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OBJECTIVE Electrophysiologic mapping (EM) has been instrumental in advancing neuroscience and ensuring accurate lead placement for deep brain stimulation. However, EM is associated with increased operative time, expense, and potential risk. Intraoperative imaging to verify lead placement provides an opportunity to reassess the clinical role of EM. We investigated whether EM 1) provides new information that corrects suboptimal preoperative target selection by the physician or 2) simply corrects intraoperative stereotactic error, which can instead be quickly corrected with intraoperative imaging. METHODS Deep brain stimulation lead location errors were evaluated by measuring whether repositioning leads based on EM directed the final lead placement 1) away from or 2) toward the original target. We retrospectively identified 50 patients with 61 leads that required repositioning directed by EM. The stereotactic coordinates of each lead were determined with intraoperative computed tomography. RESULTS In 45 of 61 leads (74%), the electrophysiologically directed repositioning moved the lead toward the initial target. The mean radial errors between the preoperative plan and targeted contact coordinates before and after repositioning were 2.2 and 1.5 mm, respectively (P < 0.001). Microelectrode recording was more likely than test stimulation to direct leads toward the initial target (88% vs. 63%; P = 0.03). The nucleus targeted was associated with the likelihood of moving toward the initial target. CONCLUSIONS Electrophysiologic mapping corrected primarily for errors in lead placement rather than providing new information regarding errors in target selection. Thus, intraoperative imaging and improvements in stereotactic techniques may reduce or even eliminate dependence on EM.

OBJECTIVE Spinal cord stimulation (SCS) has been shown to be a safe and effective therapy for patients with chronic pain. However, some patients do not obtain or maintain adequate pain relief after SCS. The goal of this study was to identify factors that affect patient outcome with regard to SCS. MATERIALS AND METHODS A retrospective analysis of electronic medical records at a single site was performed. Records for 181 patients who received SCS implants from 2014 through 2016 were collected with follow-up data captured up to August 2019. Patient outcome was measured by device explantation and patient benefit from the SCS. Study parameters included demographic characteristics, history of pain, SCS implant characteristics, and postimplantation events. RESULTS An earlier diagnosis of radiculopathy was associated with an increased risk of poor benefit (relative risk [RR], 1.81; 95% CI, 1.19-2.74; p = 0.008). Postimplantation falls were associated with an increased risk of poor benefit (RR, 2.17; 95% CI, 1.48-3.17; p = 0.009). Device manufacturer was associated with both patient benefit and explantation. Device 2 was associated with a reduced risk of poor benefit (RR, 0.52; 95% CI, 0.32-0.85; p = 0.009). Device 4 was associated with an increased risk of poor benefit (RR, 1.71; 95% CI, 1.14-2.55; p = 0.02) and increased risk of device explantation (RR, 2.69; 95% CI, 1.2-6.02; p = 0.03). CONCLUSIONS Patient outcome was associated with diagnosis, postimplantation falls, and device manufacturer. Further investigation is recommended to confirm associations through prospective studies that can more accurately quantify patient outcome over longer periods.

Cancer-related pain is a uniquely challenging entity for treating practitioners for a variety of reasons, including its often severe and medically refractory nature, the emotional and social circumstances surrounding the disease process, and the frequently associated limited life expectancy.

OBJECTIVEVentral intermediate nucleus deep brain stimulation (DBS) for essential tremor is traditionally performed with intraoperative test stimulation and conscious sedation, without general anesthesia (GA). Recently, the authors reported retrospective data on 17 patients undergoing DBS after induction of GA with standardized anatomical coordinates on T1-weighted MRI sequences used for indirect targeting. Here, they compare prospectively collected data from essential tremor patients undergoing DBS both with GA and without GA (non-GA).METHODSClinical outcomes were prospectively collected at baseline and 3-month follow-up for patients undergoing DBS surgery performed by a single surgeon. Stereotactic, euclidean, and radial errors of lead placement were calculated. Functional (activities of daily living), quality of life (Quality of Life in Essential Tremor [QUEST] questionnaire), and tremor severity outcomes were compared between groups.RESULTSFifty-six patients underwent surgery: 16 without GA (24 electrodes) and 40 with GA (66 electrodes). The mean baseline functional scores and QUEST summary indices were not different between groups (p = 0.91 and p = 0.59, respectively). Non-GA and GA groups did not differ significantly regarding mean postoperative percentages of functional improvement (non-GA, 47.9% vs GA, 48.1%; p = 0.96) or QUEST summary indices (non-GA, 79.9% vs GA, 74.8%; p = 0.50). Accuracy was comparable between groups (mean radial error 0.9 ± 0.3 mm for non-GA and 0.9 ± 0.4 mm for GA patients) (p = 0.75). The mean euclidean error was also similar between groups (non-GA, 1.1 ± 0.6 mm vs GA, 1.2 ± 0.5 mm; p = 0.92). No patient had an intraoperative complication, and the number of postoperative complications was not different between groups (non-GA, n = 1 vs GA, n = 10; p = 0.16).CONCLUSIONSDBS performed with the patient under GA to treat essential tremor is as safe and effective as traditional DBS surgery with intraoperative test stimulation while the patient is under conscious sedation without GA.

