Basilar Artery Herniation into the Sphenoid Sinus Secondary to Traumatic Skull Base Fractures: Case Report and Review of the Literature.

BACKGROUND: Traumatic clival fractures occur with less than 0.6% frequency and can be associated with significant neurovascular injuries. The most serious of these injuries is to the basilar artery in which the artery is dissected or is fully occluded, resulting in infarction of the brainstem and cerebellum. Among early reports of these injuries, postmortem autopsy showed entrapment, or incarceration, of the basilar artery at the clival fracture site. A literature search revealed 11 cases of entrapment of the basilar artery within a clival fracture. CASE DESCRIPTION: This report describes a 59-year-old man after a motor vehicle crash with computed tomography showing a basilar artery herniation through a sphenoid sinus fracture. The patient subsequently developed brainstem and cerebellar infarcts. CONCLUSIONS: Basilar artery incarceration and herniation through the sphenoid sinus is rare. Such an injury portends a poor prognosis. We discuss the relevant clinical imaging and review the literature.

A Novel Approach Using Electromagnetic Neuronavigation and a Flexible Neuroendoscope for Placement of Ommaya Reservoirs.

OBJECTIVE: Placement of intraventricular catheters in oncology patients can be associated with morbidity given their small to slit-like ventricles and underlying hematologic disorders. We studied the accuracy of placing Ommaya reservoirs using neuronavigation and a flexible neuroendoscope to verify catheter positioning. METHODS: Ommaya reservoirs placed in 25 oncology patients between 2013 and 2015 were retrospectively reviewed. Twenty-five ventricular catheters were placed using the AxiEM stealth frameless neuronavigation system and a flexible neuroendoscope. Postoperative catheter accuracy, operative complications, and postoperative complications were assessed. We discuss surgical protocol and technical nuances. RESULTS: All ventricular catheters were successfully placed into the ipsilateral (84%) or contralateral (16%) foramen of Monro. A single ventricular catheter pass was needed to cannulate the ventricle in 96% of patients. The mean accuracy was 4.09 ± 3.47 mm from the target, the ipsilateral foramen of Monro. One patient had a catheter tract hemorrhage seen on postoperative imaging related to thrombocytopenia. No postoperative neurologic deficits were seen. CONCLUSIONS: A combined neuronavigation and neuroendoscopic approach improved catheter tip accuracy compared with accuracy rates described in the literature using other techniques. This approach can be adapted toward routine clinical practice of placing ventricular shunt catheters and Ommaya reservoirs.

Metastatic Mantle Cell Lymphoma to the Pituitary Gland: Case Report and Literature Review.

We present an unusual case of a metastatic mantle cell lymphoma (MCL) to the pituitary gland. The patient had a known history of MCL for which she previously received chemotherapy. She presented with new-onset diplopia and confusion, and reported a history of progressive vision blurriness associated with headache, nausea, and vomiting. MRI of the brain showed an enhancing lesion within the sella turcica involving the cavernous sinuses bilaterally, extending into Meckel's cave on the left, and abutting the optic nerves bilaterally. Following surgical excision, histopathology revealed the tumor to be a MCL. Metastatic pituitary tumors are rare and have been estimated to make up 1% of tumors discovered in the sellar region. The two most common secondary metastatic lesions to the sella are breast and lung carcinoma followed by prostate, renal cell, and gastrointestinal carcinoma. Metastatic lymphoma to the pituitary gland is especially rare and is estimated to constitute 0.5% of all metastatic tumors to the sella turcica. To our knowledge, this is the first reported case of MCL metastasizing to the pituitary gland.

Delayed Tension Pneumocephalus following Gunshot Wound to the Head: A Case Report and Review of the Literature.

Tension pneumocephalus is a rare complication of head trauma and neurosurgical procedures, amongst other causes. It is defined by the combination of intracranial air, increased intracranial pressure, and mass effect. Although it often presents soon after surgery, it can also rarely present in a delayed fashion. We present a case of delayed tension pneumocephalus, occurring approximately 16 weeks after bifrontal craniectomy for a self-inflicted gunshot wound. Following a month of rhinorrhea, postnasal drip, and cough, the patient presented with a sensation of expansion in the area of the right forehead. As tension pneumocephalus is an emergency that can be fatal, this patient was treated expediently and avoided severe neurological deficits. The case recounted here is important as a demonstrative example that tension pneumocephalus does not always follow a defined course immediately after trauma or neurosurgery but rather can develop insidiously without obvious signs.

