23 research outputs found

    Hypothalamic deep brain stimulation reduces weight gain in an obesity-animal model. PLoS One 7

    Get PDF
    Abstract Prior studies of appetite regulatory networks, primarily in rodents, have established that targeted electrical stimulation of ventromedial hypothalamus (VMH) can alter food intake patterns and metabolic homeostasis. Consideration of this method for weight modulation in humans with severe overeating disorders and morbid obesity can be further advanced by modeling procedures and assessing endpoints that can provide preclinical data on efficacy and safety. In this study we adapted human deep brain stimulation (DBS) stereotactic methods and instrumentation to demonstrate in a large animal model the modulation of weight gain with VMH-DBS. Female Gö ttingen minipigs were used because of their dietary habits, physiologic characteristics, and brain structures that resemble those of primates. Further, these animals become obese on extra-feeding regimens. DBS electrodes were first bilaterally implanted into the VMH of the animals (n = 8) which were then maintained on a restricted food regimen for 1 mo following the surgery. The daily amount of food was then doubled for the next 2 mo in all animals to produce obesity associated with extra calorie intake, with half of the animals (n = 4) concurrently receiving continuous low frequency (50 Hz) VMH-DBS. Adverse motoric or behavioral effects were not observed subsequent to the surgical procedure or during the DBS period. Throughout this 2 mo DBS period, all animals consumed the doubled amount of daily food. However, the animals that had received VMH-DBS showed a cumulative weight gain (6.160.4 kg; mean 6 SEM) that was lower than the nonstimulated VMH-DBS animals (9.461.3 kg; p,0.05), suggestive of a DBS-associated increase in metabolic rate. These results in a porcine obesity model demonstrate the efficacy and behavioral safety of a low frequency VMH-DBS application as a potential clinical strategy for modulation of body weight

    Learning curves of open and endoscopic fetal spina bifida closure: a systematic review and meta-analysis

    Get PDF
    OBJECTIVES: The Management Of Myelomeningocele Study (MOMS) trial demonstrated the safety and efficacy of open fetal surgery for spina bifida (SB). Recently developed alternative techniques may reduce maternal risks yet should do without compromising on fetal neuroprotective effects. We aimed to assess the learning curve of different fetal SB closure techniques. METHODS: We searched Medline, Web of Science, Embase, Scopus and Cochrane databases and the grey literature to identify relevant articles without language restriction from January 1980 until October 2018. We systematically reviewed and selected studies reporting all consecutive procedures and with a postnatal follow-up ≥12 months. They also had to report outcome variables necessary to measure the learning curve defined by fetal safety and efficacy. Two independent authors retrieved the data, assessed the quality of the studies and categorized observations into blocks of 30 patients. For meta-analysis, data were pooled using a random-effect model when heterogeneous. To measure the learning curve, we used two complementary methods. With the group splitting method, competency was defined when the procedure provided comparable results to the MOMS trial for 12 outcome variables representative for (1) the immediate surgical outcome, (2) short-term neonatal neuroprotection and (3) long-term neuroprotection at ≥12 months. Then, when the patients' raw data were available, we performed cumulative sum (CUSUM) analysis based on a composite binary outcome defining a successful surgery. It combined four clinically relevant variables for safety (fetal death within 7 days) and for efficacy (neuroprotection at birth). RESULTS: We included 17/6024 (0.3%) studies with low and moderate risks of bias. Fetal SB closure was performed via standard-hysterotomy (n=11), mini-hysterotomy (n=1) or fetoscopy [exteriorized-uterus single-layer (n=1), percutaneous single-layer (n=3) or percutaneous two-layer closure (n=1)]. Only outcomes for the standard-hysterotomy could be meta-analyzed. Overall, outcomes significantly improved with experience. Competency was reached after 35 consecutive cases for standard-hysterotomy and was predicted to be achieved after ≥57 cases for mini-hysterotomy and ≥56 for percutaneous two-layer fetoscopy. For percutaneous and uterus-exteriorized single-layer fetoscopy, competency was not respectively reached by cases 81 and 28 available for analysis. CONCLUSIONS: The number of cases operated correlates with the outcome of SB fetal closure and ranges from 35 cases for standard-hysterotomy to ≥56-57 cases for minimally invasive modifications. Our observations provide important information for institutions eager to establish a new fetal center, develop a new technique or train their team, and inform referring clinicians, potential patients and third-parties

    Radiosurgery and stereotactic radiotherapy for intracranial meningiomas

    No full text

    Radiation options for high-grade gliomas

    No full text
    Radiotherapy has become a part of the standard treatment of high-grade gliomas. Studies have shown that high-dose radiation results in more effective tumor control but at the cost of radionecrosis and other radiation-related side effects. Despite advancing techniques in stereotaxy and precise radiotherapy delivery techniques, studies published for stereotactic radiosurgical treatment of high-grade gliomas have not been unanimous, with large trials showing no survival benefit compared with conventional conformal radiotherapy. New imaging modalities have been studied with the hope to improve accuracy in the planning of radiosurgical treatments. However, further large scale studies are needed to confirm these results

    Brain Ischemia in Head Injury

    No full text

    Stereotactic Radiosurgery for Postoperative Metastatic Surgical Cavities: A Critical Review and International Stereotactic Radiosurgery Society (ISRS) Practice Guidelines.

    No full text
    The purpose of this critical review is to summarize the literature specific to single-fraction stereotactic radiosurgery (SRS) and multiple-fraction stereotactic radiation therapy (SRT) for postoperative brain metastases resection cavities and to present practice recommendations on behalf of the ISRS. The Medline and Embase databases were used to apply the Preferred Reporting Items for Systematic Reviews and Meta-Analyses approach to search for manuscripts reporting SRS/SRT outcomes for postoperative brain metastases tumor bed resection cavities with a search end date of July 20, 2018. Prospective studies, consensus guidelines, and retrospective series that included exclusively postoperative brain metastases and had at minimum 100 patients were considered eligible. The Embase search revealed 157 manuscripts, of which 77 were selected for full-text screening. PubMed yielded 55 manuscripts, of which 23 were selected for full text screening. We deemed 8 retrospective series, 1 phase 2 prospective study, 3 randomized controlled trials, and 1 consensus contouring paper appropriate for inclusion. The data suggest that SRS/SRT to surgical cavities with prescription doses of 30 to 50 Gy equivalent effective dose (EQD) 2 <sub>10</sub> , 50 to 70 Gy EQD2 <sub>5</sub> , and 70 to 90 EQD2 <sub>2</sub> are associated with rates of local control ranging from 60.5% to 91% (median, 80.5%). Randomized data suggest improved local control with single-fraction SRS compared with observation and improved cognitive outcomes compared with whole-brain radiation therapy (WBRT). The toxicity of SRS/SRT in the postoperative setting was limited and is reviewed herein. Although randomized data raise concern for poorer local control after resection cavity SRS than WBRT, these findings may be driven by factors such as conservative prescription doses used in the SRS arm. Retrospective studies suggest high rates of local control after single-fraction SRS and hypofractionated SRT for postoperative brain metastases. With a superior neurocognitive profile and no survival disadvantage to withholding WBRT, the ISRS recommends SRS as first-line treatment for eligible postoperative patients. Emerging data suggest that fractionated SRT may provide superior local control compared with single-fraction SRS, in particular, for large tumor cavity volumes/diameters and potentially for patients with a preoperative diameter greater than 2.5 cm
    corecore