Distinct Functional Connectivity Patterns for Intermittent Vs Constant Neuropathic Pain Phenotypes in Persistent Spinal Pain Syndrome Type 2 Patients.

Background: Chronic low back pain (cLBP) has been associated with alterations in brain functional connectivity (FC) but based upon heterogeneous populations and single network analyses. Our goal is to study a more homogeneous cLBP population and focus on multiple cross-network (CN) connectivity analysis. We hypothesize that within this population: 1) altered CN FC, involving emotion and reward/aversion functions are related to their pain levels and 2) altered relationships are dependent upon pain phenotype (constant neuropathic vs intermittent pain). Methods: In this case series, resting state fcMRI scans were obtained over a study duration of 60 months from 23 patients (13 constant neuropathic and 10 intermittent pain) with Persistent Spinal Pain Syndrome (PSPS Type 2) being considered for spinal cord stimulation (SCS) therapy at a single academic center. Images were acquired using a Discovery MR750 GE scanner. During the resting state acquisitions, they were asked to close their eyes and relax. The CN analysis was performed on 7 brain networks and compared to age-matched controls. Linear regression was used to test the correlation between CN connectivity and pain scores. Results: CN FC involving emotion networks (STM: striatum network index) was significantly lower than controls in all patients, regardless of pain phenotype (P < 0.003). Pain levels were positively correlated with emotional FC for intermittent pain but negatively correlated for constant pain. Conclusion: This is the first report of 1) altered CN FC involving emotion/reward brain circuitry in 2) a homogeneous population of cLBP patients with 3) two different pain phenotypes (constant vs intermittent) in PSPS Type 2 patients being considered for SCS. FC patterns were altered in cLBP patients as compared to controls and were characteristic for each pain phenotype. These data support fcMRI as a potential and objective tool in assessing pain levels in cLBP patients with different pain phenotypes.

Treatment of a Pial Arterial Venous Fistula in a Newborn: 2-Dimensional Operative Video.

Pial arterial venous fistulas (PAVFs) are rare vascular entities that occur with direct high-flow connections between pial arterial feeders and large veins without an intervening nidus.1-5 These vascular abnormalities can present in the pediatric population with high output heart failure.1 PAVFs can be treated with endovascular intervention, microvascular ligation, or a combination depending on the clinical scenario.4 Here, we present a case in which a newborn presented in high output heart failure because of a large left-sided middle cerebral artery fed PAVF. We performed a craniotomy for ligation of the PAVF to obliterate the arteriovenous shunting to improve her cardiac status and diminish her intracranial venous hypertension. Throughout the ligation, we used indocyanine green to localize the next appropriate vessels to ligate, allowing us to safely obliterate the anomalous vasculature and improve the patient's cardiac function. Postoperatively, the patient did well neurologically with improvements in cardiac function and near normalization of intracranial vasculature. The patient's guardians consented to the procedure and to the publication of her image.

Functional Connectivity Magnetic Resonance Imaging Sequences in Patients With Postsurgical Persistent Spinal Pain Syndrome Type 2 With Implanted Spinal Cord Stimulation Systems: A Safety, Feasibility, and Validity Study.

BACKGROUND: Chronic pain has been associated with alterations in brain connectivity, both within networks (regional) and between networks (cross-network connectivity). Functional connectivity (FC) data on chronic back pain are limited and based on heterogeneous pain populations. Patients with postsurgical persistent spinal pain syndrome (PSPS) type 2 are good candidates for spinal cord stimulation (SCS) therapy. We hypothesize that 1) FC magnetic resonance imaging (fcMRI) scans can be safely obtained in patients with PSPS type 2 with implanted therapeutic SCS devices and that 2) their cross-network connectivity patterns are altered and involve emotion and reward/aversion functions. MATERIALS AND METHODS: Resting-state (RS) fcMRI (rsfcMRI) scans were obtained from nine patients with PSPS type 2 implanted with therapeutic SCS systems and 13 age-matched controls. Seven RS networks were analyzed, including the striatum. RESULTS: Cross-network FC sequences were safely obtained on a 3T MRI scanner in all nine patients with PSPS type 2 with implanted SCS systems. FC patterns involving emotion/reward brain circuitry were altered as compared with controls. Patients with a history of constant neuropathic pain, experiencing longer therapeutic effects of SCS, had fewer alterations in their connectivity patterns. CONCLUSIONS: To our knowledge, this is the first report of altered cross-network FC involving emotion/reward brain circuitry in a homogeneous population of patients with chronic pain with fully implanted SCS systems, on a 3T MRI scanner. All rsfcMRI studies were safe and well tolerated by all nine patients, with no detectable effects on the implanted devices.

