Outcomes using linear accelerator stereotactic radiosurgery for the treatment of trigeminal neuralgia: A single-center, retrospective study.

Background: Linear accelerator (LINAC)-based stereotactic radiosurgery (SRS) treatment of trigeminal neuralgia (TN) may have similar efficacy to Gamma Knife SRS (GK-SRS), but the preponderance of data comes from patients treated with GK-SRS. Our objective was to analyze the outcomes for LINAC-based treatment of TN in patients at our institution. Methods: We retrospectively analyzed data for patients who underwent LINAC-based SRS for TN from 2006 to 2018. Data were collected from the patients' medical records. Nonparametric statistics were used for the analysis. Results: Of the 41 patients treated with LINAC-based SRS (typically 90 Gy dosed using a 4 mm collimator for one fraction) during that time, follow-up data of >3 weeks post-SRS were available for 32 patients. The median pretreatment Barrow Neurological Institute (BNI) pain score was 5 (range 4-5). The follow-up period ranged from 0.9 to 113.2 months (median 5 months). There was significant improvement in postradiation BNI pain score (P < 0.001), with 23 (72%) patients who improved to a BNI pain score of 1-3. One patient had bothersome hypoesthesia postradiation. Approximately 38% of patients who had initial pain control had recurrence of symptoms (BNI > 3). Survival analysis showed a median time to pain recurrence of 30 months. There was no relationship between prior microvascular decompression (MVD) surgery and change in BNI pain score pre- to posttreatment. Conclusion: The results demonstrate that LINAC-based SRS is an effective means to treat TN. Prior MVD surgery did not affect efficacy of SRS in lowering the BNI score from pre- to posttreatment in this patient cohort.

Asleep Deep Brain Stimulator Placement in the Intraoperative Magnetic Resonance Imaging System Hybrid Operating Suite: 2-Dimensional Operative Video.

Asleep, image-guided deep brain stimulation (DBS) placement is rapidly gaining popularity because it offers greater patient comfort and comparable accuracy with frame-based methods using microelectrode recording.1 In this video, we demonstrate our protocol to use the frameless, stereotactic ClearPoint system (MRI Interventions Inc, Irvine, California) to place DBS electrodes within an intraoperative magnetic resonance imaging hybrid operating suite (IMRIS; Deerfield Imaging Inc, Minnetonka, Minnesota).1-4 This system uses a skull-mounted aiming device coupled with sequential, intraoperative magnetic resonance imaging guidance to direct DBS lead placement to subcortical targets.2,5 Importantly, this method allows the patient to remain asleep during the operation and does not require medication holidays or additional microelectrode recording equipment. The literature indicates it has comparable accuracy1,6 and outcomes2 with the awake method. We demonstrate this technique with the case of a patient with Parkinson disease who required lead placement in the bilateral subthalamic nuclei.7-9 The patient consented to the procedure and publication. Patient positioning, draping nuances, initial indirect targeting, and final direct targeting are demonstrated. Risks of the operation include a risk of hemorrhage, hardware failure, and infection.10 DBS is currently an underutilized treatment option for patients with Parkinson disease.11 Offering the asleep option may be more tolerable for many patients who are wary of awake surgery.

Evaluation of a D-Dimer Protocol for Detection of Venous Thromboembolism.

