Safety of vagus nerve stimulation and responsive neurostimulation used in combination for multifocal and generalized onset epilepsy in pediatric patients

OBJECTIVE

The aim of this study was to assess the safety and efficacy of combined active responsive neurostimulation (RNS) and vagus nerve stimulation (VNS) therapies in pediatric patients with drug-resistant epilepsy.

METHODS

A single-center retrospective chart review was conducted on pediatric patients implanted with the RNS System with a concomitant active VNS System (VNS+RNS) between 2015 and 2021. Patients with at least 1 month of overlapping concomitant VNS and RNS treatment were included. Patients who had an RNS device implanted after 21 years of age, those who had responsive neurostimulators implanted after their VNS was inactivated, or those in whom the VNS battery died and was not replaced before RNS System implantation were excluded.

RESULTS

Seven pediatric VNS+RNS patients were identified, and their courses of treatment were evaluated. All patients tolerated concurrent VNS and RNS treatment well, no device-device interactions were identified, and no major treatment-related adverse effects were noted. The median follow-up after RNS System implantation was 1.2 years. By electroclinical criteria, all 7 patients achieved 75%-99% reductions in the frequency of disabling seizures after RNS System implantation. By patient and caregiver report, 2 patients (28.6%) had 75%-99% reductions in the frequency of their disabling seizures, 2 patients (28.6%) achieved 50%-74% reductions, 2 patients achieved 1%-24% reduction in frequency of disabling seizures, and 1 patient (14.3%) experienced a 1%-24% increase in seizure frequency. The available VNS magnet swipe data identified 2 patients with 75%-99% reductions in seizure frequency as measured by magnet swipes, one with 25%-49% reductions and the other with 1%-24% increases in seizure frequency as measured by magnet swipes.

CONCLUSIONS

This study demonstrated that RNS and VNS therapies can safely be used simultaneously in pediatric patients. RNS may potentially augment the therapeutic effects of VNS treatment. Patients in whom a response to VNS has been suboptimal should still be considered for RNS therapy.

Effect of tracheostomy timing in pediatric patients with traumatic brain injury

BACKGROUND

Traumatic brain injury (TBI) is a prevalent cause of disability and death in the pediatric population, often requiring prolonged mechanical ventilation. Patients with significant TBI or intracranial hemorrhage require advanced airway management to protect against aspiration, hypoxia, and hypercarbia, eventually necessitating tracheostomy. While tracheostomy is much less common in children compared to adults, its prevalence among pediatric populations has been steadily increasing. Although early tracheostomy has demonstrated improved outcomes in adult patients, optimal tracheostomy timing in the pediatric population with TBI remains to be definitively established.

OBJECTIVE

This retrospective cohort analysis aims to evaluate pediatric TBI patients who undergo tracheostomy and to investigate the impact of tracheostomy timing on outcomes.

DESIGN/METHODS

The Healthcare Cost and Utilization Project (HCUP) Kids' Inpatient Database (KID), collected between in 2016 and 2019, was queried using International Classification of Disease 10th edition (ICD10) codes for patients with traumatic brain injury who had received a tracheostomy. Baseline demographics, insurance status, and procedural day data were analyzed with univariate and multivariate regression analyses. Propensity score matching was performed to estimate the incidence of medical complications and mortality related to early versus late tracheostomy timing (as defined by median = 9 days).

RESULTS

Of the 68,793 patients (mean age = 14, IQR 4-18) who suffered a TBI, 1,956 (2.8%) received a tracheostomy during their hospital stay. TBI patients who were tracheostomized were older (mean age = 16.5 vs 11.4 years), more likely to have injuries classified as severe TBIs and more likely to have accumulated more than one indicator of parenchymal injury as measured by the Composite Stroke Severity Scale (CSSS >1) than non-tracheostomized TBI patients. TBI patients with a tracheostomy were more likely to encounter serious complications such as sepsis, acute kidney injury (AKI), meningitis, or acute respiratory distress syndrome (ARDS). They were also more likely to necessitate an external ventricular drain (EVD) or decompressive hemicraniectomy (DHC) than TBI patients without a tracheostomy. Tracheostomy was also negatively associated with routine discharge. Procedural timing was assessed in 1,867 patients; older children (age >15 years) were more likely to undergo earlier placements (p < 0.001). Propensity score matching (PSM) comparing early versus late placement was completed by controlling for age, gender, and TBI severity. Those who were subjected to late tracheostomy (>9 days) were more likely to face complications such as AKI or deep vein thrombosis (DVT) as well as a host of respiratory conditions such as pulmonary embolism, aspiration pneumonitis, pneumonia, or ARDS. While the timing did not significantly impact mortality across the PSM cohorts, late tracheostomy was associated with increased length of stay (LOS) and ventilator dependence.

