Follow-up Brain Imaging Within 30 Days of Gamma-Knife Surgery for New Symptoms: Retrospective Analysis.

OBJECTIVE: Gamma Knife surgery is a complementary procedure to open microsurgery for several indications. However, posttreatment symptomatic complaints are common and often result in short-term follow-up imaging. Here we evaluate the efficacy of repeat brain imaging within 30 days of a Gamma Knife procedure by analyzing the frequency with which that imaging reveals addressable pathology. METHODS: All patients who underwent Gamma Knife treatments at our institution between January 2013 and August 2019 were retrospectively analyzed, and any patient who received imaging of the brain within 30 days for a symptomatic complaint was evaluated. RESULTS: Of the 956 Gamma Knife cases performed, 78 (8.2%) scans were performed within a 30-day time frame for symptomatic complaints. Of these, the most common complaint was headache (25%). Most images demonstrated no changes when compared with the treatment scan (68%) and there were no hemorrhages and only 1 stroke (<1%). Univariate analysis revealed that sex (P = 0.046), treatment volume (P < 0.001), and treatments for metastasis (P < 0.001) or glioma (P < 0.001) were associated with symptomatic complaints leading to imaging, but no factors were associated with higher rates of abnormal imaging. CONCLUSIONS: Gamma Knife therapy remains a safe treatment for multiple indications, but it is not risk free and acute symptomatic complaints are common. However, our data suggest that the need for reimaging within 30 days for symptomatic complaints is likely overestimated as obtained imaging does not usually show any change and the rate of significant complication is exceedingly low.

Multiple Simultaneous Mature Teratomas of the Spinal Cord in an Adult.

Teratomas of the spinal cord are rare tumors, particularly in adults, but there is an increasing body of literature documenting both their diagnosis and successful treatment with surgical resection. However, to date, the literature has largely characterized spinal teratomas as single solitary lesions. Here, we report on an adult patient who presented with signs of progressive lower extremity weakness. Imaging demonstrated two simultaneous lesions of the spine, an extramedullary lesion in the upper thoracic region and an intramedullary lesion in the mid-thoracic region. Both lesions were resected and pathologically determined to be mature spinal teratomas. To our knowledge, this is only the second report of this tumor presenting simultaneously at more than one location in the spine and the first time it has presented both as an intra-axial and extra-axial lesion. Our results suggest that the presence of more than one simultaneous lesion does not necessarily increase the risk of a more aggressive immature pathology.

Revision surgeries following vagus nerve stimulator implantation.

The vagus nerve stimulator (VNS) has been shown to provide a safe, albeit costly, treatment for intractable epilepsy. We aimed to analyze the incidence, timing, and clinical/demographic associations of revision surgery post-VNS implantation in epilepsy patients. The Thomson Reuters MarketScan database, containing data from 23-50million individuals, was used. Epilepsy patients receiving VNS implantations from 2003 to 2009 were identified by Current Procedural Terminology and International Classification Of Diseases Ninth Revision codes. Incidence and timing of subsequent implant-related surgeries were recorded. Events were described using time-to-event methodology, with Kaplan-Meier failure estimation/Cox proportional hazard models adjusted for clinical/demographic factors. In 1234 patients, average incidence of revision surgeries over 6years of follow-up were <1%, <3%, 4-10%, and <1% for VNS electrode revision, battery revision/removal, battery replacement/implantation, and infection washout, respectively. For electrode revision and battery revision/replacement, the incidence was higher in the first year and for battery replacement in later years. Age, sex, insurance type, or geographic region did not significantly impact event occurrence. Implant-related revision surgeries are rare. Some events occur more often in certain follow-up years than others; none are significantly impacted by age, sex, insurance type, or geographic region. The most common reason for revision was battery replacement several years after VNS placement.

Percutaneous CT-guided cordotomy for the treatment of pediatric cancer pain.

Percutaneous cordotomy using CT guidance has been shown to be a safe and effective means of reducing pain in adults with cancer in 2 large case series. Its effectiveness in pediatric patients, however, has not been reported. Here, the authors present a case of CT-guided percutaneous cordotomy being used effectively for the treatment of unilateral limb pain in a 9-year-old boy suffering from metastatic medulloblastoma. The efficacy and minimally invasive nature of this procedure support its use in selected pediatric cases.