BACKGROUND: The use of venous duplex ultrasonography (VDU) for confirmation of deep venous thrombosis in neurosurgical patients is costly and requires experienced personnel. We evaluated a protocol using D-dimer levels to screen for venous thromboembolism (VTE), defined as deep venous thrombosis and asymptomatic pulmonary embolism. METHODS: We used a retrospective bioinformatics analysis to identify neurosurgical inpatients who had undergone a protocol assessing the serum D-dimer levels and had undergone a VDU study to evaluate for the presence of VTE from March 2008 through July 2017. The clinical risk factors and D-dimer levels were evaluated for the prediction of VTE. RESULTS: In the 1918 patient encounters identified, the overall VTE detection rate was 28.7%. Using a receiver operating characteristic curve, an area under the curve of 0.58 was identified for all D-dimer values (P = 0.0001). A D-dimer level of ≥2.5 µg/mL on admission conferred a 30% greater relative risk of VTE (sensitivity, 0.43; specificity, 0.67; positive predictive value, 0.27; negative predictive value, 0.8). A D-dimer value of ≥3.5 µg/mL during hospitalization yielded a 28% greater relative risk of VTE (sensitivity, 0.73; specificity, 0.32; positive predictive value, 0.24; negative predictive value, 0.81). Multivariable logistic regression showed that age, male sex, length of stay, tumor or other neurological disease diagnosis, and D-dimer level ≥3.5 µg/mL during hospitalization were independent predictors of VTE. CONCLUSIONS: The D-dimer protocol was beneficial in identifying VTE in a heterogeneous group of neurosurgical patients by prompting VDU evaluation for patients with a D-dimer values of ≥3.5 µg/mL during hospitalization. Refinement of this screening model is necessary to improve the identification of VTE in a practical and cost-effective manner.

Emergent Reversal of Direct Oral Anticoagulants Permitting Neurosurgical Intervention for Nonhemorrhagic Pathology.

BACKGROUND: Direct oral anticoagulants (DOACs) are becoming the medication of choice for the management of venous thromboembolism and stroke prevention in atrial fibrillation because of simplified dosing, a more predictive pharmacokinetic profile, and better clinical outcomes when compared with traditional vitamin K antagonists. Recently, reversal agents for DOACs have been approved by the U.S. Food and Drug Administration for use in managing life-threatening or uncontrolled bleeding; however, for acute nonhemorrhagic conditions requiring surgical intervention, such as acute hydrocephalus requiring ventriculostomy, there is little evidence to help guide appropriate management for patients on DOACs. CASE DESCRIPTION: We report the use of andexanet alfa to counteract rivaroxaban treatment in a 28-year-old woman who developed herniation syndrome and acute hydrocephalus from a cerebellar tumor. CONCLUSIONS: We describe how appropriate timing of administration of the DOAC reversal agent may permit urgent neurosurgical intervention.

The effect of supplementation of vitamin D in neurocritical care patients: RandomizEd Clinical TrIal oF hYpovitaminosis D (RECTIFY).

OBJECTIVE: Hypovitaminosis D is prevalent in neurocritical care patients, but the potential to improve patient outcome by replenishing vitamin D has not been investigated. This single-center, double-blinded, placebo-controlled, randomized (1:1) clinical trial was designed to assess the effect on patient outcome of vitamin D supplementation in neurocritical care patients with hypovitaminosis D. METHODS: From October 2016 until April 2018, emergently admitted neurocritical care patients with vitamin D deficiency (≤ 20 ng/ml) were randomized to receive vitamin D3 (cholecalciferol, 540,000 IU) (n = 134) or placebo (n = 133). Hospital length of stay (LOS) was the primary outcome; secondary outcomes included intensive care unit (ICU) LOS, repeat vitamin D levels, patient complications, and patient disposition. Exploratory analysis evaluated specific subgroups of patients by LOS, Glasgow Coma Scale (GCS) score, and Simplified Acute Physiology Score (SAPS II). RESULTS: Two-hundred seventy-four patients were randomized (intent-to-treat) and 267 were administered treatment within 48 hours of admission (as-treated; 61.2% of planned recruitment) and monitored. The mean age of as-treated patients was 54.0 ± 17.2 years (56.9% male, 77.2% white). After interim analysis suggested a low conditional power for outcome difference (predictive power 0.12), the trial was halted. For as-treated patients, no significant difference in hospital LOS (10.4 ± 14.5 days vs 9.1 ± 7.9 days, p = 0.4; mean difference 1.3, 95% CI -1.5 to 4.1) or ICU LOS (5.8 ± 7.5 days vs 5.4 ± 6.4 days, p = 0.4; mean difference 0.4, 95% CI -1.3 to 2.1) was seen between vitamin D3 and placebo groups, respectively. Vitamin D3 supplementation significantly improved repeat serum levels compared with placebo (20.8 ± 9.3 ng/ml vs 12.8 ± 4.8 ng/ml, p < 0.001) without adverse side effects. No subgroups were identified by exclusion of LOS outliers or segregation by GCS score, SAPS II, or severe vitamin D deficiency (≤ 10 ng/ml). CONCLUSIONS: Despite studies showing that vitamin D can predict prognosis, supplementation in vitamin D-deficient neurocritical care patients did not result in appreciable improvement in outcomes and likely does not play a role in acute clinical recovery.Clinical trial registration no.: NCT02881957 (clinicaltrials.gov).