CONCLUSIONS

Tracheostomy, while necessary for some patients who have sustained a TBI, is itself associated with several risks that should be assessed in context of each individual patient's overall condition. Additionally, the timing of the intervention may significantly impact the trajectory of the patient's recovery. Early intervention may reduce the incidence of serious complications as well as length of stay and dependence on a ventilator and facilitate a timelier recovery.

Efficacy of 10 kHz spinal cord stimulation in complex regional pain syndrome: A retrospective analysis

INTRODUCTION

We examine the clinical efficacy of High Frequency 10 kHz (HF10) spinal cord stimulation (SCS) CRPS patients.

MATERIALS AND METHODS

This is a retrospective cohort study of SCS-naïve patients with CRPS treated with HF10-SCS after a successful trial. Patients were evaluated at 2 weeks, 6 weeks, 3 months, and 6 months post-operatively. Outcomes included mean numeric pain rating scale (NRS), mean NRS reduction, NRS percentage improvement (PI), patient reported subjective pain PI (Pain PI), and patients reporting > 50% benefit in symptoms. Pre and post-operative NRS were compared by ordinal regression analysis accounting for the patient's response to the SCS trial.

RESULTS

20 patients met inclusion criteria. 75% were female. Mean age 51 years. Baseline mean NRS was 6.1 for the cohort (1.7). Post-operatively, mean NRS decreased to 4.5 at 2 weeks (p = 0.077), 3.8 at 6 weeks (p = 0.034), 3.7 at 3 months (p = 0.307), and 4.4 at 6 months (p = 0.832). Mean NRS reduction and NRS PI is reported within. Pain PI was 25% at 2 weeks, 55% at 6 weeks, 54% at 3 months, and 53% at 6 months. Greater than 50% reduction in symptoms was reported in 25% of patients at 2 weeks, 85% at 6 weeks, 87% at 3 months, and 64% at 6 months.

CONCLUSIONS

HF10 SCS may represent an effective treatment option for reducing objective and subjective symptoms in CRPS that warrants further study.

Development of Machine Learning-Based Models to Predict Treatment Response to Spinal Cord Stimulation

BACKGROUND

Despite spinal cord stimulation's (SCS) proven efficacy, failure rates are high with no clear understanding of which patients benefit long term. Currently, patient selection for SCS is based on the subjective experience of the implanting physician.

OBJECTIVE

To develop machine learning (ML)-based predictive models of long-term SCS response.

METHODS

A combined unsupervised (clustering) and supervised (classification) ML technique was applied on a prospectively collected cohort of 151 patients, which included 31 features. Clusters identified using unsupervised K-means clustering were fitted with individualized predictive models of logistic regression, random forest, and XGBoost.

RESULTS

Two distinct clusters were found, and patients in the cohorts significantly differed in age, duration of chronic pain, preoperative numeric rating scale, and preoperative pain catastrophizing scale scores. Using the 10 most influential features, logistic regression predictive models with a nested cross-validation demonstrated the highest overall performance with the area under the curve of 0.757 and 0.708 for each respective cluster.

CONCLUSION

This combined unsupervised-supervised learning approach yielded high predictive performance, suggesting that advanced ML-derived approaches have potential to be used as a functional clinical tool to improve long-term SCS outcomes. Further studies are needed for optimization and external validation of these models.

Preoperative evaluation of coagulation status in neuromodulation patients

OBJECTIVE

The incidence of hemorrhage in patients who undergo deep brain stimulation (DBS) and spinal cord stimulation (SCS) is between 0.5% and 2.5%. Coagulation status is one of the factors that can predispose patients to the development of these complications. As a routine part of preoperative assessment, the authors obtain prothrombin time (PT), partial thromboplastin time (PTT), and platelet count. However, insurers often cover only PT/PTT laboratory tests if the patient is receiving warfarin/heparin. The authors aimed to examine their experience with abnormal coagulation parameters in patients who underwent neuromodulation.

