Skull base surgery is an advanced surgical subspeciality. A wide range of pathologies can primarily or secondarily involve the skull base. Due to its complex anatomy, cross-sectional imaging is an important part in the multidisciplinary approach for skull base lesions.

To assess the outcomes of endonasal endoscopic repair of spontaneous cerebrospinal fluid (CSF) rhinorrhea and to analyze its possible etiological factors.

During the period between January 1999 and November 2011, 173 patients who presented with spontaneous CSF rhinorrhea underwent endonasal endoscopic surgery. Preoperative examination included CT scans, nasal endoscopy, measurement of glucose concentration in the nasal discharge and, in some cases, cisternographic evaluation via CT or MRI. CSF fistula closure was performed using endonasal endoscopic technique under general anesthesia. In all, 186 surgeries (173 primary attempts and 13 revisions) were carried out over the 12-year period. A combination of different plastic materials, i.e. nasal septum cartilage, facia lata, abdominal fat, rotating middle turbinate flaps, and fibrin glue was used for fistula repair.

At the time of the surgery, sites of the CSF fistula were determined as follows: Cribriform plate—70, fovea ethmoidalis—55, sphenoid sinus—45, frontal sinus—3. Extremely pneumatized lateral extension of the sphenoid sinus was found in 26 patients, and a meningo/encephalocele protruding through the bony defect was the source of the leak in 23 of them. In terms of up to 11 years, 165 patients were treated successfully after first attempt and five more recovered after revision endoscopic surgery. Success rate after the first surgery was 95.4%, overall success rate—97.7%. There were no postoperative complications.

Possible etiological factors of this disease include obesity, innate skull base malformations, overpneumatized sphenoid sinus, particularly presence of its lateral extensions and the empty sella syndrome. Endoscopic endonasal repair of spontaneous CSF rhinorrhea appears to be a safe and successful procedure. However, technique of endoscopic closure of CSF fistulas in the lateral part of the sphenoid sinus needs further perfection.

Management of anterior skull base tumors has progressed steadily since AS Ketcham popularized the craniofacial surgical technique in the seventies with good results. In the past two decades, endoscopic sinonasal tumor resection has been established as an additional treatment option. For tumors that cross the anterior skull base, a cranial access is vital to encompass the tumor all around. For a select group of these transcranial lesions, the sinonasal component is suitable for an endoscopic endonasal oncologically safe resection along with a traditional transcranial access to complete the resection. This article endeavors to describe the endoscopicassisted craniofacial combining the advantages of a transnasal minimal access to reduce facial morbidity and the transcranial access for superior control of tumors with adequate margins.

Idiopathic intracranial hypertension (IIH) is a disorder of raised ICP without any obvious underlying brain pathology. Early intervention remains the key to success. The patients with BIH and vision threatening papilloedema should be taken up for optic nerve fenestration and the results are favorable in terms of visual outcome. The procedure is safe with few intraoperative or postoperative complications.

The complex anatomical relationships of the sinonasal compartment with the surrounding vital structures make it vulnerable, yet simultaneously surgically accessible. Sinonasal tumors, especially those extending beyond, toward the anterior skull base and orbit have always posed a challenge, as far as their en bloc, and when applicable, oncologically safe removal is concerned. Traditionally, numerous external approaches have been employed for their successful removal. With advancements in endoscopic sinus surgical techniques and instrumentation, a majority of these tumors can be removed via purely transnasal endoscopic, and sometimes endoscopicassisted procedures.

A series of 61 sinonasal tumors have been managed by endoscopic or endoscopic-assisted procedures over the last 6 years. The principles of their management and the challenges posed have been highlighted. Methods to tackle the same, backed by evidence from numerous international studies have been applied to these, and the outcome discussed.

Endoscopic and endoscopic-assisted procedures are proving to be an effective alternative to the traditional external approaches for the management of sinonasal malignancies with comparable results. However, a long-term meta-analysis is imperative to corroborate these results.

Recent technological advances and growing cooperation between otorhinolaryngologists and neurosurgeons, coupled with an increasing knowledge of the anatomy of the ventral skull base, have led to the development of a series of surgical approaches to this region. Utilizing the nasal corridor, these expanded endonasal approaches (EEAs) benefit from the increased luminosity and definition provided by the endoscope to navigate through this corridor and reach a multitude o pathologies, both neoplastic and degenerative in nature. One of their common uses is to address tumors that arise from or invade the anterior cranial fossa; these lesions may include olfactory groove meningiomas, esthesioneuroblastomas and sinonasal malignancies. In order to safely resect these tumors through EEAs the surgical team must adhere to a series of steps, while planning the procedure as well as carrying it out. In this review article, the authors present these steps and describe the main patient selection criteria and complication avoidance strategies related to expanded endonasal approaches to the anterior skull base.

Although Maxmillan Sternberg described this anatomical entity (the lateral craniopharyngeal canal or the Sternberg's canal) as far back as in 1888, it has only recently stirred much controversy in world medical literature.

A review of contemporary world literature on this subject has been made and applied to the authors’ personal surgical experience of managing 21 spontaneous cerebrospinal fluid (CSF) leaks over a period of 6 years, with special focus on lateral sphenoid CSF leaks, in an attempt to understand their philosophy and clinical course.