A retrospective evaluation of automated optimization of deep brain stimulation parameters.

OBJECTIVE: We performed a retrospective analysis of an optimization algorithm for the computation of patient-specific multipolar stimulation configurations employing multiple independent current/voltage sources. We evaluated whether the obtained stimulation configurations align with clinical data and whether the optimized stimulation configurations have the potential to lead to an equal or better stimulation of the target region as manual programming, while reducing the time required for programming sessions. APPROACH: For three patients (five electrodes) diagnosed with essential tremor, we derived optimized multipolar stimulation configurations using an approach that is suitable for the application in clinical practice. To evaluate the automatically derived stimulation settings, we compared them to the results of the monopolar review. MAIN RESULTS: We observe a good agreement between the findings of the monopolar review and the optimized stimulation configurations, with the algorithm assigning the maximal voltage in the optimized multipolar pattern to the contact that was found to lead to the best therapeutic effect in the clinical monopolar review in all cases. Additionally, our simulation results predict that the optimized stimulation settings lead to the activation of an equal or larger volume fraction of the target compared to the manually determined settings in all cases. SIGNIFICANCE: Our results demonstrate the feasibility of an automatic determination of optimal DBS configurations and motivate a further evaluation of the applied optimization algorithm.

Spine trauma and spinal cord injury in Utah: a geographic cohort study utilizing the National Inpatient Sample.

OBJECTIVE: The objective of this study was to investigate the effect of hospital type and patient transfer during the treatment of patients with vertebral fracture and/or spinal cord injury (SCI). METHODS: The National Inpatient Sample (NIS) database was queried to identify patients treated in Utah from 2001 to 2011 for vertebral column fracture and/or SCI (ICD-9-CM codes 805, 806, and 952). Variables related to patient transfer into and out of the index hospital were evaluated in relation to patient disposition, hospital length of stay, mortality, and cost. RESULTS: A total of 53,644 patients were seen (mean [± SEM] age 55.3 ± 0.1 years, 46.0% females, 90.2% white), of which 10,620 patients were transferred from another institution rather than directly admitted. Directly admitted (vs transferred) patients showed a greater likelihood of routine disposition (54.4% vs 26.0%) and a lower likelihood of skilled nursing facility disposition (28.2% vs 49.2%) (p < 0.0001). Directly admitted patients also had a significantly shorter length of stay (5.6 ± 6.7 vs 7.8 ± 9.5 days, p < 0.0001) and lower total charges ($26,882 ± $37,348 vs $42,965 ± $52,118, p < 0.0001). A multivariable analysis showed that major operative procedures (hazard ratio [HR] 1.7, 95% confidence interval [CI] 1.4-2.0, p < 0.0001) and SCI (HR 2.1, 95% CI 1.6-2.8, p < 0.0001) were associated with reduced survival whereas patient transfer was associated with better survival rates (HR 0.4, 95% CI 0.3-0.5, p < 0.0001). A multivariable analysis of cost showed that disposition (ß = 0.1), length of stay (ß = 0.6), and major operative procedure (ß = 0.3) (p < 0.0001) affected cost the most. CONCLUSIONS: Overall, transferred patients had lower mortality but greater likelihood for poor outcomes, longer length of stay, and higher cost compared with directly admitted patients. These results suggest some significant benefits to transferring patients with acute injury to facilities capable of providing appropriate treatment, but also support the need to further improve coordinated care of transferred patients, including surgical treatment and rehabilitation.

Trends and Cost Analysis of Upper Extremity Nerve Injury Using the National (Nationwide) Inpatient Sample.