METHODS

Patients who underwent neuromodulation (SCS, DBS, or intrathecal pump implantation) over a 9-year period and had preoperative laboratory values available were included. The authors determined abnormal values on the basis of a clinical protocol utilized at their practice, which combined the normal ranges of the laboratory tests and clinical relevance. This protocol had cutoff values of 12 seconds and 39 seconds for PT and PTT, respectively, and < 120,000 platelets/μl. The authors identified risk factors for these abnormalities and described interventions.

RESULTS

Of the 1767 patients who met the inclusion criteria, 136 had abnormal preoperative laboratory values. Five of these 136 patients had values that were misclassified as abnormal because they were within the normal ranges at the outside facility where they were tested. Fifty-one patients had laboratory values outside the ranges of our protocol, but the surgeons reviewed and approved these patients without further intervention. Of the remaining 80 patients, 8 had known coagulopathies and 24 were receiving warfarin/heparin. The remaining 48 patients were receiving other anticoagulant/antiplatelet medications. These included apixaban/rivaroxaban/dabigatran anticoagulants (n = 22; mean ± SD PT 13.7 ± 2.5 seconds) and aspirin/clopidogrel/other antiplatelet medications (n = 26; mean ± SD PT 14.4 ± 5.8 seconds). Eight new coagulopathies were identified and further investigated with hematological analysis.

CONCLUSIONS

New anticoagulants and antiplatelet medications are not monitored with PT/PTT, but they affect coagulation status and laboratory values. Although platelet function tests aid in a subset of medications, it is more difficult to assess the coagulation status of patients receiving novel anticoagulants. PT/PTT may provide value preoperatively.

Recommendations for Neuromodulation in Diabetic Neuropathic Pain

Over 50% of the 34 million people who suffer from diabetes mellitus (DM) are affected by diabetic neuropathy. Painful diabetic neuropathy (PDN) impacts 40–50% of that group (8.5 million patients) and is associated with a significant source of disability and economic burden. Though new neuromodulation options have been successful in recent clinical trials (NCT03228420), still there are many barriers that restrict patients from access to these therapies. We seek to examine our tertiary care center (Albany Medical Center, NY, USA) experience with PDN management by leveraging our clinical database to assess patient referral patterns and utilization of neuromodulation. We identified all patients with a diagnosis of diabetes type 1 (CODE: E10.xx) or diabetes type 2 (CODE: E11.xx) AND neuralgia/neuropathic pain (CODE: M79.2) or neuropathy (CODE: G90.09) or chronic pain (CODE: G89.4) or limb pain (CODE: M79.6) OR diabetic neuropathy (CODE: E11.4) who saw endocrinology, neurology, and/or neurosurgery from January 1, 2019, to December 31, 2019. We then determined which patients had received pain medications and/or neuromodulation to divide the cohort into three groups: no treatment, conservative treatment, and neuromodulation treatment. The cohorts were compared with chi-square or one-way ANOVA with multiple comparisons to analyze the differences. A total of 2,635 PDN patients were identified, of which 700 received no treatment for PDN, 1,906 received medication(s), and 29 received neuromodulation (intrathecal therapy, spinal cord stimulation, or dorsal root ganglion stimulation). The patients who received pain medications for PDN visited neurology more often than the pain specialists. Of the patients that received neuromodulation, 24 had seen neurology, 6 neurology pain, and 3 anesthesia pain. They averaged 2.78 pain medications prior to implant. Approximately 41% of the patients in the conservative management group were prescribed three or more medications. Of the 1,935 treated patients, only 1.5% of the patients received neuromodulation. The patients on three or more pain medications without symptomatic relief may be potential candidates for neuromodulation. An opportunity, therefore, exists to educate providers on the benefits of neuromodulation procedures.