OBJECTIVERecent studies have shown similar clinical outcomes between Parkinson disease (PD) patients treated with deep brain stimulation (DBS) under general anesthesia without microelectrode recording (MER), so-called “asleep” DBS, and historical cohorts undergoing “awake” DBS with MER guidance. However, few studies include internal controls. This study aims to compare clinical outcomes after globus pallidus internus (GPi) and subthalamic nucleus (STN) DBS using awake and asleep techniques at a single institution.METHODSPD patients undergoing awake or asleep bilateral GPi or STN DBS were prospectively monitored. The primary outcome measure was stimulation-induced change in motor function off medication 6 months postoperatively, measured using the Unified Parkinson’s Disease Rating Scale part III (UPDRS-III). Secondary outcomes included change in quality of life, measured by the 39-item Parkinson’s Disease Questionnaire (PDQ-39), change in levodopa equivalent daily dosage (LEDD), stereotactic accuracy, stimulation parameters, and adverse events.RESULTSSix-month outcome data were available for 133 patients treated over 45 months (78 GPi [16 awake, 62 asleep] and 55 STN [14 awake, 41 asleep]). UPDRS-III score improvement with stimulation did not differ between awake and asleep groups for GPi (awake, 20.8 points [38.5%]; asleep, 18.8 points [37.5%]; p = 0.45) or STN (awake, 21.6 points [40.3%]; asleep, 26.1 points [48.8%]; p = 0.20) targets. The percentage improvement in PDQ-39 and LEDD was similar for awake and asleep groups for both GPi (p = 0.80 and p = 0.54, respectively) and STN cohorts (p = 0.85 and p = 0.49, respectively).CONCLUSIONSIn PD patients, bilateral GPi and STN DBS using the asleep method resulted in motor, quality-of-life, and medication reduction outcomes that were comparable to those of the awake method.

5-Aminoleveulinic acid sonodynamic therapy (5-ALA SDT) is a drug-device strategy that exploits the metabolic liabilities of cancer. Following systemic administration of 5-ALA, aberrant tumor metabolism leads to accumulation of protoporphyrin-IX (PpIX). Activation of PpIX by non-invasive, non-ablative magnetic resonance-guided focused ultrasound (MRgFUS) induces reactive oxygen species and tumor cell death. This first-in-human Phase 0/1 study investigates the feasibility, safety, and biological effects of 5-ALA SDT in recurrent glioblastoma (GBM) patients. Six hours prior to SDT, adult patients with recurrent GBM are administered Sonala-001 (10mg/kg), an IV formulation of 5-ALA. In a Dose-Escalation Arm, 9-18 patients are assigned to one of three ascending acoustic energy doses of MRgFUS (200J/400J/800J, measured at transducer surface), followed by a four-day interval to planned tumor resection. In each patient, half the tumor volume, including Gadolinium-enhancing and nonenhancing tumor, is targeted with MRgFUS and the other half serves as an internal control. Using tumor pharmacodynamic endpoints, the Minimum Biological Dose (MBD) associated with 5-ALA SDT response is identified. In a subsequent Time-Escalation Arm, 12 patients are treated at the MBD and assigned to one of two time-intervals between SDT and resection. As of May 1, accrual to the 200J dose level (n=3) is complete without significant drug- or device-related adverse events. No cellular or radiographic changes to non-targeted tissue were detected. The median Cmax for 5-ALA and PpIX were 307 µM and 319 nM, respectively. The oxidative stress biomarkers 4-hydroxynonenal, glutathione, cysteine, and thiol were significantly elevated in treated tissue vs. control. Similarly, the apoptosis biomarker cleaved caspase-3 was increased in treated tumor vs. control (median, 48.6% vs. 29.6%, p=0.05). This first-in-human experience with a new therapeutic modality for recurrent glioblastoma patients demonstrates that 5-ALA SDT is safe at 200J. Sonodynamic therapy leads to targeted oxidative stress and tumor cell death in human glioblastoma tissue.