OBJECTIVE: Epidemiology in upper extremity peripheral nerve injury (PNI) has not been comprehensively evaluated. The aim of this study was to calculate updated incidence of upper extremity PNIs in the United States and examine clinical trends and costs using a national database. METHODS: The National (Nationwide) Inpatient Sample was used to evaluate patients with upper extremity PNI (International Classification of Diseases, Ninth Revision, Clinical Modification 9534, 9550-9559) in 2001-2013. RESULTS: A weighted total of 170,579 patients experienced upper extremity PNI, representing a mean incidence of 43.8/1 million people annually. Mean (± SEM) age of patients was 38.1 ± 0.05 years, 74.3% of patients were male, and 49.0% were Caucasian. PNIs occurred to the ulnar (17.8%), radial (15.1%), digital (18.0%), median (13.0%), multiple (11.5%), and other (10.1%) nerves and brachial plexus (14.5%). The number of upper extremity PNIs decreased overall. Average care charge was $47,004 ± $185, with an average increase of $4623/year and compound annual growth rate of 9.59%. Although surgical nerve repair and home disposition were common with isolated PNIs, patients with brachial plexus PNIs did not have nerve surgery and were more likely to be discharged to skilled nursing facilities. Multivariate analysis showed that length of stay (ß = 0.677, P = 0.0001) and number of procedures (ß = 0.188, P = 0.0001) most affected total patient charges. CONCLUSIONS: These results suggest an overall decrease in number of PNIs, suggesting lower incidence or frequency of detection; however, the cost of care has increased. Despite advances in nerve repair techniques, nerve surgery rates have not increased, especially for brachial plexus injuries, which may be undertreated.

Analysis of an overlapping surgery policy change on costs in a high-volume neurosurgical department.

OBJECTIVE: Overlapping surgery remains a controversial topic in the medical community. Although numerous studies have examined the safety profile of overlapping operations, there are few data on its financial impact. The authors assessed direct hospital costs associated with neurosurgical operations during periods before and after a more stringent overlapping surgery policy was implemented. METHODS: The authors retrospectively reviewed the records of nonemergency neurosurgical operations that took place during the periods from June 1, 2014, to October 31, 2014 (pre-policy change), and from June 1, 2016, to October 31, 2016 (post-policy change), by any of the 4 senior neurosurgeons authorized to perform overlapping cases during both periods. Cost data as well as demographic, surgical, and hospitalization-related variables were obtained from an institutional tool, the Value-Driven Outcomes database. RESULTS: A total of 625 hospitalizations met inclusion criteria for cost analysis; of these, 362 occurred prior to the policy change and 263 occurred after the change. All costs were reported as a proportion of the average total hospitalization cost for the entire cohort. There was no significant difference in mean total hospital costs between the prechange and postchange period (0.994 ± 1.237 vs 1.009 ± 0.994, p = 0.873). On multivariate linear regression analysis, neither the policy change (p = 0.582) nor the use of overlapping surgery (p = 0.273) was significantly associated with higher total hospital costs. CONCLUSIONS: A more restrictive overlapping surgery policy was not associated with a reduction in the direct costs of hospitalization for neurosurgical procedures.

Deep brain stimulation for the treatment of disorders of consciousness and cognition in traumatic brain injury patients: a review.

Traumatic brain injury (TBI) is a looming epidemic, growing most rapidly in the elderly population. Some of the most devastating sequelae of TBI are related to depressed levels of consciousness (e.g., coma, minimally conscious state) or deficits in executive function. To date, pharmacological and rehabilitative therapies to treat these sequelae are limited. Deep brain stimulation (DBS) has been used to treat a number of pathologies, including Parkinson disease, essential tremor, and epilepsy. Animal and clinical research shows that targets addressing depressed levels of consciousness include components of the ascending reticular activating system and areas of the thalamus. Targets for improving executive function are more varied and include areas that modulate attention and memory, such as the frontal and prefrontal cortex, fornix, nucleus accumbens, internal capsule, thalamus, and some brainstem nuclei. The authors review the literature addressing the use of DBS to treat higher-order cognitive dysfunction and disorders of consciousness in TBI patients, while also offering suggestions on directions for future research.