Spinal Cord Stimulation to Treat Low Back Pain in Patients With and Without Previous Spine Surgery

OBJECTIVES

Little is known about the effects of spinal cord stimulation (SCS) on chronic low back pain (CLBP) patients with no history of previous spine surgery. Using our prospectively collected database, we evaluate improvements in patients with and without previous spine surgery one-year post SCS implantation.

MATERIALS AND METHODS

Subjects completed outcome metrics pre-operatively and one-year post-implantation including Numeric Rating Scale (NRS), McGill Pain Questionnaire (MPQ), Oswestry Disability Index (ODI), Beck's Depression Inventory (BDI), and Pain Catastrophizing Scale (PCS).

RESULTS

We enrolled 134 patients; 82 patients had previous spine surgery and 52 patients did not. At one-year post-SCS implantation, patients with previous spine surgery showed improvements in worst pain experienced, least pain experienced, average pain experienced, pain felt currently, MPQ, MPQ sensory, MPQ affective, PCS, PCS helplessness, PCS rumination, PCS magnification, ODI, and BDI scores (p < 0.001, p = 0.005, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p = 0.03, p = 0.01, p = 0.02, p < 0.001, p = 0.05, p < 0.001, p = 0.017, respectively). Likewise, patients without previous spine surgery showed improvements in worst pain experienced, least pain experienced, average pain experienced, pain felt currently, MPQ, MPQ sensory, PCS, PCS helplessness, PCS rumination, PCS magnification, ODI, and BDI scores (p < 0.001, p = 0.005, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p = 0.008, p < 0.001, p < 0.001, respectively). Patients without previous spine surgery showed greater improvements for average pain PCS helplessness (p = 0.01).

CONCLUSIONS

Patients with and without previous spine surgery showed similar improvements in pain intensity, pain quality, feelings of rumination and magnification, functional disability, and depression severity. SCS can improve CLBP regardless of whether patients have had previous spine surgery.

Safety of Deep Brain Stimulation Lead Placement on Patients Requiring Anticlotting Therapies

BACKGROUND

Limited studies exist to support the safety of performing neuromodulation surgeries in patients whose anticlotting medication has been held. Here, we assess the safety of performing deep brain stimulation (DBS) in this patient population.

METHODS

All consecutive DBS patients who underwent lead and battery placement/revision at our institution between 2011 and 2020 were included in this Institutional Review Board-approved prospective outcomes database. We retrospectively recorded adverse events occurring within 90 days of surgery.

RESULTS

The study included 226 patients who underwent 381 lead placements in 267 surgeries. Of the 267 surgeries included in this study, 176 (66%) were performed on patients not on anticoagulants and 89 (33%) cases were on patients on 1 drug. Two (0.7%) cases involved a patient taking 2 drugs. A total of 49 adverse events were seen. Thirteen occurred in patients taking anticoagulants. There was no difference in adverse event rate between patients on anticlotting medication and those not (χ² [1] = 1.523, P = 0.2171). No clot-related sequelae occurred in any patient. Three hemorrhages occurred, all in patients not on anticoagulants.

CONCLUSIONS

We found no increased risk of complications in patients routinely on anticlotting medication undergoing DBS lead placement. We show that our protocol was successful in balancing increased risks of bleeding and of thromboembolic events in this patient group.

Functional Use of Directional Local Field Potentials in the Subthalamic Nucleus Deep Brain Stimulation

Background

Directional deep brain stimulation (DBS) technology aims to address the limitations, such as stimulation-induced side effects, by delivering selective, focal modulation via segmented contacts. However, DBS programming becomes more complex and time-consuming for clinical feasibility. Local field potentials (LFPs) might serve a functional role in guiding clinical programming.

Objective

In this pilot study, we investigated the spectral dynamics of directional LFPs in subthalamic nucleus (STN) and their relationship to motor symptoms of Parkinson’s disease (PD).

Methods

We recorded intraoperative STN-LFPs from 8-contact leads (Infinity-6172, Abbott Laboratories, Illinois, United States) in 8 PD patients at rest. Directional LFPs were referenced to their common average and time-frequency analysis was computed using a modified Welch periodogram method. The beta band (13–35 Hz) features were extracted and their correlation to preoperative UPDRS-III scores were assessed.

