Current strategies for optimizing deep brain stimulation (DBS) therapy involve multiple postoperative visits. During each visit, stimulation parameters are adjusted until desired therapeutic effects are achieved and adverse effects are minimized. However, the efficacy of these therapeutic parameters may decline with time due at least in part to disease progression, interactions between the host environment and the electrode, and lead migration. As such, development of closed-loop control systems that can respond to changing neurochemical environments, tailoring DBS therapy to individual patients, is paramount for improving the therapeutic efficacy of DBS. Evidence obtained using electrophysiology and imaging techniques in both animals and humans suggests that DBS works by modulating neural network activity. Recently, animal studies have shown that stimulation-evoked changes in neurotransmitter release that mirror normal physiology are associated with the therapeutic benefits of DBS. Therefore, to fully understand the neurophysiology of DBS and optimize its efficacy, it may be necessary to look beyond conventional electrophysiological analyses and characterize the neurochemical effects of therapeutic and non-therapeutic stimulation. By combining electrochemical monitoring and mathematical modeling techniques, we can potentially replace the trial-and-error process used in clinical programming with deterministic approaches that help attain optimal and stable neurochemical profiles. In this manuscript, we summarize the current understanding of electrophysiological and electrochemical processing for control of neuromodulation therapies. Additionally, we describe a proof-of-principle closed-loop controller that characterizes DBS-evoked dopamine changes to adjust stimulation parameters in a rodent model of DBS. The work described herein represents the initial steps toward achieving a “smart” neuroprosthetic system for treatment of neurologic and psychiatric disorders.

Background and Purpose-Moyamoya disease is an uncommon, cerebrovascular occlusive disease of unknown pathogenesis. Previously described Moyamoya cohorts include predominantly Asian populations or ethnically diverse North American cohorts. To gain further insight into the pathogenesis of moyamoya, we examined clinical characteristics of a primarily white, Midwestern US population Methods-Retrospective analysis of patients with angiographically confirmed moyamoya disease evaluated at our institution was performed. Prevalence of comorbidities, cerebrovascular risk factors, and autoimmune diseases were compared with the general population. Results-Ninety-four patients with moyamoya were evaluated; 72.3% were female. Ethnic composition was primarily white (85%

OBJectThe following study was conducted to identify risk factors for a postoperative CSF leak after vestibular schwannoma (VS) surgery. MethODs The authors reviewed a prospectively maintained database of all patients who had undergone resection of a VS at the Mayo Clinic between September 1999 and May 2013. Patients who developed a postoperative CSF leak within 30 days of surgery were compared with those who did not. Data collected included patient age, sex, body mass index (BMI), tumor size, tumor side, history of prior tumor treatment, operative time, surgical approach, and extent of resection. Both univariate and multivariate regression analyses were performed to evaluate all variables as risk factors of a postoperative CSF leak. results A total of 457 patients were included in the study, with 45 patients (9.8%) developing a postoperative CSF leak. A significant association existed between increasing BMI and a CSF leak, with those classified as overweight (BMI 25-29.9), obese (BMI 30-39.9), or morbidly obese (BMI ≥ 40) having a 2.5-, 3-, and 6-fold increased risk, respectively. Patients undergoing a translabyrinthine (TL) approach experienced a higher rate of CSF leaks (OR 2.5, 95% CI 1.3-4.6; p = 0.005), as did those who had longer operative times (OR 1.04, 95% CI 1.02-1.07; p = 0.0006). The BMI, a TL approach, and operative time remained independent risk factors on multivariate modeling. cONclusiONs Elevated BMI is a risk factor for the development of a postoperative CSF leak following VS surgery. Recognizing this preoperatively can allow surgeons to better counsel patients regarding the risks of surgery as well as perhaps to alter perioperative management in an attempt to decrease the likelihood of a leak. Patients undergoing a TL approach or having longer operative times are also at increased risk of developing a postoperative CSF leak.http://thejns.org/doi/abs/10.3171/2014.10.JNS14432 Key WOrDs cerebrospinal fluid leak; vestibular schwannoma; acoustic neuroma; predictors; risk factors; oncology aBBreviatiONs BMI = body mass index; ICP = intracranial pressure; MF = middle fossa; RS = retrosigmoid; TL = translabyrinthine; VS = vestibular schwannoma.

Therapeutic/care management, level III.