Syringosubarachnoid shunting using a myringotomy tube.

BACKGROUND: Syringomyelia results from obstruction of cerebrospinal fluid (CSF) flow due to a multitude of causes. Often symptoms of pain, weakness, and sensory disturbance are progressive and require surgical treatment. We present here a rare technique for syringosubarachnoid shunting. CASE DESCRIPTION: We present the case of a 38-year-old male who suffered a traumatic cervical spinal cord injury due to a motor vehicle accident. With progressive pain and motor decline, a magnetic resonance imaging was obtained and showed a new syrinx extending cervical multiple segments. A unique surgical procedure using a myringotomy tube to shunt CSF into the subarachnoid space was employed in this case. The patient's examination stabilized postoperatively, and at 2 months and 6 months follow-up visits, his strength and sensation continued to improve. CONCLUSION: We used a myringotomy tube for syringosubarachnoid shunting for the surgical management of a posttraumatic syrinx with good results. This technique minimizes suturing and may minimize shunt-related complications.

Treatment of Costal Osteochondroma Causing Spinal Cord Compression by Costotransversectomy: Case Report and Review of the Literature.

In laminectomies for costal osteochondroma causing spinal cord compression, visualization of the extraforaminal part of the tumor is limited. The authors describe using a costotransversectomy to resolve spinal cord compression by a costal osteochondroma invading through the neural foramen. A 21-year-old woman with hereditary multiple exostoses presented with hand numbness and progressive neck and upper back pain. Plain radiographs identified a large lesion of the T2 and T3 pedicles, with encroachment on the T2-3 neural foramen causing ~50% spinal canal stenosis. Costotransversectomy was performed to resect the cartilaginous portions of the osteochondroma, debulk the mass, and decompress the spinal canal. A mass of mature bone was left, but no appreciable cartilaginous tumor. At five-year follow-up, the patient had improvement of neck pain, no new neurological deficits. a stable residual mass, and no new osteochondromas, indicating that appropriate surgical management can yield good results and no evidence of recurrence.

The Fate of Type II Odontoid Fractures after Posterior Atlantoaxial Fusion: Where Does Healing Occur?

BACKGROUND: Anderson and D'Alonzo type II odontoid fractures often require surgical intervention. Our goal was to understand the pattern of healing in patients who had a posterior atlantoaxial fusion for a type II odontoid fracture. METHODS: We conducted a retrospective study of patients who underwent posterior atlantoaxial instrumentation and fusion for a type II odontoid fracture at our institution between 1987 and 2011. Patients who had fusion evaluation by computed tomography (CT) scan ≥3 months after surgery were included. Surgical technique included placement of a posterior bone graft with transarticular screws, C1 lateral mass and C2 pars/pedicle screw construct, or a combination of screw fixation techniques. Postoperative CT scans were reviewed to determine the site where fusion occurred. RESULTS: Sixty-four patients underwent posterior atlantoaxial instrumentation and fusion for type II odontoid fractures, 12 of whom had fusion evaluation by CT scan. A total of 11 of 12 patients had fusion across the fracture site, 2 across the C1-C2 joint, and 11 at the posterior graft site. All 12 patients had at least one site of fusion. CONCLUSIONS: There is a high rate of fusion across the fracture site of a type II odontoid fracture after posterior atlantoaxial fixation. In young patients with acute type II fractures who are not candidates for anterior screw fixation, posterior atlantoaxial instrumentation without fusion may be sufficient for fracture healing, thus allowing for the possibility of implant removal and preservation of C1-C2 motion.

Preoperative dynamic contrast-enhanced MRI correlates with molecular markers of hypoxia and vascularity in specific areas of intratumoral microenvironment and is predictive of patient outcome.