Results

Normalized beta power (13–20 Hz) and normalized peak power (13–35 Hz) were found to be higher in anterior direction despite lack of statistical significance (p > 0.05). Results of the Spearman correlation analysis demonstrated positive trends with bradykinesia/rigidity in dorsoanterior direction (r = 0.659, p = 0.087) and with axial scores in the dorsomedial direction (r = 0.812, p = 0.072).

Conclusion

Given that testing all possible combinations of contact pairs and stimulation parameters is not feasible in a single clinic visit, spatio-spectral LFP dynamics obtained from intraoperative recordings might be used as an initial marker to select optimal contact(s).

Stereotactic EEG via multiple single-path omnidirectional trajectories within a single platform: institutional experience with a novel technique

OBJECTIVEStereotactic electroencephalography (SEEG) is being used with increasing frequency to interrogate subcortical, cortical, and multifocal epileptic foci. The authors describe a novel technique for SEEG in patients with suspected epileptic foci refractory to medical management.METHODSIn the authors' technique, standard epilepsy evaluation and neuroimaging are used to create a hypothesis-driven SEEG plan, which informs the 3D printing of a novel single-path, multiple-trajectory, omnidirectional platform. Following skull-anchor platform fixation, electrodes are sequentially inserted according to the preoperative plan. The authors describe their surgical experience and technique based on a review of all cases, adult and pediatric, in which patients underwent invasive epilepsy monitoring via SEEG during an 18-month period at Vanderbilt University Medical Center. Platform and anatomical variables influencing localization error were evaluated using multivariate linear regression.RESULTSUsing this novel technology, 137 electrodes were inserted in 15 patients with focal epilepsy with favorable recording results and no clinical complications. The mean entry point localization error was 1.42 mm (SD 0.98 mm), and the mean target point localization error was 3.36 mm (SD 2.68 mm). Platform distance, electrode trajectory angle, and intracranial distance, but not skull thickness, were independently associated with localization error.CONCLUSIONSThe multiple-trajectory, single-path, omnidirectional platform offers satisfactory accuracy and favorable clinical results, while avoiding cumbersome frames and prohibitive up-front costs associated with other SEEG technologies.

Early Experience With New Generation Deep Brain Stimulation Leads in Parkinson's Disease and Essential Tremor Patients

BACKGROUND

Newer generation deep brain stimulation (DBS) systems have recently become available in the United States. Data on real-life experience are limited. We present our initial experience incorporating newer generation DBS with Parkinson's disease (PD) and essential tremor (ET) patients. Newer systems allow for smart energy delivery and more intuitive programming and hardware modifications including constant current and directional segmented contacts.

METHODS

We compared six-month outcomes between 42 newer generation and legacy leads implanted in 28 patients. Two cohorts each included 7 PD patients with bilateral subthalamic nucleus (STN) stimulation and 7 ET patients with unilateral ventral intermediate nucleus (VIM) stimulation of the thalamus. All directional leads included 6172 Infinity 8-Channel Directional leads and Infinity internal pulse generators (Abbott Neuromodulation, Plano, TX, USA) and nondirectional leads included lead 3389 with Activa SC for VIM and PC for STN (Medtronic, Minneapolis, MN, USA).

RESULTS

Six-month outcomes for medication reduction and motor score improvements between new and legacy DBS systems in PD and ET patients were similar. Directionality was employed in 1/3 of patients. Therapeutic window (difference between amplitude when initial symptom relief was obtained and when intolerable side effects appeared with the contact being used) was significantly greater in new DBS systems in both PD (p = 0.005) and ET (p = 0.035) patients. The windows for new and legacy systems were 3.60 V ± 0.42 and 2.00 V ± 0.32 for STN and 3.06 V ± 0.44 and 1.85 V ± 0.28 for VIM, respectively.

DISCUSSION

The therapeutic window of newer systems, whether or not directionality was used, was significantly greater than that of the legacy system, which suggests increased benefit and programming options. Improvements in hardware and programming interfaces in the newer systems may also contribute to wider therapeutic windows. We expect that as we alter workflow associated with newer technology, more patients will use directionality, and amplitudes will become lower.

