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Background Surgical treatment of ventral and ventrolateral lesions of the craniocervical junction are among the most challenging neurosurgical pathologies to treat. Three surgical techniques, the far lateral approach (and its variations), the anterolateral approach, and the endoscopic far medial approach can be used to approach and resect lesions in this area. Objective The aim of the study is to examine the surgical anatomy of three skull base approaches to the craniocervical junction and review surgical cases to better understand the indications and possible complications for each of these approaches. Methods Cadaveric dissections with standard microsurgical and endoscopic instruments were performed for each of the three surgical approaches, and key steps and surgically relevant anatomy were documented. Six patients with appropriate pre-, post-, and intraoperative imaging and video documentation are presented and discussed accordingly. Results Based on our institutional experience, all three approaches can be utilized to safely and effectively approach a wide variety of neoplastic and vascular pathology. Unique anatomical characteristics, lesion morphology and size, and tumor biology should all be considered when determining the optimal approach. Conclusion Preoperative assessment of surgical corridors with 3D illustrations helps to define the best surgical corridor. 360 degree knowledge of the anatomy of craniovertebral junction allows safe surgical approach and treatment of ventral and ventrolateral located lesions using one of the three approaches. [ABSTRACT FROM AUTHOR]

Introduction Preserving cranial nerve (CN) function during tumor removal at the jugular foramen is challenging. No anatomical study has better defined the relevant dural septations on the inner surface of the jugular foramen. This study was undertaken to elucidate this anatomy. Methods Fourteen cadaveric heads (28 sides) were dissected, and relationships of the meningeal coverings of the jugular foramen and adjacent CNs documented. A classification scheme was created to better describe the dural septations of the inner surface of the jugular foramen. Results Four types of dural septations were noted. Type I: 10 sides (36%) where a dural septation was seen between CNs IX anteriorly and X and XI posteriorly. Of these, the septum was ossified in 20%. Type II (32%) was defined as a jugular foramen with no dural septation. Type III (7%) was defined as septation between CNs IX and X anteriorly and XI posteriorly. Type IV (7 sides, 25%) or the chaotic form was defined asmultiple septations within the jugular foramen that housed and divided CN rootlets. Conclusions The dural septations defined here can be used in future studies to help correlate operative strategy to meningeal morphology within the jugular foramen. [ABSTRACT FROM AUTHOR]

Objective The evolution of neurosurgical techniques during Harvey Cushing's practice was immense. The authors illustrate this evolution using archived historical records from Harvey Cushing. Setting Historical patient records retained by the Cushing Center at Yale University Department of Neurosurgery. Design The authors present the case of one of Cushing's patients with a cholesteatoma. Results Cushing's surgical treatment of a cholesteatoma extending into the skull base is an example of his meticulous documentation and accelerated surgical techniques. Conclusions This case demonstrates how neurosurgical techniques advanced in the management of complex skull base tumors via a staged approach through the middle and posterior fossae at a time long before the development of modern skull base surgery. [ABSTRACT FROM AUTHOR]

Introduction: We have previously argued that the clinical entity of dorsal third ventricular cyst in association with agenesis of the corpus callosum is a developmentally, radiologically, and clinically distinct and separate entity from the dorsal cyst of alobar holoprosencephaly. Patients and methods: Herein, we describe seven patients who underwent treatment of their dorsal third ventricular cyst with fluid diversion and shunting and report their long-term follow-up. The authors reviewed the literature and discrepancies identified in differentiating dorsal third ventricular cysts and holoprosencephaly. Results: Postoperative scans showed evidence of cyst decompression and stabilization of head circumference. Two patients required shunt revision surgery for delayed malfunction while the remainder has had no revision surgery since initial placement. Conclusions: Given the good clinical outcome in comparison to alobar holoprosencephaly patients, we recommend fluid diversion in this population of patients. [ABSTRACT FROM AUTHOR]

