Treatment of sacroiliac joint laxity-induced coronal imbalance with the kickstand rod technique.

BACKGROUND: Considerations of the sacroiliac joint (SIJ) and its role in causing lower back and limb pain have taken a secondary role ever since Mixter and Barr's hallmark article in 1934 on the herniated nucleus pulposus. However, recent literature has highlighted the contribution of sacroiliac joint degeneration in the development of failed back surgery syndrome (FBSS), especially in patients undergoing lumbar or lumbosacral spinal fusion surgeries. Many reports have studied the anatomy, physiology, and clinical significance of the sacroiliac joint, but none have linked its dysfunction with other spinal deformities. CASE DESCRIPTION: A 63-year-old female with a history of multiple complex instrumented spinal fusions presented to our institution with progressive leftward coronal imbalance despite successful arthrodesis from T3 through S1. She was initially treated with decompression and reimplantation, but adjacent segment disease at the SIJ led to laxity, distal failure, and a worsening coronal deformity. A mechanical fall after her decompression surgery led to a dramatically increased coronal imbalance, which was ultimately treated using Lenke's kickstand rod technique. At 3.5 years follow up, the patient's coronal balance remains stable. CONCLUSION: Few studies have related SIJ degeneration and laxity with spinal deformity. Our case describes SIJ degeneration that evolved to joint laxity, which ultimately produced a leftward coronal imbalance according to the adjacent segment disease mechanism. Additionally, we describe the use of a kickstand rod to effectively correct the coronal imbalance, reduce pain levels, promote SIJ arthrodesis, and prevent further SIJ-related issues without significant complications over 3 years post-operation.

Functional Disruptions of the Brain in Low Back Pain: A Potential Imaging Biomarker of Functional Disability.

Chronic low back pain (LBP) is one of the leading causes of disability worldwide. While LBP research has largely focused on the spine, many studies have demonstrated a restructuring of human brain architecture accompanying LBP and other chronic pain states. Brain imaging presents a promising source for discovering noninvasive biomarkers that can improve diagnostic and prognostication outcomes for chronic LBP. This study evaluated graph theory measures derived from brain resting-state functional connectivity (rsFC) as prospective noninvasive biomarkers of LBP. We also proposed and tested a hybrid feature selection method (Enet-subset) that combines Elastic Net and an optimal subset selection method. We collected resting-state functional MRI scans from 24 LBP patients and 27 age-matched healthy controls (HC). We then derived graph-theoretical features and trained a support vector machine (SVM) to classify patient group. The degree centrality (DC), clustering coefficient (CC), and betweenness centrality (BC) were found to be significant predictors of patient group. We achieved an average classification accuracy of 83.1% (p < 0.004) and AUC of 0.937 (p < 0.002), respectively. Similarly, we achieved a sensitivity and specificity of 87.0 and 79.7%. The classification results from this study suggest that graph matrices derived from rsFC can be used as biomarkers of LBP. In addition, our findings suggest that the proposed feature selection method, Enet-subset, might act as a better technique to remove redundant variables and improve the performance of the machine learning classifier.

Multi-modal biomarkers of low back pain: A machine learning approach.

Chronic low back pain (LBP) is a very common health problem worldwide and a major cause of disability. Yet, the lack of quantifiable metrics on which to base clinical decisions leads to imprecise treatments, unnecessary surgery and reduced patient outcomes. Although, the focus of LBP has largely focused on the spine, the literature demonstrates a robust reorganization of the human brain in the setting of LBP. Brain neuroimaging holds promise for the discovery of biomarkers that will improve the treatment of chronic LBP. In this study, we report on morphological changes in cerebral cortical thickness (CT) and resting-state functional connectivity (rsFC) measures as potential brain biomarkers for LBP. Structural MRI scans, resting state functional MRI scans and self-reported clinical scores were collected from 24 LBP patients and 27 age-matched healthy controls (HC). The results suggest widespread differences in CT in LBP patients relative to HC. These differences in CT are correlated with self-reported clinical summary scores, the Physical Component Summary and Mental Component Summary scores. The primary visual, secondary visual and default mode networks showed significant age-corrected increases in connectivity with multiple networks in LBP patients. Cortical regions classified as hubs based on their eigenvector centrality (EC) showed differences in their topology within motor and visual processing regions. Finally, a support vector machine trained using CT to classify LBP subjects from HC achieved an average classification accuracy of 74.51%, AUC = 0.787 (95% CI: 0.66-0.91). The findings from this study suggest widespread changes in CT and rsFC in patients with LBP while a machine learning algorithm trained using CT can predict patient group. Taken together, these findings suggest that CT and rsFC may act as potential biomarkers for LBP to guide therapy.