Magnetic resonance imaging-guided stereotactic laser ablation therapy for the treatment of pediatric epilepsy: a retrospective multiinstitutional study.

OBJECTIVE: The authors of this study evaluated the safety and efficacy of stereotactic laser ablation (SLA) for the treatment of drug-resistant epilepsy (DRE) in children. METHODS: Seventeen North American centers were enrolled in the study. Data for pediatric patients with DRE who had been treated with SLA between 2008 and 2018 were retrospectively reviewed. RESULTS: A total of 225 patients, mean age 12.8 ± 5.8 years, were identified. Target-of-interest (TOI) locations included extratemporal (44.4%), temporal neocortical (8.4%), mesiotemporal (23.1%), hypothalamic (14.2%), and callosal (9.8%). Visualase and NeuroBlate SLA systems were used in 199 and 26 cases, respectively. Procedure goals included ablation (149 cases), disconnection (63), or both (13). The mean follow-up was 27 ± 20.4 months. Improvement in targeted seizure type (TST) was seen in 179 (84.0%) patients. Engel classification was reported for 167 (74.2%) patients; excluding the palliative cases, 74 (49.7%), 35 (23.5%), 10 (6.7%), and 30 (20.1%) patients had Engel class I, II, III, and IV outcomes, respectively. For patients with a follow-up ≥ 12 months, 25 (51.0%), 18 (36.7%), 3 (6.1%), and 3 (6.1%) had Engel class I, II, III, and IV outcomes, respectively. Patients with a history of pre-SLA surgery related to the TOI, a pathology of malformation of cortical development, and 2+ trajectories per TOI were more likely to experience no improvement in seizure frequency and/or to have an unfavorable outcome. A greater number of smaller thermal lesions was associated with greater improvement in TST. Thirty (13.3%) patients experienced 51 short-term complications including malpositioned catheter (3 cases), intracranial hemorrhage (2), transient neurological deficit (19), permanent neurological deficit (3), symptomatic perilesional edema (6), hydrocephalus (1), CSF leakage (1), wound infection (2), unplanned ICU stay (5), and unplanned 30-day readmission (9). The relative incidence of complications was higher in the hypothalamic target location. Target volume, number of laser trajectories, number or size of thermal lesions, or use of perioperative steroids did not have a significant effect on short-term complications. CONCLUSIONS: SLA appears to be an effective and well-tolerated treatment option for children with DRE. Large-volume prospective studies are needed to better understand the indications for treatment and demonstrate the long-term efficacy of SLA in this population.

Vacuum-assisted elevation of pediatric ping-pong skull fractures: a case series and technical note.

