The extradural neural axis compartment (EDNAC) is an adipovenous zone located between the meningeal and endosteal layers of the dura and has been minimally investigated. It runs along the neuraxis from the orbits down to the coccyx and contains fat, valveless veins, arteries, and nerves. In the present review, we have outlined the current knowledge regarding the structural and functional significance of the EDNAC. We performed a narrative review of the reported EDNAC data. The EDNAC can be organized into 4 regional enlargements along its length the orbital, lateral sellar, clival, and spinal segments, with a lateral sellar orbital junction linking the orbital and lateral sellar segments. The orbital EDNAC facilitates the movement of the eyeball and elsewhere allows limited motility for the meningeal dura. The major nerves and vessels are cushioned and supported by the EDNAC. Increased intra-abdominal pressure will also be conveyed along the spinal EDNAC, causing increased venous pressure in the spine and cranium. From a pathological perspective, the EDNAC functions as a low-resistance, extradural passageway that might facilitate tumor encroachment and expansion. Clinicians should be aware of the extent and significance of the EDNAC, which could affect skull base and spine surgery, and have an understanding of the tumor spread pathways and growth patterns. Comparatively little research has focused on the EDNAC since its initial description. Therefore, future investigations are required to provide more information on this underappreciated component of neuraxial anatomy. Clinicians should be aware of the extent and significance of the EDNAC, which could affect skull base and spine surgery, and have an understanding of the tumor spread pathways and growth patterns. Comparatively little research has focused on the EDNAC since its initial description. Therefore, future investigations are required to provide more information on this underappreciated component of neuraxial anatomy. Several bone grafting techniques for posterior atlantoaxial arthrodesis have been reported. The techniques of placing a cancellous morselized bone graft (MBG) on decorticated surfaces of the atlantoaxial complex and securing a structural iliac bone graft (SBG) between C1 and C2 have been used widely. The aim of the present study was to compare the outcomes of these 2 bone grafting techniques for atlantoaxial arthrodesis. The data from 64 patients with reducible atlantoaxial dislocation treated using posterior C1-C2 screw-rod fixation and fusion were retrospectively reviewed. The MBG technique had been used in 32 patients and the SBG technique in 32 patients. The time required for bone fusion was recorded. The outcomes were evaluated using the Japanese Orthopaedic Association scale score, Neck Disability Index, visual analog scale (VAS) score for neck pain, patient satisfaction, and neck stiffness and compared between the 2 groups. The donor site complications were also compared, and donor site pain was as. We describe the dural relationships and its surgical implications for large lower cranial nerve (CN) neurinomas. The study is based on surgical experience with 14 cases. During the period January 2014 to December 2019, 14 consecutive cases with large lower CN neurinomas were surgically treated with the aim of radical tumor resection. There were 9 males and 5 females, ranging in age from 17 to 65 years. All patients were operated in a single stage. The principal surgical observation was that the entire extent of tumor, which included intracranial, jugular fossa, and extracranial components, was within the "dural" confines and the tumor adjoining critical neural and vascular structures was displaced around the dome of the tumor. https://www.selleckchem.com/Androgen-Receptor.html Radical surgical resection was achieved in all cases. During the follow-up period that ranged from 3 to 71 months (average 32 months), no symptomatic recurrence was observed and no patient needed reoperation. At the time of last clinical follow-up, the lower CN function in all patients was better than at the time of presentation. The "dural" cover of the lower CN neurinomas forms a strong and reliable plane of compartmentalization and allows safe tumor resection. The "dural" cover of the lower CN neurinomas forms a strong and reliable plane of compartmentalization and allows safe tumor resection. We investigated the added value of combining information from direction-encoded color (DEC) maps with high-resolution structural magnetic resonance imaging scans (T1-weighted images [T1WIs]) to improve the identification of regions of interest (ROIs) for fiber tracking during preoperative planning for patients with brain tumors. The dataset included 42 patients with gliomas and 10 healthy subjects from the Human Connectome Project. For identification of the ROIs, we combined the structural information from high-resolution T1WIs and the directional information from DEC maps. To test our hypothesis, we examined the interrater and intrarater agreement. We identified specific ROIs to extract the main white matter bundles. The directional information from the DEC maps combined with the T1WIs (T1WI-DEC maps) had significantly facilitated ROI identification in patients with brain tumors, especially patients in whom the tracts had been displaced by the mass effect of the tumor. Fiber tracking using the combined T1WI-DEC maps showed significantly greater inter- and intrarater agreement compared with using either T1WI or DEC maps alone. Combining the information from diffusion-derived color-encoded maps with high-resolution anatomical details from structural imaging (T1WI-DEC map), especially in patients with brain tumors, could be useful for accurate identification of the ROIs. Combining the information from diffusion-derived color-encoded maps with high-resolution anatomical details from structural imaging (T1WI-DEC map), especially in patients with brain tumors, could be useful for accurate identification of the ROIs. Syrinx development in patients with spontaneous intracranial hypotension (SIH) has rarely been described. To better understand this entity, we compared the clinical and radiographic findings in a series of patients with SIH and acquired Chiari-like tonsillar herniation with and without syrinx formation. Six patients with syrinx in the setting of SIH and Chiari-like tonsillar herniation were retrospectively identified. The clinical and radiographic findings and outcomes were compared with those from a control group of patients with SIH and Chiari-like tonsillar herniation without syrinx. The patients with SIH and syrinx had had a higher opening pressure than had the control group (mean, 14.0 cm H O vs. 7.4 cm H O; P= 0.02) and a higher body mass index (mean, 33 kg/m vs. 26 kg/m ; P= 0.01). The patients with syrinx had had an average obex displacement of 3.7 ± 2.2 mm below the plane of the foramen magnum compared with a position of 1.9 ± 3.1 mm above the plane of the foramen magnum in the control group (P= 0.