Transfacet Minimally Invasive Transforaminal Lumbar Interbody Fusion With an Expandable Interbody Device-Part I: 2-Dimensional Operative Video and Technical Report.

BACKGROUND: Advances in operative techniques and minimally invasive technologies have evolved to maximize patient outcomes and radiographic results, while reducing morbidity and recovery time. OBJECTIVE: To describe the operative technique for a transfacet minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) as a proposed modification to the standard approach MIS-TLIF. METHODS: We present the case of a 72-yr-old man with left-sided lumbar radiculopathy. Preoperative imaging demonstrated degenerative lumbar anterolisthesis at L4-5, with associated canal and neuroforaminal stenosis. The patient underwent transfacet MIS-TLIF at L4-L5. We describe the preoperative planning, patient positioning, incision and dissection, pedicle screw insertion, transfacet approach to the working access corridor, discectomy, interbody device placement, fixation, and closure. RESULTS: The transfacet MIS-TLIF utilizes 3 key techniques to safely maximize surgical correction: (1) a limited bony resection based on the superior articular process, leaving the medial inferior articular process, lateral superior articular process, and rostral pars intact, providing a working bony corridor that protects the traversing and exiting nerve roots; (2) decortication and release of the contralateral facet joint to provide additional capacity for indirect decompression and provide the first point of osseous fusion; and (3) placement of an expandable interbody device that provides additional indirect decompression to the working side and contralateral foramen. CONCLUSION: The transfacet MIS-TLIF uniquely leverages a bony working corridor to access the disc space for discectomy and interbody placement. Transfacet MIS-TLIF is a feasible solution for lumbar spinal reconstruction to maximize direct and indirect decompression of the neuroforamina and central spinal canal in patients with lumbar degenerative diseases and low-grade spondylolisthesis.

Transfacet Minimally Invasive Transforaminal Lumbar Interbody Fusion With an Expandable Interbody Device-Part II: Consecutive Case Series.

BACKGROUND: Advances in operative techniques and instrumentation technology have evolved to maximize patient outcomes following minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). The transfacet MIS-TLIF is a modified approach to the standard MIS-TLIF that leverages a bony working corridor to access the disc space for discectomy and interbody device placement. OBJECTIVE: To evaluate clinical and radiographic results following transfacet MIS-TLIF using an expandable interbody device. METHODS: We performed a retrospective review of consecutive patients who underwent transfacet MIS-TLIF for degenerative lumbar spondylolisthesis. Patient-reported outcome measures for pain and disability were assessed. Sagittal lumbar segmental parameters and regional lumbopelvic parameters were assessed on upright lateral radiographs obtained preoperatively and during follow-up. RESULTS: A total of 68 patients (61.8% male) underwent transfacet MIS-TLIF at 74 levels. The mean age was 63.4 yr and the mean follow-up 15.2 mo. Patients experienced significant short- and long-term postoperative improvements on the numeric rating scale for low back pain (-2.3/10) and Oswestry Disability Index (-12.0/50). Transfacet MIS-TLIF was associated with an immediate and sustained reduction of spondylolisthesis, and an increase in index-level disc height (+0.71 cm), foraminal height (+0.28 cm), and segmental lordosis (+6.83°). Patients with preoperative hypolordosis (<40°) experienced significant increases in segmental (+9.10°) and overall lumbar lordosis (+8.65°). Pelvic parameters were not significantly changed, regardless of preoperative alignment. Device subsidence was observed in 6/74 (8.1%) levels, and fusion in 50/53 (94.3%) levels after 12 mo. CONCLUSION: Transfacet MIS-TLIF was associated with clinical improvements and restoration of radiographic sagittal segmental parameters. Regional alignment correction was observed among patients with hypolordosis at baseline.

