Resolution of Middle Fossa Arachnoid Cyst after Minor Head Trauma - Stages of Resolution on MRI: Case Report and Literature Review.

Arachnoid cysts (ACs) are frequently encountered in pediatric neurosurgical practice. Their natural history and optimum treatment are not well determined. The authors describe a resolution of asymptomatic middle fossa AC after trivial head trauma in a 7-year-old child. Intracystic bleeding was noticed on interval MRI. Serial MRI follow-up demonstrates stages of resolution of the AC that did not require surgical intervention. Few cases of nonsurgical AC disappearance have been reported, much fewer with trauma as a triggering factor. Here, we present the stages of resolution in images.

Atypical Teratoid Rhabdoid Tumor Diagnosis after Partial Resection of Dysembryoplastic Neuroepithelial Tumor: Case Report and Review of the Literature.

Dysembryoplastic neuroepithelial tumors (DNETs) are generally considered benign, slow-growing epilepsy-associated lesions. While rare cases of malignant transformation of DNET to high-grade glial tumors have been reported, to our knowledge there have been no reports of transformation/emergence of DNET to atypical teratoid rhabdoid tumor (AT/RT), a highly aggressive embryonal brain tumor. Here, we report the case of an 8-year-old boy who presented with an incidental finding of a small right insular lesion which grew slowly over 3 years. The patient first underwent surgery with subtotal tumor resection at age 11. Pathology was consistent with DNET. Following surgery, further tumor growth was evident, requiring fractionated radiotherapy and eventually chemotherapy, but continued tumor growth was witnessed. Three years after radiation, imaging showed dramatic further tumor growth, and the patient underwent a second debulking surgery. The pathology revealed a malignant tumor with BAF47-negative cells, suggestive of AT/RT. This report adds to our knowledge about the poorly understood behavior and natural history of DNETs and emphasizes the importance of lifelong clinical and neuroimaging follow-up of these lesions.

Management of infiltrating spinal epidural angiolipoma.

Angiolipomas of the spine are rare benign tumors commonly presenting with compressive myelopathy. The present report describes a case of spinal angiolipoma with thoracic mediastinal extension in a 50-year-old woman. She presented with a long-standing history of mid-back pain with progressive lower extremities weakness. An MRI showed a heterogeneously enhancing mass located in the posterior epidural space of the thoracic spine with mediastinal extension. Histopathological examination demonstrated features consistent with spinal angiolipoma. This report emphasizes the diagnosis and therapeutic management options of infiltrating spinal angiolipomas.

The role of drebrin in glioma migration and invasion.

Glioblastoma (GBM) is the most common primary brain tumor in adults. Despite current advances in therapy consisting of surgery followed by chemotherapy and radiation, the overall survival rate still remains poor. Therapeutic failures are partly attributable to the highly infiltrative nature of tumor adjacent to normal brain parenchyma. Recently, evidence is mounting to suggest that actin cytoskeleton dynamics are critical components of the cell invasion process. Drebrin is an actin-binding protein involved in the regulation of actin filament organization, and plays a significant role in cell motility; however, the role of drebrin in glioma cell invasiveness has not yet been fully elucidated. Therefore, this study was aimed to clarify the role of drebrin in glioma cell morphology and cell motility. Here we show that drebrin is expressed in glioma cell lines and in operative specimens of GBM. We demonstrate that stable overexpression of drebrin in U87 cells leads to alterations in cell morphology, and induces increased invasiveness in vitro while knockdown of drebrin in U87 cells by small interfering RNA (siRNA) decreases invasion and migration. In addition, we show that depletion of drebrin by siRNA alters glioma cell morphology in A172 GBM cell line. Our results suggest that drebrin contributes to the maintenance of cell shape, and may play an important role in glioma cell motility.

A Report of Two Simultaneous Different Skull Vault Boney Pathologies: An Extremely Rare Clinical Scenario.

Primary calvarial boney tumors are generally rare in clinical practice. Multiple primary skull neoplasms are less frequent, typically associated with genetic disorders or familial syndromes. Sporadic cases of multiple skull tumors are exceptionally rare. We present a unique scenario of a 32-year-old female patient who had two right-sided skull vault lesions, one located over the right parietal area and the other in the right retro-auricular region. The lesions exhibited different behaviors over several years. The workup revealed that the two skull lesions were of two pathologies. The standard academic approach for clinical analysis attributes the symptoms often to one pathological process until proven otherwise. This case highlights the significance of expanding the differential diagnoses and incites clinicians to consider multiple pathologies in specific clinical settings.

Descriptive epidemiological analysis, MRI signals intensity and histopathological correlations of meningiomas.

OBJECTIVES: To present our experience in operated meningioma cases regarding their prevalence, anatomical location, multiplicity, presenting signs and symptoms, and the possible correlation between MRI signal intensity and histological grades to set criteria for radio-pathological diagnosis. METHODS: In this retrospective study, operated meningioma cases in the Department of Neurosurgery, Jordan University Hospital (JUH), Amman, Jordan between January 1997 and January 2007 were reviewed. Our study included 90 cases, and their medical records, histopathological reports, and neuroimages were analyzed thoroughly. RESULTS: Meningioma was more common in females than males with a ratio of 2.2:1. Para-sagittal meningiomas were the most common (23.3%). Multiple intracranial meningiomas were found in 4.4% of the cases. Most cases were of benign histopathology and exhibited iso-intense signals on T1 and T2, and appeared with hyper-intense signals on FLAIR with vivid enhancement. CONCLUSION: The prevalence of meningioma among genders and its anatomical location at JUH corresponds to the published medical literature worldwide. There was no correlation between signal intensities (as seen on T1WI, T2WI, and FLAIR sequences), enhancement pattern on one side, and histological grades on the other side.