OBJECTIVE: The management of children with ping-pong skull fractures may include observation, nonsurgical treatments, or surgical intervention depending on the age, clinical presentation, imaging findings, and cosmetic appearance of the patient. There have been 16 publications on nonsurgical treatment using negative pressure with various devices. Herein, the authors report their experience with vacuum-assisted elevation of ping-pong skull fractures and evaluate the variables affecting procedural outcomes. METHODS: The authors performed a retrospective chart review of all ping-pong skull fractures treated via vacuum-assisted elevation at the Children's Hospital of Wisconsin between 2013 and 2017. Data collected included patient age, head circumference, mode of injury, time to presentation, imaging findings, procedural details, treatment outcomes, and complications. RESULTS: Four neonates and 5 infants underwent vacuum-assisted elevation of moderate to severe ping-pong skull fractures during the study period. Modes of injury included birth-related trauma, falls, and blunt trauma. All patients had normal neurological examination findings and no evidence of intracranial hemorrhage. All fractures were deemed severe enough to require elevation by the treating neurosurgeon. All fractures involved the parietal bone. Skull depressions ranged from 23 to 62 mm in diameter and from 4 to 14 mm in depth. Bone thickness ranged from 0.6 to 1.8 mm. The time from fracture to intervention ranged from 7 hours to 8 days. The Kiwi OmniCup vacuum delivery system was used in all cases. Negative pressures were increased sequentially to a maximum of 500 mm Hg. A greater number of sequential vacuum applications was required for patients with a skull thickness greater than 1 mm at the site of depression and for those undergoing treatment more than 72 hours from fracture onset. Successful fracture elevation was attained in 7 of 9 patients. Two patients required subsequent surgical elevation of their fractures. Postprocedure imaging studies revealed no evidence of complications. CONCLUSIONS: Increasing bone thickness and time from fracture onset to intervention appeared to be the greatest limiting factors to the successful elevation of moderate to severe ping-pong fractures via this vacuum-assisted approach. This procedure is a well-tolerated option that should be considered prior to performing an open repair in cases deemed to require fracture elevation. Future efforts will focus on larger-volume studies to better delineate inclusion and exclusion criteria, and volumetric analysis for better fracture-to-suction device customization.

Magnetic resonance-guided stereotactic laser ablation therapy for the treatment of pediatric brain tumors: a multiinstitutional retrospective study.

OBJECTIVE: This study aimed to assess the safety and efficacy of MR-guided stereotactic laser ablation (SLA) therapy in the treatment of pediatric brain tumors. METHODS: Data from 17 North American centers were retrospectively reviewed. Clinical, technical, and radiographic data for pediatric patients treated with SLA for a diagnosis of brain tumor from 2008 to 2016 were collected and analyzed. RESULTS: A total of 86 patients (mean age 12.2 ± 4.5 years) with 76 low-grade (I or II) and 10 high-grade (III or IV) tumors were included. Tumor location included lobar (38.4%), deep (45.3%), and cerebellar (16.3%) compartments. The mean follow-up time was 24 months (median 18 months, range 3-72 months). At the last follow-up, the volume of SLA-treated tumors had decreased in 80.6% of patients with follow-up data. Patients with high-grade tumors were more likely to have an unchanged or larger tumor size after SLA treatment than those with low-grade tumors (OR 7.49, p = 0.0364). Subsequent surgery and adjuvant treatment were not required after SLA treatment in 90.4% and 86.7% of patients, respectively. Patients with high-grade tumors were more likely to receive subsequent surgery (OR 2.25, p = 0.4957) and adjuvant treatment (OR 3.77, p = 0.1711) after SLA therapy, without reaching significance. A total of 29 acute complications in 23 patients were reported and included malpositioned catheters (n = 3), intracranial hemorrhages (n = 2), transient neurological deficits (n = 11), permanent neurological deficits (n = 5), symptomatic perilesional edema (n = 2), hydrocephalus (n = 4), and death (n = 2). On long-term follow-up, 3 patients were reported to have worsened neuropsychological test results. Pre-SLA tumor volume, tumor location, number of laser trajectories, and number of lesions created did not result in a significantly increased risk of complications; however, the odds of complications increased by 14% (OR 1.14, p = 0.0159) with every 1-cm3 increase in the volume of the lesion created. CONCLUSIONS: SLA is an effective, minimally invasive treatment option for pediatric brain tumors, although it is not without risks. Limiting the volume of the generated thermal lesion may help decrease the incidence of complications.

Functional connectivity and structural analysis of trial spinal cord stimulation responders in failed back surgery syndrome.