OBJECTIVEAs the number of deep brain stimulation (DBS) procedures performed under general anesthesia (“asleep” DBS) increases, it is more important to assess the rates of adverse events, inpatient lengths of stay (LOS), and 30-day readmission rates in patients undergoing these procedures compared with those in patients undergoing traditional “awake” DBS without general anesthesia.METHODSAll patients in an institutional database who had undergone awake or asleep DBS procedures performed by a single surgeon between August 2011 and August 2014 were reviewed. Adverse events, inpatient LOS, and 30-day readmissions were analyzed.RESULTSA total of 490 electrodes were placed in 284 patients, of whom 126 (44.4%) underwent awake surgery and 158 (55.6%) underwent asleep surgery. The most frequent overall complication for the cohort was postoperative mental status change (13 patients [4.6%]), followed by hemorrhage (4 patients [1.4%]), seizure (4 patients [1.4%]), and hardware-related infection (3 patients [1.1%]). Mean LOS for all 284 patients was 1.19 ± 1.29 days (awake: 1.06 ± 0.46 days; asleep: 1.30 ± 1.67 days; p = 0.08). Overall, the 30-day readmission rate was 1.4% (1 awake patient, 3 asleep patients). There were no significant differences in complications, LOS, and 30-day readmissions between awake and asleep groups.CONCLUSIONSBoth awake and asleep DBS can be performed safely with low complication rates. The authors found no significant differences between the 2 procedure groups in adverse events, inpatient LOS, and 30-day readmission rates.

Facial pain occurs in approximately 80% of patients with head and neck cancers. Pain in these settings may result directly from the tumor, or indirectly as a side effect of oncological treatment of the tumor. Optimizing treatment for cancer pain of the face, therefore, involves a variety of diagnostic and treatment considerations, with the development of a successful treatment algorithm dependent on accurate diagnosis of the anatomical location of the pain, its relationship to the facial pain pathway, the type of pain being treated and, finally, patient's prognosis and preference for treatment modality. Beyond direct treatments to reduce tumor burden, a wide variety of neuro-ablative and neuro-augmentative approaches are available that may be tailored to a patient's specific pain syndrome and individual clinical context, taking into account the patient's treatment goals, life expectancy, other cancer-related medical problems, and end-of-life issues.

OBJECT Deep brain stimulation (DBS) performed under general anesthesia (“asleep” DBS) has not been previously reported for essential tremor. This is in part due to the inability to visualize the target (the ventral intermediate nucleus [VIM]) on MRI. The authors evaluate the efficacy of this asleep technique in treating essential tremor by indirect VIM targeting. METHODS The authors retrospectively reviewed consecutive cases of initial DBS for essential tremor performed by a single surgeon. DBS was performed with patients awake (n = 40, intraoperative test stimulation without microelectrode recording) or asleep (n = 17, under general anesthesia). Targeting proceeded with standardized anatomical coordinates on preoperative MRI. Intraoperative CT was used for stereotactic registration and lead position confirmation. Functional outcomes were evaluated with pre- and postoperative Bain and Findley Tremor Activities of Daily Living scores. RESULTS A total of 29 leads were placed in asleep patients, and 60 were placed in awake patients. Bain and Findley Tremor Activities of Daily Living Questionnaire scores were not significantly different preoperatively for awake versus asleep cohorts (p = 0.2). The percentage of postoperative improvement was not significantly different between asleep (48.6%) and awake (45.5%) cohorts (p = 0.35). Euclidean error (mm) was higher for awake versus asleep patients (1.7 ± 0.8 vs 1.2 ± 0.4, p = 0.01), and radial error (mm) trended higherfor awake versus asleep patients (1.3 ± 0.8 vs 0.9 ± 0.5, p = 0.06). There were no perioperative complications. CONCLUSIONS In the authors’ initial experience, asleep VIM DBS for essential tremor without intraoperative test stimulation can be performed safely and effectively.

