Cystic Chordoma of the Cavernous Sinus.

Chordomas are the tumors commonly involving base of skull which are predominantly solid in consistency. A cystic chordoma of the cavernous sinus is an extremely rare entity and has never been reported. We report a 26-year-old male presenting with gradually progressive right-sided sixth nerve palsy and headache.

Treatment of "idiopathic" syrinx by atlantoaxial fixation: Report of an experience with nine cases.

Objective: The authors evaluate the significance of atlantoaxial instability in the management of idiopathic syringomyelia.

Background: We recently observed that atlantoaxial dislocation can be present even when the atlantodental interval was within normal range. Atlantoaxial instability can be identified on the basis of facetal mal-alignment or even by direct observation of status of joint during surgery.

Atlantoaxial Fixation for Basilar Invagination without Obvious Atlantoaxial Instability (Group B Basilar Invagination): Outcome Analysis of 63 Surgically Treated Cases.

Background: We discuss the rationale of surgical treatment of group B basilar invagination by atlantoaxial facet joint stabilization and segmental arthrodesis.

Methods: From January 2010 to April 2016, 63 patients with group B basilar invagination were surgically treated. All patients had varying degree of myelopathy-related functional disability.

Radiologic Evaluation of Basilar Invagination Without Obvious Atlantoaxial Instability (Group B Basilar Invagination): Analysis Based on a Study of 75 Patients.

Background: We evaluated the radiologic features of 75 patients with group B basilar invagination who exhibited no evidence of atlantoaxial instability based on the conventional parameter of an abnormal increase in the atlantodental interval. We specifically studied the variability and possible significance of the presence of cerebrospinal fluid (CSF) within and outside the confines of neural tissues.

Materials And Methods: During the period January 2008-May 2015, we encountered 75 cases with group B basilar invagination.

Three-dimensional models: an emerging investigational revolution for craniovertebral junction surgery.

Complex craniovertebral junctional anomalies can be daunting to treat surgically, and preoperative information regarding the osseous abnormalities, course of the vertebral arteries, size of the pedicles, and location of the transverse foramina is invaluable to surgeons operating on these challenging cases. The authors present their experience with the emerging technology of 3D model acquisition for surgery in 11 cases of complex craniovertebral junction region anomalies. For each case, a 3D printed model was made from thin CT scans using a 64-slice CT scanner.

Brain Herniation in Neurofibromatosis with Dysplasia of Occipital Bone and Posterior Skull Base.

A 22-year-old female, a known case of neurofibromatosis 1 (NF1), presented with a congenital swelling in the left occipital region. She had developed recent onset dysphagia and localized occipital headache. Neuroradiology revealed a left occipital meningoencephalocele and a left parapharyngeal meningocele.

Meningioma of foramen magnum causing drop attacks.

A 52-year-old female presented with frequent episodes of falls without loss of consciousness. These episodes lasted for brief period followed by full neurological recovery. Magnetic resonance imaging (MRI) of the brain showed foramen magnum meningioma encasing left vertebral artery.