Metastatic Renal Cell Carcinoma Mimicking Trigeminal Schwannoma in a Patient Presenting with Trigeminal Neuralgia.

We present an unusual case of a metastatic renal cell carcinoma (RCC) mimicking trigeminal schwannoma. The patient, with no prior history of RCC, presented with clinical symptoms and imaging consistent with trigeminal neuralgia secondary to trigeminal schwannoma. Magnetic resonance imaging of the brain showed a large bilobed cystic/solid mass primarily in the cerebellopontine angle cistern, with extension into the left middle cranial fossa, Meckel cave, and left cavernous sinus. Following surgical excision, histopathology revealed the tumor to be an RCC infiltrating into the trigeminal nerve fascicles. Further imaging and investigation revealed widespread metastasis to the vertebral bodies and long bones. Metastatic RCC to the trigeminal nerve is rare. Despite the development of more effective treatment modalities, the prognosis of metastatic RCC remains poor. To our knowledge, this is the first reported case of RCC metastasizing to the trigeminal nerve fascicles.

Endoscopic Endonasal Transsphenoidal Resection for Pituitary Apoplexy during the Third Trimester of Pregnancy.

Pituitary apoplexy is an uncommon phenomenon typically characterized by vascular insufficiency or acute hemorrhage into a pituitary adenoma. The overall incidence of pituitary apoplexy ranges between 1 and 25% of all pituitary adenomas. With the widespread use of MRI technology, the diagnosis of asymptomatic intratumoral hemorrhage is closer to 10%. The authors report a case of a 27-year-old female in her 36th week of pregnancy who presented with severe onset headache and acute left-sided vision loss. MRI of the brain revealed a large hemorrhagic mass occupying the sella turcica. The patient underwent an emergent endoscopic endonasal transsphenoidal resection for pituitary apoplexy. Postoperatively, the patient's neurologic deficit resolved. Minimally invasive endoscopic endonasal transsphenoidal resection of pituitary apoplexy can be safely utilized in third trimester pregnant women presenting with acute severe neurologic deficits.

Therapeutic decision making in patients with newly diagnosed low grade glioma.

OPINION STATEMENT: Low grade gliomas (LGG) encompass primary brain tumors that are typically well-differentiated and do not exhibit frankly malignant histologic features. These tumors can be further classified by their cellular morphology (eg, oligodendroglioma, pilocytic astrocytoma, etc), which does convey prognostic and therapeutic implications. Typically, low grade gliomas convey an overall better prognosis for patients as opposed to the higher grade primary brain tumors. Surgery for low grade gliomas and timing of such intervention remains controversial. Maximal resection of these tumors appears to prolong progression free survival. Advanced surgical techniques, including language mapping and awake craniotomies, have been shown to decrease morbidity associated with resection of lesions in eloquent areas of the brain. Radiation therapy has been proven effective in increasing time to progression in LGG, and emerging data support a role for combined modality therapy incorporating chemotherapy. Postoperative RT has been shown to have significant benefits with regards to progression free survival. Recent advances in molecular genetic markers, including the combined loss of chromosome arms 1p and 19q, and the mutation of the isocitrate dehydrogenase gene (IDH1/IDH2) have allowed for increased accuracy of predicting susceptibility to chemotherapeutic agents, as well as having some role in determining prognosis. PCV and temozolomide chemotherapy have both been studied when assessing progression free survival for LGG patients. Approaching patients with LGGs can be somewhat daunting given the lack of Class I evidence based protocols. However, significant evidence is now mounting to suggest early, maximal surgical excision; followed by fractionated RT will be the mainstays of treatment. Clearly, additional evidence is also mounting for the addition of chemotherapy in the treatment paradigm for patients with LGGs.

A novel sling technique for microvascular decompression of a rare anomalous vertebral artery causing cervical radiculopathy.

Cervical radiculopathy secondary to compression from congenital anomalous vertebral arteries (VAs) is a known entity. Patients present with a variety of symptoms ranging from upper-extremity numbness to true occipital neuralgia. Treatment options for extracranial tortuous VAs include conservative management or some form of surgical microvascular decompression (MVD). The authors report on a patient with a congenital anomalous VA loop causing cervical nerve root compression. Successful MVD was conducted with relief of the patient's symptoms. A novel sling technique was used for mobilization of the VA. To the authors' knowledge, this is the first MVD described utilizing this technique.