OBJECT Recent studies show that deep brain stimulation can be performed safely and accurately without microelectrode recording ortest stimulation but with the patient under general anesthesia. The procedure couples techniques for direct anatomical targeting on MRI with intraoperative imaging to verify stereotactic accuracy. However, few authors have examined the clinical outcomes of Parkinson’s disease (PD) patients after this procedure. The purpose of this study was to evaluate PD outcomes following “asleep” deep brain stimulation in the globus pallidus internus (GPi). METHODS The authors prospectively examined all consecutive patients with advanced PD who underwent bilateral GPi electrode placement while under general anesthesia. Intraoperative CT was used to assess lead placement accuracy. The primary outcome measure was the change in the off-medication Unified Parkinson’s Disease Rating Scale motor score 6 months after surgery. Secondary outcomes included effects on the 39-Item Parkinson’s Disease Questionnaire (PDQ-39) scores, on-medication motor scores, and levodopa equivalent daily dose. Lead locations, active contact sites, stimulation parameters, and adverse events were documented. RESULTS Thirty-five patients (24 males, 11 females) had a mean age of 61 years at lead implantation. The mean radial error off plan was 0.8 mm. Mean coordinates for the active contact were 21.4 mm lateral, 4.7 mm anterior, and 0.4 mm superior to the midcommissural point. The mean off-medication motor score improved from 48.4 at baseline to 28.9 (40.3% improvement) at 6 months (p < 0.001). The PDQ-39 scores improved (50.3 vs 42.0; p = 0.03), and the levodopa equivalent daily dose was reduced (1207 vs 1035 mg; p = 0.004). There were no significant adverse events. CONCLUSIONS Globus pallidus internus leads placed with the patient under general anesthesia by using direct anatomical targeting resulted in significantly improved outcomes as measured by the improvement in the off-medication motor score at 6 months after surgery.

The retrosigmoid approach for microvascular decompression of the trigeminal nerve (TN) is an established and highly effective technique for the treatment of trigeminal neuralgia due to vascular compression. It is common to place a pledget or other cushion material between the source of vascular compression, typically the superior cerebellar artery (SCA), and the TN after vessel mobilization and decompression. A previous study demonstrated the use of a tentorial sling on the SCA to maintain decompression of the TN, with encouraging results. 1 In this video, we demonstrate a novel technique using a Gore-Tex (W. L. Gore & Associates, Newark, Delaware) sling wrapped around the SCA and secured with a vascular clip on the petrous dura to maintain decompression of the TN ( Video 1 ). Informed consent was obtained from the patient. He tolerated the procedure well with excellent pain relief and was discharged on postoperative day 1.

OBJECTIVEDeep brain stimulation (DBS) is a well-established, evidence-based therapy with FDA approval for Parkinson’s disease and essential tremor. Despite the early successful use of DBS to target the sensory thalamus for intractable facial pain, subsequent studies pursuing various chronic pain syndromes reported variable efficacy, keeping DBS for pain as an investigational and “off-label” use. The authors report promising results for a contemporary series of patients with intractable facial pain who were treated with DBS.METHODSPain outcomes for 7 consecutive patients with unilateral, intractable facial pain undergoing DBS of the ventral posteromedial nucleus of the thalamus (VPM) and the periaqueductal gray (PAG) were retrospectively reviewed. Pain was assessed preoperatively and at multiple postoperative time points using the visual analog scale (VAS), the Short-Form McGill Pain Questionnaire-2 (SF-MPQ-2), and the Pain Disability Index (PDI).RESULTSVAS scores significantly decreased from a mean ± SD of 9.0 ± 1.3 preoperatively to 2.6 ± 1.5 at 1 year postoperatively (p = 0.001). PDI scores decreased from a mean total of 48.5 to 28.5 (p = 0.01). SF-MPQ-2 scores decreased from a mean of 4.6 to 2.4 (p = 0.03). Notably, several patients did not experience maximum improvement until 6–9 months postoperatively, correlating with repeated programming adjustments.CONCLUSIONSDBS of the VPM and PAG is a potential therapeutic option for patients suffering from severe, intractable facial pain refractory to other interventions. Improved efficacy may be observed over time with close follow-up and active DBS programming adjustments.