Confined Thalamic Deep Brain Stimulation in Refractory Essential Tremor

BACKGROUND

Thalamic ventral intermediate nucleus (VIM) deep brain stimulation (DBS) is an effective therapy for medication-refractory essential tremor (ET). However, 13-40% of patients with an initially robust tremor efficacy lose this benefit over time despite reprogramming attempts. At our institution, a cohort of ET patients with VIM DBS underwent implantation of a second anterior (ventralis oralis anterior; VOA) DBS lead to permit "confined stimulation." We sought to assess whether confined stimulation conferred additional tremor capture compared to VIM or VOA stimulation alone.

METHODS

Seven patients participated in a protocol-based programming session during which a video-recorded Fahn-Tolosa-Marin Part A (FTM-A) tremor rating scale was used in the following 4 DBS states: off stimulation, VIM stimulation alone, VOA stimulation alone, and dual lead (confined) stimulation.

RESULTS

The average (SD) baseline FTM-A off score was 17.6 (4.0). VIM stimulation alone lowered the average FTM-A total score to 6.9 (4.0). Confined stimulation further attenuated the tremor, reducing the total score to 5.7 (2.8).

CONCLUSIONS

Confined thalamic DBS can provide additional symptomatic benefits in patients with unsatisfactory tremor control from VIM or VOA stimulation alone.

A Novel Approach to Avoid Baclofen Withdrawal When Faced With Infected Baclofen Pumps

BACKGROUND

Intrathecal (IT) Baclofen is beneficial for spasticity, but if pumps become infected necessitating removal, baclofen withdrawal is difficult to manage and life-threatening. Furthermore there is no consistency between dosing and severity of withdrawal. Case reports detail full baclofen withdrawal at dosages of 260 μg/day.

OBJECTIVE

To demonstrate that in patients on stable IT baclofen for prolonged periods, externalizing a patient's original IT pump is a safe, effective way to wean IT doses.

METHODS

Here, we describe a technique of continuing IT baclofen when urgent pump removal is needed. Specifically, we remove the infected pump. Then using a new or existing lumbar drain based on extent of infection, we reconnect the pump after cleaning with betadine and administer therapy externally during IT weaning.

RESULTS

Hundred forty seven baclofen pumps were implanted or replaced within four years. Infections occurred in seven patients. We utilized this technique in five of seven patients. Mean IT dose at time of explant was 400.5 ± 285.3 μg/day. We titrated the dose by 20-50% per day based on clinical response over a mean of 6.2 ± 1.3 days. The catheter was removed at bedside once weaning was complete. No patients had any signs of withdrawal, excluding minimal spasticity increases while optimizing oral treatment.

CONCLUSION

Here, we show preliminary evidence that an externalized IT pump is an effective means of weaning IT baclofen when infection of the pump occurs. This treatment strategy warrants further investigation, but appears to be a safe and effective.

CONFLICT OF INTEREST

Dr. Pilitsis is a consultant for Medtronic, Boston Scientific, Nevro, Jazz Pharmaceuticals, Neurobridge Therapeutics, and Abbott and receives grant support from Medtronic, Boston Scientific, Abbott, Nevro, Jazz Pharmaceuticals, GE Global Research and NIH 1R01CA166379. She is medical advisor for Centauri and Karuna and has stock equity. Dr. Sukul receives consultant fees from Medtronic. Julia Prusik receives grant support from Jazz Pharmaceuticals.

Safety of Spinal Cord Stimulation in Patients Who Routinely Use Anticoagulants

Objective

We assess the safety of performing the epidural placement or revision of spinal cord stimulation (SCS) in patients whose anticoagulation has been held (termed "anticoagulant-suspended" patients) in accordance with the 2017 Neurostimulation Appropriateness Consensus Committee (NACC) guidelines.

Subjects

Patients undergoing SCS were included in this institutional review board-approved study.

Design

A retrospective analysis of a prospectively collected database was performed. Any adverse event occurring within 90 days after SCS lead placement/revision was included.

Results

A total of 225 patients who had a total of 239 surgeries including lead placement or lead revision were included; 182 patients were not on anticoagulants, 37 patients used one anticoagulant, and six patients used two or more anticoagulants. There were 13 adverse events. Anticoagulant use as a whole had no significant relationship to operative or postoperative adverse effects (χ2(1) = 1.613, P > 0.05). No anticoagulant on its own contributed significantly to adverse events; however, a small set of surgical cases showed a significantly greater incidence of adverse events for patients on enoxaparin used in combination with other anticoagulants (P < 0.05, N = 4).