Outcomes in adults with cerebral venous sinus thrombosis: A retrospective cohort study.

Most patients with cerebral venous sinus thrombosis (CVST) treated with anticoagulation have good outcomes. We examined which factors were associated with poor outcomes after treatment. We retrospectively reviewed patients ≥18 years old who were diagnosed with CVST between 1997 and 2015. Good (modified Rankin score [mRS] ≤2) and poor outcomes were dichotomized. Demographic, historical, clinical, imaging, and treatment characteristics were compared. Eighty-nine patients received treatment for CVST (52.8% males, 74.2% Caucasian). Sixty-eight (76.4%) had good outcomes and 21 (23.6%) had poor outcomes. Poor outcome was associated with systemic or central nervous system (CNS) infection (p = 0.002), lower use of heparin-only therapy than interventional-only treatments (p = 0.003), and increased use of craniectomy (p = 0.002). Good outcomes were associated with migrainous headache on presentation (p = 0.01) and involvement of superficial cortical vessels only (p = 0.02). No prothrombotic or imaging findings correlated with poor outcome. Multivariable analysis showed that any clinical risk factor (p = 0.02) and headache (p = 0.02) predicted improved outcome whereas systemic or CNS infection (p = 0.02) and craniectomy (p = 0.02) predicted poor outcome. A published risk score showed a moderate ability to predict good outcome but not poor outcome. Overall sensitivity (23.8%), specificity (75.0%), and positive (24.0%) and negative (77.0%) predictive value suggested moderate prediction of good outcome and limited prediction of poor outcome. Rates of poor outcomes in CVST were comparable with previous investigations (23.6%), but prediction of poor outcome remains challenging in patients with CVST. Our results suggested that systemic infection and craniectomy were the most robust predictors of poor outcome.

Increased nationwide use of stereoencephalography for intracranial epilepsy electroencephalography recordings.

Intracranial electroencephalography (iEEG) can be performed using minimally invasive stereo-electroencephalography (SEEG) or by implanting subdural electrodes via a craniotomy or multiple burr holes. There is anecdotal evidence that SEEG is becoming more common in the United States, though this has yet to be quantified. To address this question, all SEEG and burr hole/craniotomy subdural iEEG procedures were extracted from the Centers for Medicare and Medicaid Services Part B data files for the years 2000-2016. National trends were compared over time. In 2016, SEEG became the most frequently performed intracranial monitoring procedure in the Medicare population, increasing from 28.8% of total cases in 2000 to 43.1% in 2016 (p = 0.02). The proportion of strip electrode cases (through burr holes) significantly declined, while the frequency of craniotomies for subdural grid placement did not significantly change. These data are consistent with a nationwide increase in the utilization of SEEG with a concomitant decline in burr hole placement of subdural strip electrodes in the United States. The factors driving these changes are unknown, but are likely due in part to the desire for minimally invasive surgical options.

Vitamin D status and 3-month Glasgow Outcome Scale scores in patients in neurocritical care: prospective analysis of 497 patients.

OBJECTIVE Vitamin D deficiency has been associated with a variety of negative outcomes in critically ill patients, but little focused study on the effects of hypovitaminosis D has been performed in the neurocritical care population. In this study, the authors examined the effect of vitamin D deficiency on 3-month outcomes after discharge from a neurocritical care unit (NCCU). METHODS The authors prospectively analyzed 25-hydroxy vitamin D levels in patients admitted to the NCCU of a quaternary care center over a 6-month period. Glasgow Outcome Scale (GOS) scores were used to evaluate their 3-month outcome, and univariate and multivariate logistic regression was used to evaluate the effects of vitamin D deficiency. RESULTS Four hundred ninety-seven patients met the inclusion criteria. In the binomial logistic regression model, patients without vitamin D deficiency (> 20 ng/dl) were significantly more likely to have a 3-month GOS score of 4 or 5 than those who were vitamin D deficient (OR 1.768 [95% CI 1.095-2.852]). Patients with a higher Simplified Acute Physiology Score (SAPS II) (OR 0.925 [95% CI 0.910-0.940]) and those admitted for stroke (OR 0.409 [95% CI 0.209-0.803]) or those with an "other" diagnosis (OR 0.409 [95% CI 0.217-0.772]) were significantly more likely to have a 3-month GOS score of 3 or less. CONCLUSIONS Vitamin D deficiency is associated with worse 3-month postdischarge GOS scores in patients admitted to an NCCU. Additional study is needed to determine the role of vitamin D supplementation in the NCCU population.