Recently, lasting remission of hyperglycemia was achieved in rodent models of type 2 diabetes (T2D) by a single intracerebroventricular (icv) injection of FGF-1. While the mechanism underlying this effect is unknown, the lack of association with changes of body fat mass or risk of hypoglycaemia raises the possibility that icv FGF-1 normalizes the defended level of glycemia, rather than simply lowering blood glucose levels. Recent work from our lab has identified gluco-regulatory neurocircuits in the mediobasal hypothalamus (MBH) as targets for this FGF-1 effect. To investigate the mechanism underlying FGF-1 action in this brain area, we used large-scale single cell RNA-sequencing to identify and characterize FGF-1-responsive cells in mouse MBH. Based on >70,000 single cell MBH transcriptomes from diabetic ob/ob mice harvested 5d after a single icv injection of either FGF-1 or vehicle, we identified >20 cell clusters and >900 cell type-specific differentially expressed genes (p Disclosure M.A. Bentsen: None. D. Rausch: None. J. Scarlett: None. K.M. Alonge: None. P.N. Timshel: None. Z. Mirzadeh: None. A. Secher: Employee; Self; Novo Nordisk A/S. Stock/Shareholder; Self; Novo Nordisk A/S. Employee; Spouse/Partner; Gubra. R. Jorgensen: Employee; Self; Novo Nordisk Inc.. T. Pers: None. M.W. Schwartz: Consultant; Self; Novo Nordisk A/S. Research Support; Self; Novo Nordisk A/S.

Background: Many surgeons utilize assistants to perform procedures in more than one operating room at a given time using a practice known as overlapping surgery. Debate has continued as to whether overlapping surgery improves the efficiency and access to care or risks patient safety and outcomes. Objective: To examine effects of overlapping surgery in deep brain stimulation (DBS) for movement disorders. Methods: In this retrospective analysis of overlapping and non-overlapping cases, we evaluated stereotactic accuracy, operative duration, length of hospital stay, and the presence of hemorrhage, wound-related complications, and hardware-related complications requiring revision in adults with movement disorders undergoing DBS. Results: Of 324 cases, 141 (43.5%) were overlapping and 183 (56.5%) non-overlapping. Stereotactic error, number of brain penetrations, and postoperative length of hospitalization did not differ significantly (p ≥ 0.08) between the overlapping and non-overlapping groups. Mean operative duration was significantly longer for overlapping (81/141 [57.4%], 189.5 ± 10.8 min) than for non-overlapping cases (79/183 [43.2%], 169.9 ± 7.6 min; p = 0.004). There were no differences in rates of wound-related complications or hemorrhages, but overlapping cases had a significantly higher rate of hardware-related complications requiring revision (7/141 [5.0%] vs. 0/183 [0%]; p = 0.002). Conclusions: Overlapping and non-overlapping cases had comparable DBS lead placement accuracy. Overlapping cases had a longer operative duration and had a higher rate of hardware-related complications requiring revision.

Background Deep brain stimulation (DBS) is well-established, evidence-based therapy for Parkinson disease, essential tremor, and primary dystonia. Clinical outcome studies have recently shown that "asleep" DBS lead placement, performed using intraoperative imaging with stereotactic accuracy as the surgical endpoint, has motor outcomes comparable to traditional "awake" DBS using microelectrode recording (MER), but with shorter case times and improved speech fluency. Objective To identify procedural variables in DBS surgery associated with improved surgical efficiency and stereotactic accuracy. Methods Retrospective review of 323 cases with 546 leads placed (August 2011-October 2014). In 52% (n = 168) of cases, patients were asleep under general anesthesia without MER. Multivariate regression identified independent predictors of reduced surgery time and improved stereotactic accuracy. Results MER was an independent contributor to increased procedure time (+44 min; P = .03). Stereotactic accuracy was better in asleep patients. Accuracy was improved with frame-based stereotaxy at head of bed 0° vs frameless stereotaxy at head of bed 30°. Improved accuracy was also associated with shorter procedures (r = 0.17; P = .049). Vector errors were evenly distributed around the planned target for the globus pallidus internus, but directionally skewed for the subthalamic (medial-posterior) and ventral intermediate nuclei (medial-anterior). Conclusion Distinct procedural variables in DBS surgery are associated with reduced case times and improved stereotactic accuracy.