Glioblastoma of the cerebellum in children: report of five cases and review of the literature.

PURPOSE: Cerebellar glioblastomas in children are rare. As a result, an optimal treatment strategy has not yet been identified. A review of the characteristics of the disease as well as the effectiveness of various therapeutic modalities would help in optimizing the treatment paradigm. METHODS: We performed a detailed clinical, radiographic, and pathologic retrospective review of five patients (three boys and two girls, average age at presentation 7.2 years (range, 3-14 years)) and surveyed the literature for an additional 55 cases. RESULTS: Computed tomography and magnetic resonance imaging usually revealed a large lesion with minimal edema, heterogeneous contrast enhancement, and a discrete border. Subtotal tumor resection was performed in two patients and gross total resection in three patients. Immunostaining of the tumor cells with antisera to glial fibrillary acidic protein and vimentin was variably positive. Adjuvant therapy included local radiation and chemotherapy in all followed patients. Tumor recurrence was seen in two patients. Patients were followed from 2 months to 3.5 years (mean, 12 months). Two patients were dead at last follow-up with a mean survival of 9.5 months. CONCLUSIONS: The prognosis for pediatric patients with cerebellar glioblastomas is dismal, even when compared to adult counterparts or other malignant posterior fossa tumors in children. Cerebellar glioblastomas have a tendency to recur and disseminate despite treatment with surgery, chemotherapy, and radiation. The poor outcomes seen with this tumor suggest that the optimal treatment strategy has yet to be elucidated and much work needs to be done.

Neurosurgical complications of left ventricular assist devices in children.

OBJECT: Left ventricular assist devices (LVADs) are continuous or pulsatile flow devices that could potentially be life-saving measures for patients with end-stage heart failure. These devices have clear advantages over extracorporeal membrane oxygenation (ECMO) and are often used in adults. They are only recently being commonly used in the pediatric age group. As the use of LVADs becomes more mainstream in children, it is important to determine the complication profile associated with these devices. Furthermore, with the increasing application of LVADs in children, pediatric neurosurgeons are seeing a correlative increase in associated neurological complications. In this study, the authors reviewed the incidence of neurological complications due to LVAD use in the pediatric age group and the role of neurosurgery in treatment. METHODS: The authors examined data regarding patients with LVADs from the Texas Children's Hospital Heart Center database (July 01, 2007, to June 30, 2011) and recorded neurological complications requiring neurosurgical consultation. They identified 2 children who underwent craniotomies during LVAD treatment. RESULTS: Intracranial hemorrhage occurred in 3 (6.5%) of the 46 patients treated with an LVAD at the authors' institution. Of these patients, 2 were treated with craniotomies for life-threatening intracranial hemorrhages. The 3 patients in the neurosurgical cohort presented with cerebral infarction, decreased level of consciousness, and/or seizure. At the last follow-up (286, 503, and 550 days), 1 patient (case 2) had no decline in neurological status, underwent a successful heart transplant, and was discharged home; 1 patient (case 1) died of refractory cardiac failure; and 1 patient (case 3) was on an LVAD for destination therapy (that is, the LVAD is not a bridge to transplantation but rather the final treatment). This patient was discharged from the hospital, but he died of overwhelming fungemia at 286 days while on VAD support. CONCLUSIONS: Intracranial hemorrhage is a serious and feared complication of LVAD treatment. While the surgical risk is substantial due to systemic anticoagulation and significant medical comorbidities, neurosurgical evacuation of hemorrhage plays an important life-saving role that can yield successful and acceptable outcomes.

Standing wave total internal reflection fluorescence microscopy to measure the size of nanostructures in living cells.

We present the first application of standing wave fluorescence microscopy (SWFM) to determine the size of biological nanostructures in living cells. The improved lateral resolution of less than 100 nm enables superior quantification of the size of subcellular structures. We demonstrate the ability of SWFM by measuring the diameter of biological nanotubes (membrane tethers formed between cells). The combination of SWFM with total internal reflection (TIR), referred to as SW-TIRFM, allows additional improvement of axial resolution by selective excitation of fluorescence in a layer of about 100 nm.