Impact of a more restrictive overlapping surgery policy: an analysis of pre- and postimplementation complication rates, resident involvement, and surgical wait times at a high-volume neurosurgical department.

OBJECTIVE Recently, overlapping surgery has been a source of controversy both in the popular press and within the academic medical community. There have been no studies examining the possible effects of more stringent overlapping surgery restrictions. At the authors' institution, a new policy was implemented that restricts attending surgeons from starting a second case until all critical portions of the first case that could require the attending surgeon's involvement are completed. The authors examined the impact of this policy on complication rates, neurosurgical resident education, and wait times for neurosurgical procedures. METHODS The authors performed a retrospective chart review of nonemergency neurosurgical procedures performed over two periods-from June 1, 2014, to October 31, 2014 (pre-policy change) and from June 1, 2016, to October 31, 2016 (post-policy change)-by any of 4 senior neurosurgeons at a single institution who were authorized to schedule overlapping cases. Information on preoperative evaluation, patient demographics, premorbid conditions, surgical variables, and postoperative course were collected and analyzed. RESULTS Six hundred fifty-three patients met inclusion criteria for complications analysis. Of these, 378 (57.9%) underwent surgery before the policy change. On multivariable regression analysis, neither overlapping surgery (odds ratio [OR] 1.072, 95% confidence interval [CI] 0.710-1.620) nor the overlapping surgery policy change (OR 1.057, 95% CI 0.700-1.596) was associated with overall complication rates. Similarly, neither overlapping surgery (OR 1.472, 95% CI 0.883-2.454) nor the overlapping surgery policy change (OR 1.251, 95% CI 0.748-2.091) was associated with numbers of serious complications. After the policy change, the percentage of procedures in which the senior assistant was a postresidency fellow increased significantly, from 11.9% to 34.2% (p < 0.001). In a multiple linear regression analysis of surgery wait times, patients undergoing surgery after the policy change had significantly longer delays from the decision to operate until the actual neurosurgical procedure (p < 0.001). CONCLUSIONS At the authors' institution, further restriction of overlapping surgery was not associated with a reduction in overall or serious complications. Resident involvement in neurosurgical procedures decreased significantly after the policy change, and this study suggests that wait times for neurosurgical procedures also significantly lengthened.

Emerging Technologies in Flow Diverters and Stents for Cerebrovascular Diseases.

PURPOSE OF REVIEW: Stents and flow diverters have revolutionized the treatment of cerebrovascular disease. Guglielmi coils, flexible microcatheters, and first-generation intracranial stents, such as Neuroform (Stryker Neurovascular) and Enterprise stents (Codman/DePuy-Synthes), have paved the way for the development of the Pipeline Embolization Device (PED) (ev3/Covidien/Medtronic) and other endovascular approaches. RECENT FINDINGS: This review discusses the historical development of flow diverter technologies from the PED to similar devices, such as the Surpass stent (Stryker Neurovascular), the Flow-Redirection Endoluminal Device (FRED; MicroVention, Inc.), the SILK stent (Balt Extrusion), and the p64 Flow Modulation Device (Phenox). In addition, the potential use of drug-eluting stents and various bioresorbable scaffolds (e.g., poly-L-lactic acid, magnesium), new developments in stent material (e.g., thin-film nitinol), design (e.g., biocompatible polymers, embedded microcircuitry, flow models), and potential applications for flow diverters will be considered. Endovascular treatment of cerebrovascular disease is rapidly advancing via continued development of new technology.