Deep brain stimulation is typically performed with intraoperative microelectrode recording and test stimulation for target confirmation. Recent studies have shown accurate, clinically efficacious results after lead placement without microelectrode recording or test stimulation, using interventional magnetic resonance imaging (MRI) or intraoperative computed tomography (CT; iCT) for verification of accuracy. The latter relies on CT–MRI fusion. To validate CT–MRI fusion in this setting, we compared stereotactic coordinates determined intraoperatively using CT–MRI fusion with those obtained on postoperative MRI. Deep brain stimulation electrodes were implanted with patients under general anesthesia. Direct targeting was performed on preoperative MRI, which was merged with preimplantation iCT images for stereotactic registration and postimplantation iCT images for accuracy confirmation. Magnetic resonance imaging was obtained 6 weeks postoperatively for comparison. Postoperative MRI was obtained for 48 patients, with 94 leads placed over a 1-year period. Vector error of the targeted contact relative to the initial plan was 1.1 ± 0.7 mm on iCT and 1.6 ± 0.7 mm on postoperative MRI. Variance comparisons (F-tests) showed that the discrepancy between iCT- and postoperative MRI-determined errors was attributable to measurement error on postoperative MRI, as detected in inter-rater reliability testing. In multivariate analysis, improved lead placement accuracy was associated with frame-based stereotaxy with the head of the bed at 0° compared with frameless stereotaxy with the head of the bed at 30° (P = 0.037). Intraoperative CT can be used to determine lead placement accuracy in deep brain stimulation surgery. The discrepancy between coordinates determined intraoperatively by CT–MRI fusion and postoperatively by MRI can be accounted for by inherent measurement error. © 2014 International Parkinson and Movement Disorder Society

Object After complete resection and radiation therapy, the 10-year overall survival rates for adult patients with posterior fossa ependymomas approach 85%. This favorable outcome profile emphasizes the critical importance of functional preservation to this patient population. Here, the authors identify predictors of functional outcome following microsurgical resection of adult posterior fossa ependymomas. Methods The authors identified adult patients with newly diagnosed WHO Grade II posterior fossa ependymomas who underwent microsurgical resection at the Barrow Neurological Institute from 1990 to 2011. Clinical and radiographic variables were collected, including volumetric extent of resection, foramen of Luschka extension, cystic changes, peritumoral T2 signal changes, Karnofsky Performance Scale (KPS) score, National Institutes of Health Stroke Scale (NIHSS) score, progression-free survival (PFS), and overall survival (OS). Results Forty-five patients were identified, with a median clinical follow-up of 103 months. The median PFS and OS were 6.8 and 8.6 years, respectively. Extent of resection and adjuvant radiotherapy were predictive of improved PFS (p = 0.005) and were nonsignificantly associated with improved OS. Univariate analysis revealed that tumor size (p < 0.001), cystic changes (p < 0.01), postoperative T2 signal (p < 0.01), and CSF diversion (p = 0.048) predicted functional and neurological recovery rates, based on KPS and NIHSS scores, respectively. Multivariate regression analysis identified tumor size (p < 0.001), cystic changes (p = 0.01), and CSF diversion (p = 0.02) as independent predictors of slower functional recovery, while only tumor size (p = 0.007) was an independent predictor of neurological recovery. Specifically, by 6 weeks postoperatively, baseline KPS score was recovered by only 43.8% of patients with tumors larger than 30 cm3 (vs 72.4% patients with tumors < 30 cm3), 35.3% of patients with cystic tumors (vs 78.6% of patients with noncystic tumors), and 46.7% of patients requiring CSF diversion (vs 70% of patients not requiring CSF diversion). Conclusions Greater extent of resection and adjuvant radiotherapy significantly improve PFS in adult patients with posterior fossa ependymomas. Tumor size, cystic changes, and the need for CSF diversion were independent predictors of the rate of functional recovery in this patient population. Taken together, these functional outcome predictors may guide preoperative estimations of recovery following microsurgical resection.

Objective Although performing deep brain stimulation (DBS) with the patient under general anesthesia without microelectrode recording (MER) or intraoperative test stimulation (ITS) for movement disorders (“asleep” DBS) has become increasingly popular, its feasibility is based on the untested assumption that stereotactic accuracy correlates with positive clinical outcomes. To investigate outcomes after asleep DBS without MER or neurophysiological testing, we reviewed the medical literature on the topic. Methods We searched PubMed to identify all studies reporting clinical outcomes for patients who underwent DBS without MER or ITS for Parkinson disease (PD) or essential tremor (ET). Results We identified 9 studies with level 3b (n = 3) or level 4 evidence (n = 6). Eight PD studies (220 patients) reported asleep placement of 431 electrodes (341 subthalamic nucleus, 90 globus pallidus interna). Unified Parkinson Disease Rating Scale motor examination−III scores for 208 patients demonstrated significant improvement (40.2%−65%) at 6–12 months. The levodopa equivalent daily dose for 115 patients was significantly reduced (14%−49.3%) at 6–12 months in 103 patients. Two studies with a comparison cohort undergoing “awake” DBS with MER found no differences in postoperative Unified Parkinson Disease Rating Scale−III improvement or levodopa equivalent daily dose reduction. One study of asleep DBS for ET found no difference in functional outcomes between 17 patients undergoing asleep ventral intermediate nucleus DBS and 40 patients undergoing awake placement with ITS. Conclusions Initial evidence suggests that asleep DBS can be performed safely for PD and ET with good clinical outcomes. Long-term follow-up, larger cohorts, and double-armed studies are needed to validate these initial results.

