Clear cell meningiomas are defined by a highly distinct DNA methylation profile and mutations in SMARCE1.

Clear cell meningioma represents an uncommon variant of meningioma that typically affects children and young adults. Although an enrichment of loss-of-function mutations in the SMARCE1 gene has been reported for this subtype, comprehensive molecular investigations are lacking. Here we describe a molecularly distinct subset of tumors (n = 31), initially identified through genome-wide DNA methylation screening among a cohort of 3093 meningiomas, of which most were diagnosed histologically as clear cell meningioma.

Brain invasion in meningiomas: does surgical sampling impact specimen characteristics and histology?

Brain invasion (BI) is a new criterion for atypia in meningiomas and therefore potentially impacts adjuvant treatment. However, it remains unclear whether surgical practice and specimen characteristics influence histopathological analyses and the accuracy of detecting BI. Tumor location, specimen characteristics, and rates of BI were compared in meningioma samples obtained from 2938 surgeries in different neurosurgical departments but diagnosed in a single neuropathological institute.

FGFR1:TACC1 fusion is a frequent event in molecularly defined extraventricular neurocytoma.

Extraventricular neurocytoma (EVN) is a rare primary brain tumor occurring in brain parenchyma outside the ventricular system. Histopathological characteristics resemble those of central neurocytoma but exhibit a wider morphologic spectrum. Accurate diagnosis of these histologically heterogeneous tumors is often challenging because of the overlapping morphological features and the lack of defining molecular markers.

Diffuse Astrocytoma, IDH-Wildtype: A Dissolving Diagnosis.

The histological and molecular features and even the mere existence of diffuse astrocytoma, IDH-wildtype, remain unclear. We therefore examined 212 diffuse astrocytomas (grade II WHO) in adults using IDH1(R132H) immunohistochemistry followed by IDH1/IDH2 sequencing and neuroimaging review. DNA methylation status and copy number profiles were assessed by Infinium HumanMethylation450k BeadChip.

Prospective analysis of neuropsychological deficits following resection of benign skull base meningiomas.

OBJECTIVE Resection of skull base tumors is challenging. The introduction of alternative treatment options, such as radiotherapy, has sparked discussion regarding outcome in terms of quality of life and neuropsychological deficits. So far, however, no prospective data are available on this topic.

Cerebral amyloidoma is characterized by B-cell clonality and a stable clinical course.

Amyloidomas are rare amyloid-containing lesions, which may also occur in the central nervous system. Etiology, pathogenesis and clinical course are poorly understood. To gain more insight into the biology of cerebral amyloidoma, they aimed to characterize its histopathological, molecular and clinical features in a retrospective series of seven patients.

Pathological Location of Cranial Nerves in Petroclival Lesions: How to Avoid Their Injury during Anterior Petrosal Approach.

 Numerous surgical approaches have been developed to access the petroclival region. The Kawase approach, through the middle fossa, is a well-described option for addressing cranial base lesions of the petroclival region. Our aim was to gather data about the variation of cranial nerve locations in diverse petroclival pathologies and clarify the most common pathologic variations confirmed during the anterior petrosal approach.

Prechiasmatic transection of the optic nerve in optic nerve glioma: technical description and surgical outcome.

Optic pathway glioma (OPG) encompasses a spectrum of findings ranging from lesions confined to the optic nerve only, lesions affecting the optic chiasm and hypothalamus, and lesions with diffuse involvement of a large part of the optic pathway and neighboring structures. The majority of pediatric low-grade astrocytomas in the optic/chiasmatic region are typical pilocytic astrocytoma. The rest of them (10 %) may be other gliomas such as fibrillary pilomyxoid astrocytoma (grade 2 WHO).

Anterior petrosal approach: The safety of Kawase triangle as an anatomical landmark for anterior petrosectomy in petroclival meningiomas.

Object: Anterior petrosectomy through the middle fossa is a well-described option for addressing cranial base lesions of the petroclival region. To access posterior fossa through middle fossa, we quantitatively evaluate the safety of Kawase triangle as an anatomical landmark.

Method: We reviewed pre- and postoperative Multi-Slice CT scan (1mm thickness) of patients with petroclival meningioma between Jan 2009 and Sep 2013 in which anterior petrosectomy was performed to access the posterior fossa part of the tumor.

Multi-size, Multi-angle Microbipolar Forceps for Skull Base Surgery: Technical Note.

Objective Hemorrhage control in skull base surgery is critical but hindered by the lack of instruments suitable for coagulating structural curves and corners. The main impediment is that most of the instruments currently used are right-angled and unsuitable because anatomical and pathologic structures are three-dimensional objects having complex curves and corners. In this article, we present a solution: the use of angled bipolar microforceps having a range of small diameters and angles for dissection and coagulation.

Disabling vertigo and tinnitus caused by intrameatal compression of the anterior inferior cerebellar artery on the vestibulocochlear nerve: a case report, surgical considerations, and review of the literature.