Background: Fluorescent technology has recently become a valuable tool in the surgical management of neoplastic and vascular lesions. The availability of microscope-integrated fluorescent modules has facilitated incorporation of this technology within the microsurgical workflow. The currently available microscope integrated modules use 5-aminolevulinic acid (5-ALA) and indocyanine green (ICG) as fluorophores. Methods: Fluorescein sodium is a fluorescent molecule that has been used specifically in ophthalmology for the treatment of retinal angiography. A new microscope-integrated fluorescent module has been recently developed for fluorescein. We employed this technology to maximize resection of tumors and perform intraoperative angiography to guide microsurgical management of aneurysms and arteriovenous malformations. Results: Fluorescein fluorescence allows the surgeon to appreciate fluorescent structures through the oculars while visualizing non-fluorescent tissues in near natural colors. Therefore, the operator can proceed with microsurgery under the fluorescent mode. We present three representative cases in which the use of fluorescein fluorescence was found useful in the surgeon's decision making during surgery. Conclusions: The applications of this new microscope-integrated fluorescent module are multiple, and include vascular and oncologic neurosurgery. Further clinical investigations with large patient cohorts are needed to fully establish the role of this new technology. [ABSTRACT FROM AUTHOR]

The definition of a pre and postfixed brachial plexus is varied in the literature, which results in inconsistent conclusions for various studies. As anatomical variation is important both during clinical evaluation and surgical procedures of the brachial plexus, a review of this literature was performed. Based on our review, variation in the contribution to the brachial plexus is more the rule than the exception. These variations may lead to deviation from the expected dermatome distribution as well as differences in the motor innervation of muscles of the upper limb. Such variations may predispose patients to certain pathology such as thoracic outlet syndrome and may alter surgical approaches to the brachial plexus. [ABSTRACT FROM AUTHOR]

: IntroductionTransient neuroimaging findings associated with seizure activity have received relatively little attention in the neurosurgical literature. These abnormalities may mimick neoplastic or ischemic changes on magnetic resonance imaging (MRI), possibly leading to additional studies and surgical treatment.: Case descriptionA 17-year-old right-handed male was transferred to emergency room in status epilepticus. A MRI obtained 5 months before admission was negative. On the day of admission, he had multiple intermittent upper-left extremity partial seizures and prolonged secondary generalized seizures. An electroencephalogram (EEG) showed frequent epileptiform discharges over the right hemisphere posteriorly. A MRI study performed 2 days after admission revealed non-hemorrhagic abnormalities involving the right occipital region that were hyperintense on fluid-attenuated inversion recovery (FLAIR) and T2 weighted sequences. The apparent diffusion coefficient map was unremarkable. Follow-up MRIs, 3 and 11 months after admission, showed complete resolution of these lesions.: ConclusionImaging findings after status epilepticus may raise suspicion of ischemic or neoplastic lesions. These findings may be reversible. Further follow-up imaging may prevent unnecessary intervention. [Copyright &y& Elsevier]

Frontal lobe epilepsy has been better understood during the past two decades with the advent of technologies with improved localizing capabilities. Major technological advances in the ability to delineate structural and functional brain regions have led to a resurgence of interest in epilepsy surgery. Neuroimaging modalities have broadened the scope of what are now considered surgically remediable syndromes. In the following article, we attempt to review the current concepts regarding diagnosis and surgical management of frontal lobe epilepsy. [ABSTRACT FROM AUTHOR]

Introduction. Medically recalcitrant spasmodic torticollis may necessitate surgical intervention. One procedure used for this pathologic entity is intradural rhizotomy. However, some patients are symptomatic, perhaps due to an overlooked or underappreciated nerve of McKenzie. The authors' goal was to further elucidate the anatomy of this nerve of the craniocervical junction. Materials and methods. Fifteen adult cadavers (30 sides) underwent microsurgical dissection and observations of the nerve of McKenzie. Morphometrics were performed and anatomic relationships were documented under surgical magnification. Results. The nerve of McKenzie was found on 70% of sides and was always a single branch. Average length was 5.2 mm for left sides and 6 mm for right sides. Average diameter was 0.9 mm (0.5-1.2 mm). In two specimens, the nerve was found bilaterally. It pierced the first denticulate ligament on 11 sides (52.4%) and travelled through its two prongs on three sides (14.3%) to connect to the anteriorly placed C1 ventral root. On five sides, it was in intimate contact with the adventitia of the vertebral artery. It was more common on right sides and in males, and this was statistically significant. Conclusions. The authors identified the nerve of McKenzie in most specimens. This nerve, if overlooked during surgical treatment of spasmodic torticollis, may result in continued symptoms. The nerve of McKenzie was often concealed within the denticulate ligament or adventitia of the vertebral artery. The authors hope the data presented here will aid neurosurgeons and decrease complications in patients who undergo neurotomy for spasmodic torticollis. [ABSTRACT FROM AUTHOR]