Modular cervical plate system for adjacent segment disease.

BACKGROUND: Adjacent-level disease after anterior cervical discectomy and fusion (ACDF) occurs in a significant proportion of patients and frequently requires revision operation. Methods using traditional plates typically require removal of the plate with anecdotally increased operative-time and morbidity. We review our experience in treating symptomatic adjacent-segment disease using both traditional plate removal and modular-plate system which allows for add-on plate components rather than removal of the entire plate. METHODS: Authors compared 64 patients with revision surgery using modular-plate system for adjacent-segment disease compared to 2-cohorts: 1) patients with traditional plate-removal; and 2) patients with no prior plate. Clinical data included demographics, original surgery, presentation, current surgery, use of modular system, need for preoperative computed-topography, operative-time, blood loss, hospital stay, complications, length of dysphagia, neck disability index and time-until-fusion. RESULTS: Modular cervical plate system was utilized to prevent exposure and removal of the entire plate. The terminal portion of the plate was exposed and the distal module was removed. Following the discectomy/arthrodesis, a module-plate extension was added onto the previous plate for extension of the prior instrumentation. Preoperative planning computed-topography was required in 26% of plate-removal and 17% of modular-plate cases. Revision surgery with no prior plate had reduced operative-time (77.0±18.1 min) when compared with plate removal (103.8±46.2 min; P<0.01). Blood-loss was lower for modular-plate system (38.3±20.4 mL) and no prior plate (38.4±12.6 mL) versus plate removal (78.2±65.9 mL, P<0.01). Hospital stay was similar for all groups. No complications were experienced with modular-plate revision but plate removal and revision after no prior plate carried 7.7% and 10.5% complication rates, respectively. There was a trend towards lower dysphagia and neck disability index with modular-plate revision. CONCLUSIONS: Use of modular cervical plate system allows for extension of a plate and reduces morbidity when treating adjacent-segment disease.

Project management for developing a spine "enhanced recovery after surgery" program in a large university-affiliated hospital.

Enhanced recovery after surgery (ERAS) programs for spine surgery have been developed throughout Europe and the United States leading to reduced hospital stay lengths, reduced opioid consumption, and faster return to activities of daily living and exercise. Development and execution of an ERAS spine program require commitment from the physician practice and collaborative hospital along with commitments from the entire health care team. Navigating this process can be a daunting task for a surgeon, whose traditional training involves no project management. Here we review our experience in the development of an ERAS program at a major academic medical institution and tertiary-care hospital in the USA from a program management perspective. In this manuscript, we provide the language and an outline to educate a surgeon on the project management processes needed to develop and initiate a pilot spine ERAS program.

Validation of the Disabilities of the Arm, Shoulder, and Hand in Patients Undergoing Cervical Spine Surgery.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To evaluate the performance and convergent validity of the disabilities of the arm, shoulder, and hand (DASH) in comparison with the visual analog scale (VAS) for pain, and neck disability index (NDI) in patients undergoing cervical spine surgery. SUMMARY OF BACKGROUND DATA: Neck-specific disability scales do not adequately assess concurrent upper extremity involvement in patients with cervical spine disorders. The DASH is a patient-reported outcomes (PRO) instrument designed to measure functional disability due to upper extremity conditions but has additionally been shown to perform well in patients with neck disorders. METHODS: We identified patients who underwent cervical spine surgery at our institution between 2013 and 2016. We collected demographic information, clinical characteristics, and PRO measures-DASH, VAS, NDI-preoperatively, as well as early and late postoperatively. We calculated descriptive statistics and changes from baseline in PROs. Correlation coefficients were used to quantify the association between PRO measures. The analysis was stratified by radiculopathy and myelopathy diagnoses. RESULTS: A total of 1046 patients (52.8% male) with PROs data at baseline were included in the analysis. The mean age at surgery ±â€ŠSD was 57.2 ±â€Š11.3 years, and postoperative follow-up duration 12.7 ±â€Š10.7 months. The most common surgical procedure was anterior cervical discectomy and fusion (71.1%). Patients experienced clinically meaningful postoperative improvements in all PRO measures. The DASH showed moderate positive correlations with VAS preoperatively (Spearman rho = 0.43), as well as early (rho = 0.48) and late postoperatively (rho = 0.60). DASH and NDI scores were strongly positively correlated across operative states (Preoperative rho = 0.74, Early Postoperative rho = 0.78, Late Postoperative rho = 0.82). Stratified analysis by preoperative diagnosis showed similar within-groups trends and pairwise correlations. However, radiculopathy patients experienced larger magnitude early and late change scores. CONCLUSION: The DASH is a valid and responsive PRO measure to evaluate disabling upper extremity involvement in patients undergoing cervical spine surgery. LEVEL OF EVIDENCE: 3.