Due to the rarity of such spontaneous CSF leaks (in all the published world series as well as the authors’ personal experience), it is difficult to comment on the exact site of congenital ‘weakness’, i.e. Sternberg's canal. Similar body profiles of all the patients in most series further complicates the scenario.

While one school of thought based on clinical and cadaveric studies hypothesizes, the Sternberg's canal to be present lateral to the foramen rotundum, the other based entirely on radiological analysis of 1000 CT scans of the paranasal sinuses proposes it to be medial to the foramen rotundum. Most patients with lateral sphenoid sinus CSF leaks (in world literature as well as the authors’ personal experience), are obese middle-aged women irrespective of whether the leak arises medial or lateral to the foramen rotundum. Thus, two strong and valid theories as regards the origin and existence (in adult life) of the Sternberg's canal are present and a multicentric, combined clinicoradiological, meta-analytical approach may probably serve as a solution to this controversy.

Traumatic optic nerve damage after craniofacial injury was first described by Hippocrates.1 Although the natural history of traumatic optic neuropathy is unknown, recent studies suggest that high dose steroids and, even surgical decompression of the optic canal or the nerve sheath (in cases of nerve sheath hematoma) may restore vision in selected patients.2-8 The commonest cause of optic nerve trauma is road-traffic accidents, when the patient has poly-trauma with head injury and the visual loss is noticed only after the general condition of the patient improves. Isolated trauma of the optic nerve is usually associated with blunt skull trauma involving fractures of both skull and optical canal, but may also occur from blunt ocular trauma.9 Iatrogenic trauma to the optic nerve is not unknown.

The part of the optic nerve most vulnerable to blunt trauma of the head is the intracanalicular segment, which by virtue of its bony course is vulnerable to the fractures and compressive-elastic forces of its surrounding bone, which also being unyielding, allows for no space for inflammatory expansion or hemorrhage.¹⁰ Optic neuropathy following accidental trauma usually results from two distinct mechanisms: A primary injury as a result of a direct contusive force on the optic canal and nerve, which if untreated results in a secondary ischemia with further damage to the nerve.

Clinical assessment should include testing of visual acuity, extraocular muscle motility and papillary reactivity, visual field assessment and direct/indirect ophthalmoscopy. Visual evoked potentials (VEPs) to flash stimulation and the electroretinogram (ERG) might be supportive in unresponsive patients in the immediate aftermath of the traumatic event.^11,12 The role of neuroimaging remains controversial, and practice varies between institutions. Recently, ultrasonography has been advocated to screen and detect abnormalities in optic nerve diameter.

Currently, there is no validated approach to the management of traumatic optic neuropathy. Thus, with numerous conflicting reports on the management of traumatic optic neuropathy, there is little world consensus on the optimal management of this condition. Keeping in mind the above, we have devised a management protocol for the same, simultaneously discussing the role of conservative/medical management as well as the surgical protocols followed by us.

In summary, optic nerve decompression alone or combined with decompression of the nerve sheath may be indicated in selected patients who fail to respond to high-dose intravenous steroids. The definitive role of surgery in the management of traumatic optic neuropathy remains unclear. There is a need for a large, prospective, randomized controlled trial to assess the different therapeutic approaches in traumatic optic neuropathy, but such a trial may be challenging given the low frequency of the condition and the difficulties inherent in randomizing patients.

Management of nose and paranasal sinus tumors involving the cribriform plate with or without invasion of anterior cranial fossa is complex due to the anatomic detail of the region and the variety of tumors that occur in this area. Anterior craniofacial resection is recognized as the best treatment for nose and paranasal sinus, tumors involving the cribriform plate with or without invasion of anterior cranial fossa. Craniofacial resection allows wide exposure of the complex anatomical structures at the base of skull permitting monobloc tumor resection.

Twenty-one patients underwent anterior craniofacial resection for nose and paranasal sinus tumors involving the cribriform plate with or without invasion of anterior cranial fossa at Himalayan Institute of Medical Sciences, Dehradun between 2000 and 2011 by a team of head-neck surgeons and neurosurgeons.

The series included 16 malignant tumors of the nose and paranasal sinuses and five extensive benign lesions. The mean age was 47.4 years (range, 12 to 68 years). There were 16 men and five women (M:F- 3.2:1.0). Four patients had a recurrence after previous treatments (surgery and/or radiotherapy). The histological subdivision was as follows: Seven cases of squamous cell carcinoma, four cases of adenocarcinoma, three cases of esthesioneuroblastoma, and two cases of undifferentiated tumors. All tumors were resected by a combined bifrontal craniotomy and rhinotomy. The skull base was closed with a pediculated pericranial flap and a split-thickness free skin graft underneath. There were no postoperative problems of CSF-leakage or meningitis, two patients had wound infection. Recurrent tumor growth or systemic metastasis occurred in three (18.75%) out of 16 patients with malignant tumors, 6 months to 2 years postoperatively. The mean follow-up was 16 months.

An anterior craniofacial resection should be performed in cases of nose and paranasal sinus tumors involving the cribriform plate with or without invasion of anterior cranial fossa.