Background: Deep brain stimulation (DBS) hardware infection is a serious complication, often resulting in multiple hardware salvage attempts, hospitalizations, and long-term antibiotic therapy. Objectives: We aimed to quantify the costs of DBS hardware-related infections in patients undergoing eventual device explantation. Methods: Of 362 patients who underwent 530 electrode placements (1 January 2010 to 30 December 2014), 16 (4.4%) had at least 2 hardware salvage procedures. Most (n = 15 [93.8%]) required complete explantation due to recurrent infection. Financial data (itemized hospital and physician costs) were available for 13 patients and these were analyzed along with the demographic data. Results: Each patient underwent 1-5 salvage procedures (mean 2.5 ± 1.4; median 2). The mean total cost for a patient undergoing the median number of revisions (n = 2), device explantation, and subsequent reimplantation after infection clearance was USD 75,505; just over half this cost (54.2% [USD 40,960]) was attributable to reimplantation, and nearly one-third (28.9% [USD 21,816]) was attributable to hardware salvage procedures. Operating-room costs were the highest cost category for hardware revision and explantation. Medical and surgical supplies accounted for the highest reimplantation cost. Conclusions: DBS infection incurs significant health care costs associated with hardware salvage attempts, explantation, and reimplantation. The highest cost categories are operating-room services and medical and surgical supplies.

The authors introduce the azygos anterior cerebral artery (ACA) bypass as an option for revascularizing distal ACA territories, as part of a strategy to trap giant anterior communicating artery (ACoA) aneurysms. In this procedure, the aneurysm is exposed with an orbitozygomatic-pterional craniotomy and distal ACA vessels are exposed with a bifrontal craniotomy. The uninvolved contralateral A2 segment of the ACA serves as a donor vessel for a short radial artery graft. The contralateral pericallosal artery (PcaA) and the callosomarginal artery (CmaA) are connected to the graft in the interhemispheric fissure using the double reimplantation technique. Three anastomoses create an azygos system supplying the entire ACA territory, enabling the surgeon to trap the aneurysm incompletely. Retrograde flow from the CmaA supplies the ipsilateral recurrent artery of Heubner, and the aneurysm lumen thromboses. The azygos bypass was successfully performed to treat a 47-year-old woman with a giant, thrombotic ACoA aneurysm supplied by the A1 segment of the left ACA, with left PcaA and CmaA originating from the aneurysm base. The authors conclude that the azygos ACA bypass is a novel option for revascularizing PcaA and CmaA, as part of the overall treatment of giant ACoA aneurysms.

Schwannomas of the craniocervical region are rare and formidable surgical lesions. Most patients become symptomatic with vague symptoms of headache or neck pain although some show evidence of lower cranial nerve dysfunction, including dysphagia or hoarseness. In addition to complete resection, the primary surgical goals in the modern era include preservation and restoration of function of the lower cranial nerves and of hearing and facial nerve function. Achieving these goals requires a nuanced understanding of several skull base approaches and their combinations, including the far-lateral approach and its extensions. With improvements in preoperative planning, advanced imaging, surgical techniques, and postoperative care, modern surgical series have demonstrated improved postoperative morbidity profiles, with special attention to postoperative swallowing function, and successful clinical outcomes in this patient population.