BACKGROUND: Measures of tumor vascularity and hypoxia have been correlated with glioma grade and outcome. Dynamic contrast-enhanced (DCE) MRI can noninvasively map tumor blood flow, vascularity, and permeability. In this prospective observational cohort pilot study, preoperative imaging was correlated with molecular markers of hypoxia, vascularity, proliferation, and progression-free and overall patient survival. METHODS: Pharmacokinetic modeling methods were used to generate maps of tumor blood flow, extraction fraction, permeability-surface area product, transfer constant, washout rate, interstitial volume, blood volume, capillary transit time, and capillary heterogeneity from preoperative DCE-MRI data in human glioma patients. Tissue was obtained from areas of peritumoral edema, active tumor, hypoxic penumbra, and necrotic core and evaluated for vascularity, proliferation, and expression of hypoxia-regulated molecules. DCE-MRI parameter values were correlated with hypoxia-regulated protein expression at tissue sample sites. RESULTS: Patient survival correlated with DCE parameters in 2 cases: capillary heterogeneity in active tumor and interstitial volume in areas of peritumoral edema. Statistically significant correlations were observed between several DCE parameters and tissue markers. In addition, MIB-1 index was predictive of overall survival (P = .044) and correlated with vascular endothelial growth factor expression in hypoxic penumbra (r = 0.7933, P = .0071) and peritumoral edema (r = 0.4546). Increased microvessel density correlated with worse patient outcome (P = .026). CONCLUSIONS: Our findings suggest that DCE-MRI may facilitate noninvasive preoperative predictions of areas of tumor with increased hypoxia and proliferation. Both imaging and hypoxia biomarkers are predictive of patient outcome. This has the potential to allow unprecedented prognostic decisions and to guide therapies to specific tumor areas.

Functional genomics identifies drivers of medulloblastoma dissemination.

Medulloblastomas are malignant brain tumors that arise in the cerebellum in children and disseminate via the cerebrospinal fluid to the leptomeningeal spaces of the brain and spinal cord. Challenged by the poor prognosis for patients with metastatic dissemination, pediatric oncologists have developed aggressive treatment protocols, combining surgery, craniospinal radiation, and high-dose chemotherapy, that often cause disabling neurotoxic effects in long-term survivors. Insights into the genetic control of medulloblastoma dissemination have come from transposon insertion mutagenesis studies. Mobilizing the Sleeping Beauty transposon in cerebellar neural progenitor cells caused widespread dissemination of typically nonmetastatic medulloblastomas in Patched(+/-) mice, in which Shh signaling is hyperactive. Candidate metastasis genes were identified by sequencing the insertion sites and then mapping these sequences back to the mouse genome. To determine whether genes located at transposon insertion sites directly caused medulloblastomas to disseminate, we overexpressed candidate genes in Nestin(+) neural progenitors in the cerebella of mice by retroviral transfer in combination with Shh. We show here that ectopic expression of Eras, Lhx1, Ccrk, and Akt shifted the in vivo growth characteristics of Shh-induced medulloblastomas from a localized pattern to a disseminated pattern in which tumor cells seeded the leptomeningeal spaces of the brain and spinal cord.

Technique for decompressive craniectomy using Seprafilm as a dural substitute and anti-adhesion barrier.

Surgeons in abdominal and gynecological fields have pioneered the use of Seprafilm (a chemically modified sodium hyaluronate/carboxymethylcellulose absorbable adhesion barrier, Genzyme Biosurgery, Cambridge, MA, USA) to prevent adhesion but its use outside these specialties is not well documented. The authors have used Seprafilm for craniectomy closure in several patients as a dural substitute and anti-adhesion barrier. During emergent craniectomy, the dura mater is reapproximated and a layer of Seprafilm is placed over the dura as an onlay and anti-adhesion barrier. During subsequent surgery for bone flap replacement, dissection between the dural plane and overlying tissues has been completed easily. There has been minimal adhesion to the underlying Seprafilm/dural layer. The Seprafilm has been incorporated into the surrounding dural plane. No postoperative complications have been noted. Seprafilm's anti-adhesive properties and biodegradable characteristics make it useful as a dural onlay for craniectomy in which a second surgery is planned.

Ganglion cyst of the temporomandibular joint with intracranial extension in a patient presenting with seventh cranial nerve palsy.

Ganglion cysts arising from the temporomandibular joint are rare entities that often present with swelling and minimal to no pain in the preauricular region. To the authors' knowledge, a temporomandibular joint ganglion cyst occurring with acute facial nerve palsy and intracranial extension has never been reported. The patient in the current case initially underwent treatment for Bell palsy and then draining of the cyst at an outside hospital with no relief of symptoms. Repeat MR imaging showed an increase in the size of the cystic, enhancing, middle fossa lesion measuring 4 cm. Resection of the lesion was undertaken using a middle fossa approach. After a satisfactory surgical decompression, the patient demonstrated a significant recovery in her facial palsy over a 3-month period of time. This case presents new clinical and radiographic findings associated with these lesions.

Management considerations and strategies to avoid complications associated with the thoracoscopic approach for corpectomy.