Patient-Reported Outcomes Measurement Information System physical function and pain interference in spine surgery.

OBJECTIVEThe Patient-Reported Outcomes Measurement Information System (PROMIS) is an adaptive, self-reported outcomes assessment tool that utilizes item response theory and computer adaptive testing to efficiently and precisely evaluate symptoms and perceived health status. Efforts to implement and report PROMIS outcomes in spine clinical practice remain limited. The objective of this retrospective cohort study is to evaluate the performance and psychometric properties of PROMIS physical function (PF) and pain interference (PI) among patients undergoing spine surgery.METHODSThe authors identified all patients who underwent spine surgery at their institution between 2016 and 2018, and for whom there was retrievable PROMIS data. Descriptive statistics were calculated to summarize demographics, operative characteristics, and patient-reported outcomes. Assessments were evaluated preoperatively, and postoperatively within 2 months (early), 6 months (intermediate), and up to 2 years (late). Pairwise change scores were calculated to evaluate within-subjects differences and construct responsiveness over time. Pearson's correlation coefficients were used to evaluate the association between PROMIS PF and PI domains. Subgroup analysis was performed based on the primary diagnoses of cervical radiculopathy, cervical myelopathy, or lumbar degenerative disease.RESULTSA total of 2770 patients (1395 males, 50.4%) were included in the analysis. The mean age at the time of surgery was 57.3 ± 14.4 years. Mean postoperative follow-up duration was 7.6 ± 6.2 months. Preoperatively, patients scored an average 15.1 ± 7.4 points below the normative population (mean 50 ± 10 points) in PF, and 15.8 ± 6.8 points above the mean in PI. PROMIS PF required a mean of 4.1 ± 0.6 questions and median 40 seconds (interquartile range [IQR] 29-58 seconds) to be completed, which was similar to PI (median 4.3 ± 1.1 questions and 38 seconds [IQR 27-59 seconds]). Patients experienced clinically meaningful improvements in PF and PI, which were sustained throughout the postoperative course. PROMIS instruments were able to capture anticipated changes in PF and PI, although to a lesser degree in PF early postoperatively. There was a strong negative correlation between PROMIS PF and PI scores at baseline (Pearson's r = -0.72) and during follow-up appointments (early, intermediate, and late |r| > 0.6, each). Subgroup analysis demonstrated similar results within diagnostic groups compared to the overall cohort. However, the burden of PF limitations and PI was greater within the lumbar spine disease subgroup, compared to patients with cervical radiculopathy and myelopathy.CONCLUSIONSPatients receiving care at a tertiary spine surgery outpatient clinic experience significant overall disability and PI, as measured by PROMIS PF and PI computer adaptive tests. PROMIS PF and PI health domains are strongly correlated, responsive to changes over time, and facilitate time-efficient evaluations of perceived health status outcomes in patients undergoing spine surgery.

Population-based approaches to treatment and readmission after spinal cord injury.

BACKGROUND: Recent studies in surgical and non-surgical specialties have suggested that patients admitted on the weekend may have worse outcomes. In particular, patients with stroke and acute cardiovascular events have shown worse outcomes with weekend treatment. It is unclear whether this extends to patients with spinal cord injury (SCI). This study was designed to evaluate factors for readmission after index hospitalization for spinal cord injury. METHODS: This cohort was constructed from the State Inpatient Databases of California, New York, and Florida. For this study 14,396 patients with SCI were identified. The primary outcome measure evaluated was 30-day readmission. Secondary measures include in-hospital complications. Univariate and multivariate analysis were utilized to evaluate covariates. c2, Fisher's exact, and linear, logistic, and modified Poisson regression methods were utilized for statistical analysis. Propensity score methods were used with matched pairs analysis performed by the McNemar's Test. RESULTS: Weekend admission was not associated with increased 30- day readmission rates in multivariate analysis. Race and discharge to a facility (RR 1.60 [1.43-1.79]) or home with home care (RR 1.23 [1.07-1.42]), were statistically significant risk factors for readmission. Payor status did not affect rates of readmission. In propensity score matched pairs analysis, weekend admission was not associated with increased odds of 30-day readmission (OR 1.04 [0.89-1.21]). Patients admitted to high volume centers had significantly lower risk of readmission when compared with patients admitted to low volume centers. CONCLUSIONS: Our results suggest that the weekend effect, described previously in other patient populations, may not play as important a role in patients with SCI.