Preventing possible complications during brain aneurysm surgery is mandatory to ensure a better outcome for patients. Currently, it is possible to rely on some technologic innovations such as motor evoked potential, endoscope-assisted surgery, dye with indocyanine green, and video angiography capable of supporting the surgeon's work. The innovation process has mainly assisted the endovascular technique compared with surgery. The latter, apart from some new technical expedients, always requires anatomic knowledge and optimal technical preparation. A careful patient selection, adequate surgical exposure, use of microsurgical techniques in expert hands, and meticulous postoperative management represent the key to success for the surgical treatment of cerebral aneurysms. [ABSTRACT FROM AUTHOR]

Objective: “Open” transcortical and transcallosal approaches allow gross total colloid cyst resection but require a wider surgical corridor through normal brain tissue compared with endoscopic techniques. Although the use of tubular retractor systems has been previously reported, the minimum required diameter size for the retractor tube has been approximately 16 to 22 mm. Our objective was to explore the use of smaller retractor tubes for total resection of colloid cysts. Methods: A minitubular retractor with a 12-mm diameter was used to access and resect colloid cysts using microsurgical techniques while preserving stereoscopic vision as an alternative to open and endoscopic surgical routes. Results: This technique was adopted in five patients with larger than 10-mm colloid cysts to allow for gross total resection of the cysts in every case without any complication. Conclusions: Smaller retractor tubes may be used for resection of colloid cysts while minimizing brain retraction injury and potentially improving outcomes. [ABSTRACT FROM AUTHOR]

Background Minimally invasive accesses to the anterior skull base include the endoscopic endonasal approach (EEA) and the supraorbital eyebrow approach. These 2 are often seen as competing approaches, not alternative or combinatory approaches. In this study, we evaluated the anatomic limitations of each approach and the combined approach for accessing the anterior skull base. Methods Ten neurovascular injected cadaver heads were used for the study. The supraorbital approach to the anterior skull base was performed on 5 heads, and EEA was done on the other 5 heads. Then, the supraorbital approach was added to the 5 heads receiving EEA. Visualization and surgical limitations were recorded by the ability to perform resection of the crista galli, anterior clinoid, cribriform plate, and planum sellae. Results The maximal lateral extension of EEA for anterior skull base was the midorbit line anteriorly but narrowing down toward the orbital apex. The limitation of the supraorbital approach was found mostly medial and anterior. Drilling of anterior skull base was impossible medially between the sphenoethmoidal suture and the posterior aspect of the crista galli. The combined approach showed complementary areas of visualization and surgical maneuverability. Three clinical cases were presented to illustrate the indications for the stand-alone supraorbital approach, EEA, and combined approach. Conclusion The limitations of the EEA when dealing with lateral extension of anterior skull base meningiomas, and the limitations of the supraorbital eyebrow approach for medial skull base drilling and reconstruction, can be overcome by a judicious, anatomically based combination of both approaches. [ABSTRACT FROM AUTHOR]

Background Skull base surgery requires knowledge of the intracranial venous sinuses, which overall have been well studied. However, the intercavernous sinuses and their contribution to the so-called circular sinus have received scant attention. Methods Dissection was performed on 35 latex-injected cadaveric heads with attention to the morphology of the anterior and posterior intercavernous sinuses. A scale was created to describe the presence and morphology of the intercavernous sinuses, and morphometrics were performed. Results Both anterior and posterior intercavernous sinuses were identified in 28 specimens (80%; type I). Of the 80% with both sinuses, a circular connection between these was found in 25% (type II). Only the anterior intercavernous sinus was observed in six specimens (17%; type III), and only the posterior sinus was seen in one specimen (2.9%; type IV). No specimen lacked both the anterior and the posterior intercavernous sinuses. The anterior intercavernous sinus was larger than the posterior intercavernous sinus in most specimens (n = 28). The anterior intercavernous sinus occupied the entire anterior wall of the sella turcica in five specimens. An inferior intercavernous sinus was present in only six specimens (17%) and was usually smaller than the anterior or posterior intercavernous sinuses. Conclusions A true “circular sinus” (type II) is present in only a few cases; both intercavernous sinuses disconnected are found in most specimens. No intercavernous sinus was found within the free edge of the diaphragma sella, which is typically depicted. These data are useful for invasive and minimally invasive procedures of the parasellar region. [ABSTRACT FROM AUTHOR]