BACKGROUND: Chronic pain has been associated with alterations in brain structure and function that appear dependent on pain phenotype. Functional connectivity (FC) data on chronic back pain (CBP) is limited and based on heterogeneous pain populations. We hypothesize that failed back surgery syndrome (FBSS) patients being considered for spinal cord stimulation (SCS) therapy have altered resting state (RS) FC cross-network patterns that 1) specifically involve emotion and reward/aversion functions and 2) are related to pain scores. METHODS: RS functional MRI (fMRI) scans were obtained for 10 FBSS patients who are being considered for but who have not yet undergone implantation of a permanent SCS device and 12 healthy age-matched controls. Seven RS networks were analyzed including the striatum (STM). The Wilcoxon signed-rank test evaluated differences in cross-network FC strength (FCS). Differences in periaqueductal grey (PAG) FC were assessed with seed-based analysis. RESULTS: Cross-network FCS was decreased (p<0.05) between the STM and all other networks in these FBSS patients. There was a negative linear relationship (R2 = 0.76, p<0.0022) between STMFCS index and pain scores. The PAG showed decreased FC with network elements and amygdala but increased FC with the sensorimotor cortex and cingulate gyrus. CONCLUSIONS: Decreased FC between STM and other RS networks in FBSS has not been previously reported. This STMFCS index may represent a more objective measure of chronic pain specific to FBSS which may help guide patient selection for SCS and subsequent management.

Care Bundle Approach to Minimizing Infection Rates after Neurosurgical Implants for Neuromodulation: A Single-Surgeon Experience.

INTRODUCTION: Implant-related infections carry a high morbidity. Infectious rates for neuromodulation implants range from 1% to 9% for deep brain stimulation (DBS), 0% to 10% for spinal cord stimulation (SCS) systems, and 3% to 15% for intrathecal (IT) pump systems. Meanwhile, studies of care bundles report infection rate reduction to 1.0% for SCS and 0.3% for cardiac implants. Herein, we evaluate the effectiveness of an infection prevention bundle (IPB) in minimizing infections after surgeries for neuromodulation implants. METHODS: An IPB focused on preoperative checklists, screening questionnaires, methicillin-resistant and methicillin-sensitive Staphylococcus aureus decolonization, weight-based antibiotic prophylaxis, strict draping and surgical techniques, and wound care education was implemented in our functional neurosurgery division in April 2015. We retrospectively reviewed all surgeries for implantation or replacement of SCS, DBS, and IT pump system components from March 2013 to October 2017. The patients were divided into pre-IPB and post-IPB groups. All procedures were performed by a single surgeon. Each surgical site was considered a unique surgical case. Infection rates were calculated for pre-IPB and post-IPB groups. RESULTS: A total of 688 patients underwent 1161 unique surgical procedures (222 DBS electrodes, 419 IPG, 203 SCS, 317 IT pumps) during the study period. There were 546 pre-IPB and 615 post-IPB surgical procedures. The pre-IPB infection rates were 0%, 1.3%, and 8.7% for SCS, DBS, and IT pumps, respectively. The post-IPB infection rates were 0%, 0.3%, and 1.8% for SCS, DBS, and IT pumps, respectively. CONCLUSIONS: Implementation of a standardized IPB approach reduced the number of infections for all neuromodulation implants studied. This approach can be adopted within any specialty to potentially decrease the incidence of implant-related infections.

Improvement of Hypothalamic Hamartoma-Related Psychiatric Disorder After Stereotactic Laser Ablation: Case Report and Review of Literature.

BACKGROUND: Hypothalamic hamartomas (HHs) are nonneoplastic congenital malformations associated with refractory epilepsy and behavioral disorders. Improvement in behavioral functioning following resection of HHs has been reported. Stereotactic laser ablation (SLA), a minimally invasive technique, has been used for the treatment of HH-related epilepsy. We report the case of child with an HH, gelastic seizures, and severe psychiatric dysfunction who was successfully treated via SLA therapy. CASE DESCRIPTION: The patient was an 11-year-old female with a history of central hypothyroidism, precocious puberty, and localization-related epilepsy thought to be secondary to an HH. She had a significant psychiatric history including attention deficit hyperactivity disorder, depressed mood, impulsivity, threatening behavior, and suicidal ideation requiring management with dexmethylphenidate, bupropion, and aripiprazole. Seizure onset occurred at age 7, and her semiology included nighttime hypermotor seizures and uncontrollable laughing spells thought to be gelastic seizures. Her hypermotor seizures were successfully managed with oxcabazepine monotherapy, but she continued to have several weekly laughing spells and self-harming behavior. Her HH was successfully treated via SLA. Postoperatively, she remained neurologically intact and was discharged the next day. At her 6-month follow-up, she had a markedly improved affect and general mood. At 3 years postprocedure, she remains seizure free and has been weaned off her antiepileptic and antipsychotic medications. CONCLUSIONS: Severe behavioral dysfunction in the setting of an HH may constitute an indication for surgical intervention. The outcome of this case suggests there may be a role for SLA in the management of HH-related psychiatric dysfunction, even in patients with good seizure control.

