The cranial nerves

There are 12 pairs of cranial nerves that are individually named and numbered using Roman numerals. Only some cranial nerves are mixed in function, i.e. they carry both sensory and motor fibres; others are purely sensory or motor and some may also carry pre- or post-ganglionic parasympathetic fibres. They pass through foramina in the base of the skull and are the olfactory (through cribriform plate to the nasal cavity), optic (through the optic foramen to the eye), oculomotor (through the cavernous sinus and superior orbital fissure to supply the eye), trochlear (as per oculomotor), trigeminal (three main branches that pass through the superior orbital fissure, foramen rotundum and foramen ovale, respectively), abducens (as per oculomotor), facial (through stylomastoid foramen to supply muscles of facial expression), vestibulocochlear (through the internal acoustic canal to control balance and hearing), glossopharyngeal, vagus, accessory (all pass through the jugular foramen) and hypoglossal (through the hypoglossal canal to control movements of the tongue) nerves.

Bilateral Orbital Apex Syndrome Related to Sphenoid Fungal Sinusitis

Orbital apex syndrome (OAS) is a rare condition that usually occurs due to damage to surrounding inner and surrounding bone tissue. Orbital apex syndrome may result from a variety of conditions that cause damage to the superior orbital fissure and to the optic canal leading to optic nerve (II) dysfunction. We recently experienced a rare case of sphenoidal Aspergillosis, which damaged the adjacent cavernous sinus structures and led to the definite symptom of bilateral OAS in a 77-year-old male. We present this rare case with a brief review of these disease’s entities.

Surgical treatment of tumors of the orbit and cranio-orbital region

Background. Surgical treatment of space-occupying orbital masses and cranio-orbital tumors is relevant due to the features of the diagnosis and surgical stage of treatment because of the dense arrangement of neurovascular and muscular structures in a small orbital space. The purpose was to determine the features of the surgical treatment of orbital and cranio-orbital tumors. Mate­rials and methods. A retrospective analysis of 102 patients (76 women, 26 men) with orbital and cranio-orbital tumors who were treated at the Department of Neurosurgery 2 at Kyiv City Clinical Emergency Hospital from 2000 to 2016 was carried out. Results. Eighty-six (84.3 %) patients had benign tumors, 16 (15.7 %) — malignant. Pterional craniotomy with orbitotomy was performed in 72 (70.6 %) cases, lateral orbital approach was used in 20 (19.6 %) patients, and anterior orbitotomy — in 10 (9.8 %). Total tumor resection was achieved in 71 (69.6 %) cases. After the removal of tumors located in the anterior 2/3 of the orbit and orbital apex, a satisfactory and good result was achieved in 93.9 and 92.4 %, respectively. The worst results were obtained after surgical treatment of tumors located in the posterior third of the orbit, which were intra- and extraconal, unsatisfactory results was observed in 37.5 % of cases in each group (II and III). In the early postoperative period, 18 (17.6 %) patients had complications, the most frequent were: visual impairment — 8.8 %, oculomotor di­sorders — 8.8 %, and ptosis — 5.9 %. However, in 6 patients they regressed by the time of discharge. The risk of complications was higher after the removal of intraconal tumors of the posterior third of the orbit (odds ratio 5.71 (95% confidence interval 1.28–25.55), p = 0.012), and did not depend on histological structure. Conclusions. The choice of a surgical approach for removing orbital and cranio-orbital tumors depends on the relation of the tumor to the plane of optic nerve, muscular cone, optic canal, superior orbital fissure. The results of the treatment for orbital and cranio-orbital tumors depended primarily on the location and spread of the process at the time of surgery. Worsening of symptoms after surgical treatment was found mainly in patients with tumors of the posterior third of the orbit.

Pretemporal Transcavernous Approach for Resection of an Orbito-Cavernous Oculomotor Schwannoma

The following operative video demonstrates surgical tenets and nuances of the pretemporal transcavernous approach in an unusual case of a 33-year-old patient suffering new onset diplopia and a third nerve palsy due to an orbito-cavernous oculomotor schwannoma. Near total resection was accomplished through an extended pterional craniotomy with pretemporal transcavernous exposure of her lesion, resulting in resolution of her preoperative oculomotor palsy and visual dysfunction. When combined with extended pterional and modified frontotemporal orbitozygomatic approaches, the pretemporal transcavernous approach provides excellent surgical access to the parasellar region including the superior orbital fissure and cavernous sinus. Meticulous dissection and early identification of tissue planes, including cranial nerve and vascular anatomy, allows for safe removal of tumors arising in this region.The link to the video can be found at: https://youtu.be/EuIRTP7wWBQ.

Orbital Extramedullary Plasmacytoma: Case report and literature review

Extramedullary plasmacytoma is a rare disease, characterized histopathologically by infiltration of plasma cells of different maturities and producing monoclonal immunoglobulin outside the bone marrow. J.R.G., 52 years old, male, sought medical assistance due to amaurosis and blocked eye movements. We performed Magnetic Nuclear Resonance of the skull that showed discrete intermediate signal tissue, next to the optic nerve canal and homolateral superior orbital fissure, with slight extension to the lower orbital fissure, associated with thickening of the corresponding meninges, involving the proximal portion of the optic nerve, measuring 1.3 x 1.1 x 2.5 cm. Non-specific aspect, but suggestive of lymphoproliferative lesion. Right and extraorbital tumor excision was performed, in which it was not possible to completely resect the tumor. The anatomopathological examination of the piece showed a neoplasm of plasma cells (plasmacytoma). The diagnosis is made from the exclusion of Multiple Myeloma. The treatments of choice are radiotherapy, due to the high radiosensitivity in 80–100% of cases, and surgery for localized lesions.