Microvascular compression of the vestibulocochlear nerve is known as a cause of tinnitus and vertigo in the literature, but our review of the literature shows that the compression is usually located in the cerebellopontine angle and not intrameatal. We present a case of intrameatal compression of the anterior inferior cerebellar artery (AICA) on the vestibulocochlear nerve of a 40-year-old woman with symptoms of disabling vertigo and intermittent high-frequency tinnitus on the left side without any hearing loss for ∼ 4 years. Magnetic resonance imaging of the brain did not show any abnormality, but magnetic resonance angiography showed a left intrameatal AICA loop as a possible cause of the disabling symptoms.

Sacral dural arteriovenous fistula presented as an acute isolated thoracic myelopathy: clinical and surgical importance.

Unlabelled: We report a case of dural Arteriovenous Fistula (AVF) supplied by the lateral sacral artery that is located in the sacral region and presented as isolated thoracic myelopathy.

Method And Results: After S3 hemilaminectomy and opening the dura, the engorged arterialized vein has been interrupted. Postoperatively, the patient's symptoms and myelopathy gradually resolved.

Pre-chiasmatic transection of the optic nerve can save contralateral vision in patients with optic nerve sheath meningioms.

Objectives: With respect to its characteristic pattern of growth from the orbit into the intracranial space toward the chiasm, patients with optic nerve sheath meningiomas (ONSM) are threatened to loose function of both optic nerves. Fortunately, in less than 5% both optic nerves are involved initially. Hence, prevention of vision of the contralateral eye is the foremost aim of any therapy.

"Münster correlation" in temporal bone: surgical relevance of an anatomical study.

Resection of the temporal bone to various degrees provides different levels of access to lesions of the posterior fossa. However, precise distances to the petrosal bone are still not clearly described. We evaluated the different distances of temporal bone landmarks in order to assess their variations and the possible correlations between them.

Isolated primary craniopharyngioma in the cerebellopontine angle.

Between January 2000 and January 2011, we diagnosed three patients with isolated craniopharyngioma in the cerebellopontine angle (CPA). Brain MRI revealed cystic lesions with various imaging characteristics, including hypointensity on T1-weighted (T1W) images and hyperintensity on T2-weighted (T2W) images. The first patient's lesion showed rim enhancement after gadolinium administration.

Helmet use in winter sport activities--attitude and opinion of neurosurgeons and non-traumatic-brain-injury-educated persons.

Purpose: During the last winter season, some fatal sport injuries with severe traumatic brain injury (TBI) prompted major discussions about protective helmet use. Although ski helmets reportedly lead to a 60% decrease of risk to incur TBI, little is known about the distribution of helmet users and which factors are crucial for the decision to wear a helmet. Especially, it is unknown whether knowledge or experience concerning TBI in winter sports influences the use of helmets, as well as the attitude and opinion of people.

Tentorial meningiomas with special aspect to the tentorial fold: management, surgical technique, and outcome.

Background: From a surgical perspective, tentorial fold (TF) meningiomas (TFM) are a unique entity of tumors. They involve the supra- and infratentorial space and often are in close contact to the cavernous sinus, cranial nerves, and the mesencephalon. Complete resection is challenging and can be hazardous.

Attitude and opinion of neurosurgeons concerning protective bicycle-helmet use.

Wearing protective helmets decreases the risk of incurring traumatic brain injury (TBI) in bicycle accidents. In 2007, the German Neurosurgical Society advocated compulsory use of bicycle helmets. Although neurosurgeons are the specialists who primarily treat patients with TBI in Europe, the distribution of helmet users among neurosurgeons (NS), as well as factors that influence the decision to wear helmets and whether professional knowledge or experience in TBI influences the use or attitude concerning bicycle helmets, remains unclear.

Treatment of deep vascular orbital malformations.

Objective: In this article, we discuss the clinical features and endovascular and/or surgical treatment of deep vascular orbital malformations.

Methods: We report on our treatment of 58 cases of vascular malformations of the orbit between 1991 and 2008.

Results: Arterial low flow lesions, such as cavernomas (n=44) were the most common finding.

The supraorbital approach--a minimally invasive approach to the superior orbit.

Background: We present a minimally invasive approach to the superior orbit via an eyebrow incision with a small osteotomy, minimal orbital rim resection and small frontal craniotomy.

Methods: This approach was used in 20 patients with a well-defined intra-and extraconal lesion superior to the optic nerve, who underwent surgery between 2000 and 2007.

Results: This approach is purely extradural with minimal brain and orbital retraction.

Spontaneous herniation of the spinal cord: operative technique and follow-up in 10 cases.

Object: The authors report on a series of 10 patients with spontaneous thoracic cord herniation, provide the longterm follow-up, and propose a surgical strategy.

Methods: All 10 patients had a defect in the ventral dura mater. They were all treated surgically with wide excision of the dura around the defect, repositioning of the cord, and reconstruction with a ventral patch.