Spheno-Orbital Aneurysmal Bone Cyst in a 10-Month-Old Infant.

BACKGROUND: Aneurysmal bone cysts are benign bone lesions affecting long bones and vertebrae; only 2%-6% have cranial involvement, and even fewer show sphenoid or intraorbital involvement. Gross total resection is the treatment of choice. CASE DESCRIPTION: A 10-month-old girl presented with unilateral proptosis and no neurologic deficits. Imaging studies revealed an extensive right-sided skull base cystic lesion centered on the sphenoid wing with extension into the orbit anteriorly and the pterygoid plates inferiorly. She underwent a modified osteoplastic orbitozygomatic craniotomy for resection of the extradural tumor. Postoperative imaging showed successful decompression of the intraorbital contents with no residual tumor. She remained neurologically intact and was discharged on postoperative day 2. Histologic examination revealed the lesion to be consistent with an aneurysmal bone cyst. At 3-month follow-up, her proptosis had resolved, neurologic examination was nonfocal, and there was no radiographic evidence of recurrence. CONCLUSIONS: To our knowledge, this is the youngest patient reported to have a spheno-orbital aneurysmal bone cyst. Such lesions in this age group present practical management challenges. By using a modified osteoplastic orbitozygomatic craniotomy, we achieved a gross total resection with minimal brain retraction, avoided the need for plating and suturing at the orbital rim, maintained a vascularized bone flap that is less susceptible to infection, and maintained normal temporalis muscle anatomy with excellent cosmetic results.

Split laminotomy versus conventional laminotomy: postoperative outcomes in pediatric patients.

OBJECTIVE Split laminotomy is a technique for accessing the spinal canal from the posterior midline that minimizes muscle dissection and bone removal. Benefits of this approach in minimizing postoperative pain and muscle atrophy in the adult population have been reported, but pediatric data are limited. Herein, the authors evaluate the benefits of the split laminotomy technique in pediatric patients. METHODS Data obtained in patients who underwent posterior spine surgery at Children's Hospital of Wisconsin for an intradural midline pathology between April 2008 and June 2015 were reviewed retrospectively. Each patient was assigned to one of two groups, the split-laminotomy or conventional-laminotomy group. The primary outcomes assessed were mean daily pain score, total opioid use over a period of 72 hours after surgery, and the degree of paraspinal muscle atrophy and fat infiltration found on short-term (1-4 months) and long-term (1-4 years) follow-up spine MRI studies. RESULTS A total of 117 patients underwent lumbar-level surgery (83 conventional laminotomy, 34 split laminotomy), and 8 patients underwent thoracic-level surgery (4 in each group). No significant difference in the mean daily pain scores between groups was found. The daily opioid use was significantly lower in the split-laminotomy group on postoperative day 0 (POD0) and POD1 but not on POD2 (p = 0.01, 0.01, and 0.10, respectively). The total opioid use over the 72-hour postoperative period was significantly lower in the split-laminotomy group (p = 0.0008). The fat/muscle ratio was significantly higher in both the short-term and long-term follow-up periods in the conventional-laminotomy group (p = 0.01 and 0.0002, respectively). The rate of change of paraspinal muscle fat infiltration was significantly lower in the split-laminotomy group than in the conventional-laminotomy group (p = 0.007). The incidence of complications was not significantly different between groups (p = 0.08). CONCLUSIONS This study was of the largest series reported thus far of pediatric patients who underwent split laminotomy and the only controlled study that has involved children. The authors' results reinforce the short-term benefit of split laminotomy in minimizing acute postoperative pain and long-term benefits of decreasing muscle atrophy and fatty degeneration, which are known to be associated with the development of chronic pain and spinal instability. Additional efforts for assessing long-term effects in the development of chronic pain, spinal instability, and spinal deformity are still necessary.