Testing the effectiveness and the contribution of experimental supercharge (reversed) end-to-side nerve transfer.

OBJECTIVE: Supercharge end-to-side (SETS) transfer, also referred to as reverse end-to-side transfer, distal to severe nerve compression neuropathy or in-continuity nerve injury is gaining clinical popularity despite questions about its effectiveness. Here, the authors examined SETS distal to experimental neuroma in-continuity (NIC) injuries for efficacy in enhancing neuronal regeneration and functional outcome, and, for the first time, they definitively evaluated the degree of contribution of the native and donor motor neuron pools. METHODS: This study was conducted in 2 phases. In phase I, rats (n = 35) were assigned to one of 5 groups for unilateral sciatic nerve surgeries: group 1, tibial NIC with distal peroneal-tibial SETS; group 2, tibial NIC without SETS; group 3, intact tibial and severed peroneal nerves; group 4, tibial transection with SETS; and group 5, severed tibial and peroneal nerves. Recovery was evaluated biweekly using electrophysiology and locomotion tasks. At the phase I end point, after retrograde labeling, the spinal cords were analyzed to assess the degree of neuronal regeneration. In phase II, 20 new animals underwent primary retrograde labeling of the tibial nerve, following which they were assigned to one of the following 3 groups: group 1, group 2, and group 4. Then, secondary retrograde labeling from the tibial nerve was performed at the study end point to quantify the native versus donor regenerated neuronal pool. RESULTS: In phase I studies, a significantly increased neuronal regeneration in group 1 (SETS) compared with all other groups was observed, but with modest (nonsignificant) improvement in electrophysiological and behavioral outcomes. In phase II experiments, the authors discovered that secondary labeling in group 1 was predominantly contributed from the donor (peroneal) pool. Double-labeling counts were dramatically higher in group 2 than in group 1, suggestive of hampered regeneration from the native tibial motor neuron pool across the NIC segment in the presence of SETS. CONCLUSIONS: SETS is indeed an effective strategy to enhance axonal regeneration, which is mainly contributed by the donor neuronal pool. Moreover, the presence of a distal SETS coaptation appears to negatively influence neuronal regeneration across the NIC segment. The clinical significance is that SETS should only employ synergistic donors, as the use of antagonistic donors can downgrade recovery.

Management of peripheral nerve sheath tumors: 17 years of experience at Toronto Western Hospital.

OBJECTIVE A surgical series of 201 benign and malignant peripheral nerve sheath tumors (PNSTs) was assessed to characterize the anatomical and clinical presentation of tumors and identify predictors of neurological outcome, recurrence, and extent of resection. METHODS All surgically treated PNSTs from the Division of Neurosurgery at Toronto Western Hospital from 1993 to 2010 were reviewed retrospectively. Data were collected on patient demographics, clinical presentation, surgical technique, extent of resection, postoperative neurological outcomes, and recurrence. RESULTS One hundred seventy-five patients with 201 tumors had adequate follow-up for analysis. There were 182 benign and 19 malignant PNSTs. Of the benign lesions, 133 were schwannomas, 21 of which were associated with a diagnosis of schwannomatosis. There were 49 neurofibromas, and 26 were associated with neurofibromatosis Type 1 (NF1). Patients presenting with schwannomas were significantly older than those with neurofibromas. Schwannomas were more readily resected than neurofibromas, with the extent of resection of the former influenced by tumor location. Patients with benign PNSTs typically presented with a painful mass and less frequently with motor deficits. The likelihood of worsened postoperative motor function was decreased in patients with fully resected tumors or preoperative deficits. Recurrence of schwannomas and neurofibromas were seen more frequently in patients diagnosed with NF3 and NF1, respectively. Subtotal resection was associated with the increased recurrence of all benign lesions. CONCLUSIONS Outcomes following resection of benign PNSTs depend on tumor histopathology, tumor location, and genetic predisposition syndrome. Gross-total resection should be attempted for benign lesions where possible. The management of malignant PNSTs remains challenging, requiring a multimodal approach.

Medulloblastoma invading the transverse sinus: case report.

Medulloblastoma is a highly malignant brain tumor of childhood. Although craniospinal dissemination within the subarachnoid space is common, invasion of the dural sinuses is rare. Here, the authors report on a 15-year-old girl who presented with a right cerebellar mass, obstructive hydrocephalus, and radiographic evidence of tumor invasion into the right transverse-sigmoid sinus junction. The patient underwent posterior fossa craniotomy, gross-total resection of the intraparenchymal component of the right cerebellar tumor, and coagulation of the tumor invading the transverse sinus. After pathological confirmation of anaplastic medulloblastoma, the patient underwent craniospinal radiation therapy and high-dose chemotherapy. At 2 years posttreatment, the child was neurologically intact with no radiographic evidence of residual disease or recurrence. The implications for disease prognosis and management are discussed.