The thoracoscopic approach to the anterior spine is a practical and valuable means of approaching ventral spinal lesions but demands advanced technical skills and fine hand-eye coordination that is usually acquired with experience. A mutual understanding of all the ventilatory and surgical steps allows for an organized orchestration between the anesthesiologist and surgeon, which ultimately helps minimize potential complications. Despite a concerted effort by all involved to avoid risks, thoracoscopic surgery is associated with complications for which the surgical team should be cognizant. In this paper, the authors detail the operative technique of vertebral corpectomy and interbody fusion via the thoracoscopic approach for the treatment of ventral spinal pathology involving the thoracic and lower lumbar spine, discuss complications known to occur with the thoracoscopic approach, and present means to help avoid them.

Avoiding pitfalls in anterior screw fixation for type II odontoid fractures.

Anterior screw fixation of Type II odontoid fractures provides immediate stabilization of the cervical spine while preserving C1-2 motion. This technique has a high fusion rate, but can be technically challenging. The authors identify key points that should be taken into account to maximize the chance for a favorable outcome. Keys to success include proper patient and fracture selection, identification of suitable screw entry point and correct screw trajectory, achieving bicortical purchase, and placing 2 screws when feasible and applicable. The authors review the operative technique and present guidance on appropriate patient selection and common pitfalls in anterior screw fixation, with strategies for avoiding complications.

Cystic granular cell tumor mimicking Rathke cleft cyst.

Symptomatic granular cell tumors of the neurohypophysis are a rarely reported entity. To the authors' knowledge, they report the first fully described case of a symptomatic granular cell tumor with a large cystic component. A 31-year-old woman presented with headaches and visual complaints with imaging findings confirming a cystic sellar and suprasellar mass. The lesion was resected, and histological examination confirmed the diagnosis. The literature has shown that granular cell tumors are rarely reported as being symptomatic but may actually be a fairly common finding in autopsy studies. The authors review the literature with a specific focus on radiographic findings in patients with symptomatic granular cell tumors.

Pleomorphic liposarcoma originating from intracranial dura mater.

Liposarcomas are the most common soft tissue sarcoma found in adults; however, disease involving or spreading to the head and neck is extremely rare. To our knowledge, we present the first case of primary pleomorphic liposarcoma originating intracranially. A 56-year-old man presented with new weakness and imaging findings confirming a right frontal mass. After resection, histological analysis confirmed the diagnosis of pleomorphic liposarcoma. The patient underwent radiation treatment and surveillance imaging, which revealed no other areas of disease. Results reported previously in the literature indicate that pleomorphic liposarcoma is very aggressive in nature. The authors review the few cases of primary or metastatic pleomorphic liposarcoma that have been reported involving the head.

Parafalcine lesions in the cancer patient: diagnostic dilemma--meningioma or metastatic lesion?

The authors present two cases that illustrate the difficulty in radiographically distinguishing between meningioma and metastatic lesions in patients with known cancer, especially with a parafalcine tumor location. The first patient with known metastatic prostate cancer had imaging studies suggestive of a parafalcine meningioma, but after surgical resection the lesion was found to be histologically consistent with metastatic disease. Conversely, the second patient was thought to have a metastatic breast cancer lesion in the parafalcine region. This presumptive diagnosis based on imaging findings led the patient to undergo radiosurgery treatment; however, the lesion grew over a several-month course and was eventually resected. The pathological analysis revealed that the tumor was, in fact, a meningioma. Using these cases, as well as an extensive review of the literature, the authors highlight the difficulty in making accurate radiographic diagnosis of dural-based lesions, especially in the parafalcine location, where meningiomas are commonly found but can have multiple entities mimicking their presentation. Caution must be used in managing patients with presumed parafalcine meningiomas or metastatic disease that have no histological diagnosis.

An animal model of capsular infarct: endothelin-1 injections in the rat.

In this study stereotaxic injections of the vasoconstrictive peptide endothelin-1 (ET-1) were used to create infarcts in the white matter of the internal capsule underlying sensorimotor cortex in rats. Resulting deficits were assessed using established sensorimotor tests conducted on each rat before and after the ET-1-induced infarct. After a 14-day survival period, histological examination revealed tissue necrosis and demyelination in the infarcted white matter of ET-1-injected rats, but not saline-injected control rats. Infarcts resulted in measurable sensorimotor deficits in rats that received ET-1 injections. The same sensorimotor tests showed no deficits in surgical-control rats. The present model of white matter infarct should be valuable in examining the underlying mechanisms of subcortical ischemic stroke and to evaluate potential therapeutic interventions.