Imaging Evaluation of Degenerative Cervical Myelopathy: Current State of the Art and Future Directions.

Degenerative cervical myelopathy (DCM) is a common neurologic condition that is often treated with surgery. Imaging plays a central role in the management of DCM, including diagnosis, preoperative planning, postoperative assessment, and prognostication. Radiographs, CT, and MRI offer unique and complementary assessments, and all have important uses in current clinical practice. Emerging microstructural and functional MRI techniques have the potential to have a major impact, potentially transforming practice by offering earlier and more accurate diagnosis, monitoring for deterioration, and prediction of outcomes. In the future, it can be expected that imaging will play an even greater role in DCM management.

Effects of deep brain stimulation on vocal fold immobility in Parkinson's disease.

BACKGROUND: Vocal fold (VF) immobility is a rare, potentially fatal complication of advanced Parkinson's disease (PD). Previous reports suggest that subthalamic nucleus deep brain stimulation (STN-DBS) may influence laryngeal function, yet the role of STN-DBS on VF immobility remains unexplored. CASE DESCRIPTION: We report a case of a patient with advanced PD and bilateral VF immobility ultimately requiring a tracheostomy. To assess the effects of STN-DBS on vocal cord function and to correlate these effects with peripheral motor symptoms at different stimulation settings, the patient was evaluated before and after initiation of bilateral STN-DBS. Measures included direct observation of VF mobility via transnasal laryngoscopy, levodopa equivalent dose of anti-PD medication, and motor scores. High frequency (150 Hz) STN-DBS resulted in improved motor scores, reduced medication requirement, and modestly improved right VF abduction although insufficient for safe decannulation. Low frequency (60 Hz) stimulation resulted in lower motor scores, but without worsening VF abduction. CONCLUSIONS: STN-DBS may play an important role in the neuromodulation of PD-induced laryngeal dysfunction, including VF mobility. Characterization of these axial symptoms is important when programming and evaluating responsiveness to DBS.

Non-Infectious Peri-Electrode Edema and Contrast Enhancement Following Deep Brain Stimulation Surgery.

BACKGROUND: Dramatic radiographic abnormalities seen after electrode placement (DRAAEP) in deep brain stimulation (DBS) surgery is rare and it has not been associated with infection or hemorrhage. It has consisted of peri-electrode low-attenuation signals on CT scans and extensive T2-hyperintense signals without associated contrast enhancement (CE) on MRI scans. OBJECTIVE: Report on the management of a patient with Parkinson's disease (PD) presenting with a seizure and findings of DRAAEP with positive CE 12 days after the placement of a subthalamic nucleus (STN) DBS electrode. METHODS: Head CT and contrasted brain MRI scans were completed on presentation. Standard laboratory work up was obtained to evaluate for infection. Operative exploration deep to the burr-hole site surrounding the electrode was performed and cultures were obtained. Serial contrasted MRI scans were completed to determine the abnormal signal duration. RESULTS: A MRI revealed extensive T2-hyperintensity and positive CE concentrated around the burr-hole site surrounding the electrode. Intraoperative exploration revealed no evidence of infection and electrode revision was avoided. There was near resolution of the abnormal T2 signal and CE at six weeks from detection. The patient remained without signs of intracranial infection and responded well to DBS. CONCLUSION: To our knowledge, this is the first reported case of DRAAEP with positive gadolinium enhancement. Despite the extensive contrast enhancement, these DRAAEP appear to remain benign transient events that, in the absence of clinical signs of infection or neurologic decline, may warrant no further aggressive intervention such as hardware removal.