Effectiveness of Deep Brain Stimulation in Reducing Body Mass Index and Weight: A Systematic Review.

BACKGROUND: Obesity has become a major public health concern worldwide, with current behavioral, pharmacological, and surgical treatments offering varying rates of success and adverse effects. Neurosurgical approaches to treatment of refractory obesity include deep brain stimulation (DBS) on either specific hypothalamic or reward circuitry nuclei, which might contribute to weight reduction through different mechanisms. We aimed to determine the safety and clinical effect of DBS in medical refractory obesity. SUMMARY: Adhering to PRISMA guidelines, we performed a systematic review to identify all original studies - observational and experimental - in which DBS was performed to treat refractory obesity. From database inception to April 2021, we conducted our search in PubMed, Scopus, and LILACS databases using the following MeSH terms: "Obesity" OR "Prader-Willi Syndrome" AND "Deep Brain Stimulation." The main outcomes were safety and weight loss measured with the body mass index (BMI). The Grading of Recommendations Assessment, Development, and Evaluation methods were applied to evaluate the quality of evidence. This study protocol was registered with PROSPERO ID: CRD42019132929. Seven studies involving 12 patients met the inclusion criteria; the DBS target was the nucleus accumbens in four (57.1%), the lateral hypothalamic area in two (29.6%), and the ventral hypothalamus in one (14.3%). Further, 33% of participants had obesity secondary to Prader-Willi syndrome (PWS) and 66.6% had primary obesity. The global BMI average at baseline was 46.7 (SD: 9.6, range: 32.2-59.1), and after DBS, 42.8 (SD: 8.8, range: 25-53.9), with a mean difference of 3.9; however, the delta in PWS patients was -2.3 and 10 in those with primary obesity. The incidence of moderate side effects was 33% and included manic symptoms (N = 2), electrode fracture (N = 1), and seizure (N = 1); mild complications (41.6%) included skin infection (N = 2), difficulties falling asleep (N = 1), nausea (N = 1), and anxiety (N = 1). KEY MESSAGES: Despite available small case series and case reports reporting a benefit in the treatment of refractory obesity with DBS, this study emphasizes the need for prospective studies with longer follow-ups in order to further address the efficacy and indications.

Intraoperative clinical application of augmented reality in neurosurgery: A systematic review.

The interest and potential use of augmented reality (AR) in several medical fields since the early 90's has increased consistently. It provides intraoperative guidance for surgical procedures by rendering visible what cannot be seen directly, possibly affecting surgical outcomes. Our objective was to conduct a systematic review of the intraoperative clinical application of augmented reality in neurosurgery, in studies published during the last five years. We carried out an electronic search in the PUBMED database using the terms "Augmented Reality" and "Neurosurgery." After exclusions, 12 published articles that evaluated the utility of intraoperative clinical applications in surgical settings were included in our review. The results evaluated involved AR technique and visualization, time, complications, projection error, and located structures. We can conclude that the neurovascular application is the most frequent type of use for AR in neurosurgery (47.3%), followed by applications in neuro-oncological pathologies (46.7%), and non-vascular and non-neoplasic lesions (5.9%). The use of AR also allows a surgeon to maintain their view on the operative site permanently, and is useful for locating structures, guiding resections, and planning the craniotomy with more precision, decreasing the risk of injury. The intraoperative application of an augmented reality system helps to improve the quality and characteristics of the surgical field image. The injection of 3D images with AR allows for the successful integration of images in vascular, oncological and other lesions without the need of look away from the surgical field, improving safety, surgical experience, or clinical outcome. However, comparative studies are still required to determine its effectiveness.