Significant tumor compression of the middle cerebellar peduncle is associated with worse facial nerve outcomes and lower extent of resection in surgery for medium-sized vestibular schwannomas - A radiographic analysis of a case series.

Background And Objective: Optimizing the extent of resection (EOR) and facial nerve outcomes (FNO) remain a challenge in medium to large vestibular schwannomas (VS). Currently, tumor size has been the only consistently reported factor predicting FNO and EOR. Here, we sought to evaluate whether the degree of the tumor's compression on the middle cerebellar peduncle (PC) influences FNO and EOR in medium to large VS.

Lateral versus prone robot-assisted percutaneous pedicle screw placement: a CT-based comparative assessment of accuracy.

Objective: Single-position lateral lumbar interbody fusion (SP-LLIF) has recently gained significant popularity due to increased operative efficiency, but it remains technically challenging. Robot-assisted percutaneous pedicle screw (RA-PPS) placement can facilitate screw placement in the lateral position. The authors have reported their initial experience with SP-LLIF with RA-PPS placement in the lateral position, and they have compared this accuracy with that of RA-PPS placement in the prone position.

Study of comparative surgical exposure to the petroclival region using patient-specific, petroclival meningioma virtual reality models.

Objective: Despite advancement of surgical techniques, the attachments of petroclival meningiomas near the central clival depression (CCD) remain difficult to visualize. With existing methods, the amount of tumor near the CCD that is inaccessible through various approaches cannot be compared. Tumors distort the brainstem, changing the size of the operative corridor for some but not all approaches; therefore, using cadavers with normal posterior fossae makes it impossible to compare different approaches to the tumor.

Progressive Orbitotomy and Graduated Expansion of the Supraorbital Keyhole: A Comparison with Alternative Minimally Invasive Approaches to the Paraclinoid Region.

Background: Various minimally invasive approaches, such as supraorbital (SO), minipterional (MPT), and translateral orbital (TLO), can access the paraclinoid region. Studies have described these approaches individually but have not directly compared all of them in the same anatomic specimen.

Methods: Using virtual reality models generated from computed tomography studies of living subjects, we simulated TLO, MPT, and variations of SO approaches, without and with removal of the orbital rim and sphenoid wing.

Robot-Assisted Percutaneous Pedicle Screw Placement: Evaluation of Accuracy of the First 100 Screws and Comparison with Cohort of Fluoroscopy-guided Screws.

Objective: Percutaneous pedicle screws (PPS) are used to stabilize the spine after interbody fusion in minimally invasive approaches. Recently, robotic assistance has been developed to improve the accuracy of PPS. We report our initial experience with ExcelsiusGPS and compare its accuracy with our historical cohort of fluoroscopy-guided PPS.

Retrocondylar Far-Lateral Approach for Resection of a Craniocervical Junction Hemangioblastoma.

We present a case in which a retrocondylar far-lateral approach was utilized to resect a hemangioblastoma at the craniocervical junction. The patient was a 33-year-old man presenting with 2 months of symptoms referable to compression at the craniocervical junction (i.e.

The Benefits of Progressive Occipital Condylectomy in Enhancing the Far Lateral Approach to the Foramen Magnum.

Background: The portion of the occipital condyle that is safe to remove remains controversial in the transcondylar approach. We aimed to correlate the gain in exposure with incremental removal of the occipital condyle to determine if there is a point where further drilling yields diminishing gains.

Methods: Virtual reality rendering of the skull was generated from 25 subjects with no posterior fossa pathology.

Outcome of Microsurgery for Arteriovenous Malformations in a Resource-Restricted Environment: Single-Surgeon Series from Vietnam.

Background: The health care expenditure in Vietnam is equivalent to 1% of that in the United States. For most patients with brain arteriovenous malformations (AVM), surgery is the only available treatment modality. This study reports on the outcomes on AVM microsurgery in this resource-restricted environment.

Update on Trigeminal Neuralgia.

Purpose Of Review: To review current treatments for trigeminal neuralgia, with an emphasis on determining which patients may benefit from neurosurgical procedures.

Recent Findings: A detailed history is the most helpful tool for diagnosing trigeminal neuralgia (TN) and predicting response to neurosurgical treatments. Patients with classic trigeminal neuralgia will describe severe, unilateral, intermittent facial pain that is triggered by innocuous sensory stimuli.

The Benefits of Limited Orbitotomy on the Supraorbital Approach: An Anatomic and Morphometric Study in Virtual Reality.

Background: Cadaveric studies on surgical anatomy and approaches are hampered by the limited number of specimens. Virtual reality (VR) technology can overcome this limitation, allowing for more in-depth statistical analysis of the data.

Objective: To determine the benefit of a supraorbital ridge osteotomy in a supraorbital craniotomy targeting (1) the anterior communicating artery complex (ACOM), and (2) a lesion 25 mm above tuberculum sellae, using a large dataset generated by VR.

An anatomical study of the foramen of Monro: implications in management of pineal tumors presenting with hydrocephalus.

Background: For pineal tumors presenting with hydrocephalus, simultaneous endoscopic third ventriculostomy (ETV) and tumor biopsy is commonly used as the initial step in management. To analyze the restriction which the foramen of Monro poses to this procedure, one must start with a detailed description of the microsurgical anatomy of the foramen in living subjects. However, the orientation and shape of the foramen of Monro make this description difficult with conventional imaging techniques.

Refractory trigeminal neuralgia treatment outcomes following CyberKnife radiosurgery.

Introduction: A handful of studies have reported outcomes with CyberKnife radiosurgery (CKRS) for the treatment of trigeminal neuralgia. However, the follow-up has been short with no minimum follow-up required and have included patients with short duration of symptoms. Here we report our institutional experience on patients with a minimum follow-up of 1 year and a median follow-up of 28 months (mean 38.

Trigeminal neuralgia treatment outcomes following Gamma Knife radiosurgery with a minimum 3-year follow-up.

Objective: Effective short-term outcomes have been well documented for trigeminal neuralgia (TN) patients treated with Gamma Knife radiosurgery (GKRS) with reported success rates of 70-90 % with median follow-up intervals of 19-75 months. Fewer series, however, have described uniform long-term follow-up data. In this study, we report our long-term institutional outcomes in patients treated with GKRS after a minimum follow-up of 36 months.

Frameless fractionated stereotactic radiosurgery for vestibular schwannomas: a single-institution experience.

Objective: To examine tumor control, hearing preservation, and complication rates after frameless fractionated stereotactic radiosurgery (SRS) in patients with vestibular schwannomas (VS).

Methods: Thirty-seven patients treated with fractionated SRS from 2002 to 2011 were retrospectively analyzed. Ninety-five percent were treated with 25 Gy in five fractions, targeting a median tumor volume of 1.

EphA7 expression identifies a unique neuronal compartment in the rat striatum.

Prior studies have identified two anatomically and neurochemically distinct cellular compartments within the mammalian striatum, termed striosomes and matrix, which express μ-opioid receptors (μOR) and EphA4, respectively. Here we identify and characterize an additional compartment in the rat striatum composed of neurons that express EphA7. In situ hybridization and immunohistochemical data indicate that neurons expressing EphA7 mRNA and protein are arranged in a banded "matrisome-like" pattern confined to the matrix in the dorsal striatum.