Objective Lateral supracerebellar-infratentorial approaches are established for lesions in ambient cistern and posterolateral midbrain, but published surgical experiences do not describe results with this approach in the sitting position. Gravity retraction of the cerebellum opens this surgical corridor and dramatically alters exposure, creating 2 variations of the lateral supracerebellar-infratentorial approach: the supracerebellar-supratrochlear approach and the infratentorial-infratrochlear approach. Methods We reviewed our experience treating cavernous malformations and arteriovenous malformations (AVMs) of the posteroinferior thalamus and posterolateral midbrain by use of supracerebellar-supratrochlear and infratentorial-infratrochlear approaches. Microsurgical technique, clinical data, radiographic features, and neurological outcomes were evaluated. Results During an 11-year surgical experience with 341 cavernous malformation patients and 402 AVM patients, 8 patients were identified, 6 with cavernous malformations and 2 with AVMs. Infratentorial-infratrochlear approaches were used in 4 patients (50%), including 3 with inferolateral midbrain cavernous malformations. Supracerebellar-supratrochlear approaches were used in 4 patients (50%), including 2 with posterior thalamic lesions surfacing on pulvinar. Resections were radiographically complete in all cases. There were no new, permanent neurological deficits, nor were there any medical or surgical complications. There has been no evidence of rebleeding or recurrence. Conclusions Gravity retraction of the cerebellum transforms the lateral supracerebellar-infratentorial approach, enhancing exposure and approach trajectories that can be achieved with patients in prone or lateral positions. The increased upward viewing angle of the supracerebellar-supratrochlear approach accesses the posteroinferior thalamus. The increased downward-viewing angle of the infratentorial-infratrochlear approach accesses cerebellomesencephalic fissure and posterolateral midbrain. These approaches open wide corridors for safe surgical resection of symptomatic cavernous malformations and AVMs.

Language sites in the cortex of the brain vary among patients. Language mapping while the patient is awake is an intraoperative technique designed to minimize language deficits associated with brain-tumor resection.To study language function after brain-tumor resection with language mapping, we examined 250 consecutive patients with gliomas. Positive language sites (i.e., language regions in the cortex of the brain, 1 cm by 1 cm, which were temporarily inactivated by means of a bipolar electrode) were identified and categorized into cortical language maps. The tumors were resected up to 1 cm from the cortical areas where intraoperative stimulation produced a disturbance in language. Our resection strategy did not require identification of the stimulation-induced language sites within the field of exposure.A total of 145 of the 250 patients (58.0%) had at least one site with an intraoperative stimulation-induced speech arrest, 82 patients had anomia, and 23 patients had alexia. Overall, 3094 of 3281 cortical sites (94.3%) were not associated with stimulation-induced language deficits. A total of 159 patients (63.6%) had intact speech preoperatively. One week after surgery, baseline language function remained in 194 patients (77.6%), it worsened in 21 patients (8.4%), and 35 patients (14.0%) had new speech deficits. However, 6 months after surgery, only 4 of 243 surviving patients (1.6%) had a persistent language deficit. Cortical maps generated with intraoperative language data also showed surprising variability in language localization within the dominant hemisphere.Craniotomies tailored to limit cortical exposure, even without localization of positive language sites, permit most gliomas to be aggressively resected without language deficits. The composite language maps generated in our study suggest that our current models of human language organization insufficiently account for observed language function.

Introduction Adult spinal deformity (ASD) surgery carries the risk of spinal cord injury. Spinal cord ischemia is often implicated in the pathogenesis but has not been directly investigated. Here we present our index case as a proof of concept for a study evaluating the role of spinal cord perfusion (SCP) changes in ASD correction. Methods ASD surgery was performed in the usual fashion with the addition of 1) SCP monitoring, using laser Doppler probe fixated to the dura at the level of the pedicle subtraction osteotomy (PSO) and 2) intrathecal pressure monitoring, using a lumbar drain. Somatosensory evoked potential (SSEP) and motor evoked potential (MEP) were monitored throughout the case. Results An 84-year-old male with kyphoscoliosis and progressive myelopathy causing diminished motor and sensory function was treated with T4 PSO and long segment reconstruction. At baseline, SSEP signals were detectable in all 4 extremities, MEP signals were present in the right foot only, intrathecal pressure was 4 mm Hg, and mean SCP was 21.2 perfusion units. The osteotomy was performed and reduced in 2 steps. After the first step of reduction, MEP signals appeared in the left leg and increased in amplitude in the right leg, and SCP simultaneously increased to 205.6. Further reduction led to MEP signal loss in both legs and decrease in SCP to 39.2. With partial reversal of the reduction, MEP signals returned in both legs and SCP improved to 76.0. Final reduction maneuvers were then performed in a delayed fashion before closure, with stable MEP signals and a final SCP of 42.9. SSEP signals, vital signs, and intrathecal pressure were stable throughout the case. Postoperatively the patient was neurologically stable. Conclusions The present case provides the first direct evidence that fluctuations in SCP may contribute to neurologic changes during ASD surgery. Further investigation is under way to further elucidate the underlying mechanisms, with the ultimate goal of developing targeted strategies for spinal cord protection during these high-risk cases.