Comparison of postoperative values for C-reactive protein in minimally invasive and open lumbar spinal fusion surgery.

BACKGROUND: A major purported benefit of minimally-invasive spinal surgery (MIS) technique is less disruption of paraspinal soft tissues, but there is little quantifiable evidence of this in medical literature. Postoperative C-reactive protein (CRP) levels been shown to become more significantly elevated with larger surgical procedures, and this may allow for more measurable appreciation of any benefits of MIS verses open spinal surgery. METHODS: CRP values were measured prior to and at multiple time points following surgery in patients undergoing posterior spinal fusion using both open and minimally invasive techniques. RESULTS: Peak postoperative CRP was significantly lower in the 35 single-level minimally invasive procedures compared with the 11 single-level open procedures (13.5 vs. 21.3, P <0.01) and lower in the 12 two-level minimally invasive surgeries compared with 16 two-level open procedures (20.5 vs. 31.8, P <0.01). CONCLUSIONS: MIS lumbar fusion is associated with a lower peak in postoperative CRP compared with open surgery. This appears to support the notion that minimally invasive spine surgery technique leads to a measurable reduction in paraspinal soft tissue destruction mediated inflammation in the immediate postoperative period.

PDGFRA gene rearrangements are frequent genetic events in PDGFRA-amplified glioblastomas.

Gene rearrangement in the form of an intragenic deletion is the primary mechanism of oncogenic mutation of the epidermal growth factor receptor (EGFR) gene in gliomas. However, the incidence of platelet-derived growth factor receptor-α (PDGFRA) gene rearrangement in these tumors is unknown. We investigated the PDGFRA locus in PDGFRA-amplified gliomas and identified two rearrangements, including the first case of a gene fusion between kinase insert domain receptor (KDR) (VEGFRII) and the PDGFRA gene, and six cases of PDGFRA(Δ8, 9), an intragenic deletion rearrangement. The PDGFRA(Δ8, 9) mutant was common, being present in 40% of the glioblastoma multiformes (GBMs) with PDGFRA amplification. Tumors with these two types of PDGFRA rearrangement displayed histologic features of oligodendroglioma, and the gene products of both rearrangements showed constitutively elevated tyrosine kinase activity and transforming potential that was reversed by PDGFR blockade. These results suggest the possibility that these PDGFRA mutants behave as oncogenes in this subset of gliomas, and that the prevalence of such rearrangements may have been considerably underestimated.

Glioblastoma subclasses can be defined by activity among signal transduction pathways and associated genomic alterations.

BACKGROUND: Glioblastoma multiforme (GBM) is an umbrella designation that includes a heterogeneous group of primary brain tumors. Several classification strategies of GBM have been reported, some by clinical course and others by resemblance to cell types either in the adult or during development. From a practical and therapeutic standpoint, classifying GBMs by signal transduction pathway activation and by mutation in pathway member genes may be particularly valuable for the development of targeted therapies. METHODOLOGY/PRINCIPAL FINDINGS: We performed targeted proteomic analysis of 27 surgical glioma samples to identify patterns of coordinate activation among glioma-relevant signal transduction pathways, then compared these results with integrated analysis of genomic and expression data of 243 GBM samples from The Cancer Genome Atlas (TCGA). In the pattern of signaling, three subclasses of GBM emerge which appear to be associated with predominance of EGFR activation, PDGFR activation, or loss of the RAS regulator NF1. The EGFR signaling class has prominent Notch pathway activation measured by elevated expression of Notch ligands, cleaved Notch receptor, and downstream target Hes1. The PDGF class showed high levels of PDGFB ligand and phosphorylation of PDGFRbeta and NFKB. NF1-loss was associated with lower overall MAPK and PI3K activation and relative overexpression of the mesenchymal marker YKL40. These three signaling classes appear to correspond with distinct transcriptomal subclasses of primary GBM samples from TCGA for which copy number aberration and mutation of EGFR, PDGFRA, and NF1 are signature events. CONCLUSIONS/SIGNIFICANCE: Proteomic analysis of GBM samples revealed three patterns of expression and activation of proteins in glioma-relevant signaling pathways. These three classes are comprised of roughly equal numbers showing either EGFR activation associated with amplification and mutation of the receptor, PDGF-pathway activation that is primarily ligand-driven, or loss of NF1 expression. The associated signaling activities correlating with these sentinel alterations provide insight into glioma biology and therapeutic strategies.