Conclusions

This study is the first to demonstrate that anticoagulant-suspended patients have no increased risk of perioperative hemorrhagic or thromboembolic adverse effects following SCS surgery compared with nonanticoagulated patients. The findings of this study validate the safety of neuromodulation in anticoagulation-suspended patients, concurring with the findings of previously described case studies, which anecdotally described neuromodulation outcomes in patients whose anticoagulation regimen had been temporarily held.

Endoscope-assisted repair of CSF otorrhea and temporal lobe encephaloceles via keyhole craniotomy

OBJECTIVE Temporal lobe encephaloceles and cerebrospinal fluid otorrhea from temporal bone defects that involve the tegmen tympani and mastoideum are generally repaired using middle fossa craniotomy, mastoidectomy, or combined approaches. Standard middle fossa craniotomy exposes patients to dural retraction, which can lead to postoperative neurological complications. Endoscopic and minimally invasive techniques have been used in other surgeries to minimize brain retraction, and so these methods were applied to repair the lateral skull base. The goal of this study was to determine if the use of endoscopic visualization through a middle fossa keyhole craniotomy could effectively repair tegmen defects. METHODS The authors conducted a retrospective review of 6 cases of endoscope-assisted middle fossa repairs of tegmen dehiscences at a tertiary care medical center within an 18-month period. RESULTS All cases were successfully treated using a keyhole craniotomy with endoscopic visualization and minimal retraction. Surgical times did not increase. There were no major postoperative complications, recurrences of encephaloceles, or cerebrospinal fluid otorrhea in these patients. CONCLUSIONS Endoscopic visualization allows for smaller incisions and craniotomies and less risk of brain retraction injury without compromising repair integrity during temporal encephalocele and tegmen repairs.

Cranio-orbito-zygomatic approach for a previously coiled/recurrent giant MCA aneurysm in a hybrid angio/OR suite

We present surgical clipping of a giant middle cerebral artery aneurysm. The patient is a 64-year-old woman who suffered subarachnoid hemorrhage in 2005. She was treated with coiling of the aneurysm at an outside institution. She presented to our clinic with headaches and was found on angiography to have giant recurrence of the aneurysm. To allow adequate exposure for clipping, we performed the surgery through a cranio-orbito-zygomatic (COZ) skull base approach, which is demonstrated. The surgery was performed in an operating room/angiography hybrid suite allowing for high quality intraoperative angiography. The technique and room flow are also demonstrated. The video can be found here: http://youtu.be/eePcyOMi85M.

Medical and surgical management of spinal epidural abscess: a systematic review

OBJECT

Spinal epidural abscess (SEA) is a rare condition that has previously been treated with urgent surgical decompression and antibiotics. Recent availability of MRI makes early diagnosis possible and allows for the nonoperative treatment of SEA in select patients. The first retrospective review of medically and surgically managed SEA was published in 1999, and since that time several other retrospective institutional reports have been published. This study reviews these published reports and compares pooled data with historical treatment data.

METHODS

A PubMed keyword and Boolean search using ("spinal epidural abscess" OR "spinal epidural abscesses" AND [management OR treatment]) returned 429 results. Filters for the English language and publications after 1999 were applied, as the first study comparing operative and nonoperative management was published that year. Articles comparing operative to nonoperative treatment strategies for SEA were identified, and the references were further reviewed for additional articles. Studies involving at least 10 adult patients (older than 18 years) were included. Case reports, studies reporting either medical or surgical management only, studies not reporting indications for conservative management, or studies examining SEA as a result of a specific pathogen were excluded.

RESULTS

Twelve articles directly comparing surgical to nonsurgical management of SEA were obtained. These articles reported on a total of 1099 patients. The average age of treated patients was 57.24 years, and 62.5% of treated patients were male. The most common pathogens found in blood and wound cultures were Staphylococcus aureus (63.6%) and Streptococcus species (6.8%). The initial treatment was surgery in 59.7% of cases and medical therapy in 40.3%. This represented a significant increase in the proportion of medically managed patients in comparison with the historical control prior to 1999 (p < 0.05). Patients with no neurological deficits were significantly more likely to be treated medically than surgically (p < 0.05). There was no statistically significant difference overall between surgical and nonsurgical management, although several risk factors may predict failure of medical management.

