study: Preoperative Grading Scale to Predict Outcomes and Propensity-Matched Outcomes by Endonasal Versus Transcranial Approach.

Tuberculum sellae meningiomas are resected via an expanded endonasal (EEA) or transcranial approach (TCA). Which approach provides superior outcomes is debated. The Magill-McDermott (M-M) grading scale evaluating tumor size, optic canal invasion, and arterial involvement remains to be validated for outcome prediction. The objective of this study was to validate the M-M scale for predicting visual outcome, extent of resection (EOR), and recurrence, and to use propensity matching by M-M scale to determine whether visual outcome, EOR, or recurrence differ between EEA and TCA. Forty-site retrospective study of 947 patients undergoing tuberculum sellae meningiomas resection. Standard statistical methods and propensity matching were used. The M-M scale predicted visual worsening (odds ratio [OR]/point: 1.22, 95% CI: 1.02-1.46, P = .0271) and gross total resection (GTR) (OR/point: 0.71, 95% CI: 0.62-0.81, P < .0001), but not recurrence ( P = .4695). The scale was simplified and validated in an independent cohort for predicting visual worsening (OR/point: 2.34, 95% CI: 1.33-4.14, P = .0032) and GTR (OR/point: 0.73, 95% CI: 0.57-0.93, P = .0127), but not recurrence ( P = .2572). In propensity-matched samples, there was no difference in visual worsening ( P = .8757) or recurrence ( P = .5678) between TCA and EEA, but GTR was more likely with TCA (OR: 1.49, 95% CI: 1.02-2.18, P = .0409). Matched patients with preoperative visual deficits who had an EEA were more likely to have visual improvement than those undergoing TCA (72.9% vs 58.4%, P = .0010) with equal rates of visual worsening (EEA 8.0% vs TCA 8.6%, P = .8018). The refined M-M scale predicts visual worsening and EOR preoperatively. Preoperative visual deficits are more likely to improve after EEA; however, individual tumor features must be considered during nuanced approach selection by experienced neurosurgeons.