Cranio-Orbital Pretemporal Approach for Resection of Right Superior Orbital Fissure/Orbital Renal Cell Metastasis: 2-Dimensional Operative Video

Orbital metastatic lesions are rare entities1-3 best treated with radical surgical resection with preservation/improvement of neurological and visual function.1-9 Renal cell metastases, in particular, respond less favorably to radiation.9 To our knowledge, an operative video of microsurgical resection of a renal cell carcinoma metastasis to the superior orbital fissure and orbit has not been reported. A patient presented with worsening right eye vision as demonstrated on preoperative visual field testing and found to have a 3 × 1 × 1 cm lesion in the orbit and superior orbital fissure. The patient was placed supine and stealth neuronavigation was used to aid in tumor localization and extension. A cranio-orbital craniotomy and pretemporal exposure2,10,11 were performed to allow extradural dissection of the dura propria off the lateral wall of the cavernous sinus. Right-sided extradural cranial nerves II, III, IV, V1, and V2 were identified, and a high-speed diamond drill was used to perform extradural anterior clinoidectomy and optic nerve decompression. Microsurgical resection of the intraorbital tumor components was performed by the senior author (KIA) to delineate the plane between tumor and periorbita. An oval-shaped dural opening was made to resect the dura involved by tumor, confirmed on histological analysis, followed by closure via dural allograft. The patient's right-sided visual field improved markedly after surgery. Metastatic renal cell carcinoma of the orbit should be resected while preserving and improving preoperative neurological and visual function. The orbitocranial pretemporal approach offers wide visualization to achieve surgical resection. The patient provided written consent and permission to publish her image.

Sphenoidal artery: review of the literature and analysis of a dissected arterially injected fetal orbit

Purpose The sphenoidal artery is considered a component of the complex and dangerous arterial anastomoses of the human orbitocranial region, particularly with the advent of interventional neuroimaging. The objective of this publication was to analyze the various descriptions of the sphenoidal artery in the literature as related to relevant photographs of a dissected arterially injected fetal middle cranial fossa and orbit. Methods Publications dealing with middle meningeal-ophthalmic arterial anastomoses, focusing on the sphenoidal artery, were reviewed. A relevant dissection of a fetal specimen was analyzed. Results The literature dealing with the sphenoidal artery is at times not in agreement. The nomenclature and anatomy of its passage through the superior orbital fissure or Hyrtl canal have variable descriptions. Photographs of the skull base of a dissected arterially injected fetal specimen show bilateral prominent orbital branches of the middle meningeal arteries. These branches entered both orbits in a course similar to the diagrammatic representations of the sphenoidal artery, and give rise to several major intraorbital arteries. This study provides the only photographic image in the literature of this variation in a human fetal anatomic dissection. Conclusions Review of the literature dealing with the sphenoidal artery shows inconsistent nomenclature and conflicting descriptions of its anastomotic connections, and varying evolutionary and embryologic theories. Analysis of the dissected fetal skull base indicates that the sphenoidal artery is not a distinct artery but just a middle meningeal orbital arterial branch, an important component of the complex and dangerous arterial anastomoses of the human orbitocranial region.

Sternberg's Canal and Defect: Is the Lateral Craniopharyngeal Canal a Source of Spontaneous Cerebrospinal Fluid Leak? Anatomic and Radiological Analysis in Pediatric and Adult Populations

BACKGROUND The lateral craniopharyngeal or Sternberg's canal (SC) originates from superior orbital fissure (SOF) and traverses the sphenoid body into the nasopharynx. A remnant of the canal, Sternberg's defect (SD), has been debated as a source of cerebrospinal fluid (CSF) leak. The canal was described in 1888, and there is limited accurate visual illustration in the literature. OBJECTIVE To provide a detailed anatomic and radiological illustration of the canal in pediatric and adult population including the mechanism undermining the incidence of the canal, and the possibility of the canal as a source of CSF leak. METHODS A total of 195 high-resolution computed tomographies (CT) of patients (50 3-yr-old, 20 5-yr-old, and 125 adults) and 43 dry adult skulls (86 sides) were analyzed for a canal matching the description of the SC. RESULTS A SC was identified in 86% of the 3-yr-old and 40% of 5-yr–old patients. The diameter and length were 2.12 mm and 12 mm, respectively. The incidence of the canal decreased with age as sinus pneumatization extended into the sphenoid sinus. Only 0.8% of the adult skull on CT had the canal. The canal was not present on the dry adult skulls examination, but SD was found in 4.65%. CONCLUSION SC exists with high incidence in the pediatric group. Sinus pneumatization obliterates the canal in the adult population, leaving a defect in 4.65% of cases, which given the location and related anatomic structures, is unlikely to be a source of CSF leak.

Tolosa-Hunt syndrome relapse during pregnancy following chronic intake of combined oral contraceptives

Tolosa-Hunt syndrome (THS) is a rare syndrome of painful ophthalmoplegia secondary to an idiopathic granulomatous inflammation affecting the cavernous sinus, superior orbital fissure or orbit. Pregnancy and pregnancy-related hormones have been identified as potential triggers. A 39-year-old gravida-2 para-1 woman with prior chronic intake of combined oral contraceptives (COC) suffered two episodes of painful ophthalmoplegia—the first event with spontaneous remission and the relapse occurring during pregnancy and with complete resolution following steroid treatment. MRI revealed a postinflammatory mass at the junction of the left orbital apex and anterior cavernous sinus, supporting the diagnosis of THS. To our knowledge, this is the first report of a THS relapse occurring during pregnancy following a chronic history of COC intake. This case adds to the growing evidence supporting the relationship between immune and hormonal factors that may be present during pregnancy and the disease pathogenesis of THS.