CONCLUSIONS

Since the first reports of nonoperative treatment of SEA, there has been a substantial trend toward treating neurologically intact patients with medical management. Nevertheless, medical therapy fails in a fair number of cases involving patients with specific risk factors, and patients with these risk factors should be closely observed in consideration for surgery. Further research may help identify patients at greater risk for failure of medical therapy.

Use of a cyanoacrylate skin adhesive to reduce external ventricular drain infection rates

Object

Ventriculitis related to external ventricular drain (EVD) placement is a significant source of morbidity in neurological intensive care patients. Current rates of EVD-related infections range from 2% to 45% in the literature. The authors sought to determine if a 2-octyl cyanoacrylate adhesive would result in lower infection rate than standard semiocclusive dressings.

Methods

The authors tracked ventriculitis rates via CSF cultures among 259 patients whose EVD sites were dressed with sterile semiocclusive dressings and underwent routine sterile dressing exchanges every 48 hours. They analyzed data obtained in an additional 113 patients whose EVD sites were dressed one time with a surgical adhesive, 2-octyl cyanoacrylate.

Results

Ventriculitis rate in patients with standard bioocclusive dressings and wound care was 15.1%, whereas that in patients with a 2-octyl cyanoacrylate dressing was 3.54% (p = 0.002). Staphylococcus genus accounted for 79.5% of instances of ventriculitis among patients with bioocclusive dressings and routine wound care, whereas it accounted for 25.0% of the instances of ventriculitis among patients with a liquid polymer sealant dressing. A 90% reduction in Staphylococcus infection completely accounts for the observed effect (p = 0.04).

Conclusions

The one-time application of 2-octyl cyanoacrylate to EVD wounds and exit sites provided superior protection against EVD-related ventriculitis compared to conventional EVD-site wound care. Likely this protection results from a barrier to the entry of gram-positive skin flora along the EVD exit tract. The results should be validated in a randomized trial.

Surgical approaches to complex vascular lesions: the use of virtual reality and stereoscopic analysis as a tool for resident and student education

Virtual reality training for complex tasks has been shown to be of benefit in fields involving highly technical and demanding skill sets. The use of a stereoscopic three-dimensional (3D) virtual reality environment to teach a patient-specific analysis of the microsurgical treatment modalities of a complex basilar aneurysm is presented. Three different surgical approaches were evaluated in a virtual environment and then compared to elucidate the best surgical approach. These approaches were assessed with regard to the line-of-sight, skull base anatomy and visualisation of the relevant anatomy at the level of the basilar artery and surrounding structures. Overall, the stereoscopic 3D virtual reality environment with fusion of multimodality imaging affords an excellent teaching tool for residents and medical students to learn surgical approaches to vascular lesions. Future studies will assess the educational benefits of this modality and develop a series of metrics for student assessments.

Functional connectivity of the sensorimotor area in naturally sleeping infants

Patterns of cortical functional connectivity in normal infants were examined during natural sleep by observing the time course of very low frequency oscillations. Such oscillations represent fluctuations in blood oxygenation level and cortical blood flow thus allowing computation of neurophysiologic connectivity. Structural and resting-state information were acquired for 11 infants, with a mean age of 12.8 months, using a GE 1.5 T MR scanner. Resting-state data were processed and significant functional connectivity within the sensorimotor area was identified using independent component analysis. Unilateral functional connectivity in the developing sensory-motor cortices was observed. Power spectral analysis showed that slow frequency oscillations dominated the hemodynamic signal at this age, with, on average, a peak frequency for all subjects of 0.02 Hz. Our data suggest that there is more intrahemispheric than interhemispheric connectivity in the sensorimotor area of naturally sleeping infants. This non-invasive imaging technique, developed to allow reliable scanning of normal infants without sedation, enabled computation of neurophysiologic connectivity for the first time in naturally sleeping infants. Such techniques permit elucidation of the role of slow cortical oscillations during early brain development and may reveal critical information regarding the normative development and lateralization of brain networks across time.