Readmission after spinal cord injury: analysis of an institutional cohort of 795 patients.

BACKGROUND: Recent studies in other fields have suggested that healthcare on the weekend may have worse outcomes. In particular, patients with stroke and acute cardiovascular events have shown worse outcomes with weekend treatment. It is unclear whether this extends to patients with spinal cord injury. This study was designed to evaluate factors for readmission after index hospitalization for spinal cord injury. METHODS: A total of 795 consecutive patients over an 11-year period were analyzed. After excluding patients with chronic spinal cord injury and surgical care at an outside hospital, 745 patients remained. The primary outcome measure evaluated was 30-day readmission. Secondary measures include perioperative complications, readmission rate when discharged on the weekend, and the effect of race and insurance status on readmission rate. Univariate and multivariate analysis were utilized to evaluate the covariates collected. The χ2 test, Fisher's exact test, and linear and logistic regression methods were utilized for statistical analysis. RESULTS: A total of 745 patients were analyzed after exclusions. Payer status did not affect length of stay, ICU length of stay, or perioperative complications. Neither weekend admission nor weekend operation affected length of stay, ICU length of stay, or readmission by 30 days. Patients undergoing weekend surgical treatment had lower perioperative complication rates (2.2% vs. 6.5% on weekday, P<0.01). Discharge on the weekend was associated with a significantly lower rate of readmission by 30 days (OR=0.07, 95% CI: 0.009-0.525, P<0.005). Payer status was associated with 30-day readmission (P<0.005). Patients with Medicare (20.8%) and Medicaid (20.1%) showed higher rates of readmission than patients with other payers. 21.1% of African-American patients were readmitted, versus 10.2% of other patients (Odds ratio: 2.2, 95% confidence interval 1.36-3.27, P<0.001). Correcting for payer status lessened but did not eliminate the effect of race on readmission. CONCLUSIONS: Weekend admission did not increase perioperative complications or hospital length of stay. After discharge, patients with Medicaid and Medicare show higher rates of 30-day readmission, as do African-American patients. The effect of race on readmission is multifactorial, and may partially explained by the increased rate of Medicaid coverage in African-Americans in our institutions catchment area.

Spinal Cord Injury Disrupts Resting-State Networks in the Human Brain.

Despite 253,000 spinal cord injury (SCI) patients in the United States, little is known about how SCI affects brain networks. Spinal MRI provides only structural information with no insight into functional connectivity. Resting-state functional MRI (RS-fMRI) quantifies network connectivity through the identification of resting-state networks (RSNs) and allows detection of functionally relevant changes during disease. Given the robust network of spinal cord afferents to the brain, we hypothesized that SCI produces meaningful changes in brain RSNs. RS-fMRIs and functional assessments were performed on 10 SCI subjects. Blood oxygen-dependent RS-fMRI sequences were acquired. Seed-based correlation mapping was performed using five RSNs: default-mode (DMN), dorsal-attention (DAN), salience (SAL), control (CON), and somatomotor (SMN). RSNs were compared with normal control subjects using false-discovery rate-corrected two way t tests. SCI reduced brain network connectivity within the SAL, SMN, and DMN and disrupted anti-correlated connectivity between CON and SMN. When divided into separate cohorts, complete but not incomplete SCI disrupted connectivity within SAL, DAN, SMN and DMN and between CON and SMN. Finally, connectivity changed over time after SCI: the primary motor cortex decreased connectivity with the primary somatosensory cortex, the visual cortex decreased connectivity with the primary motor cortex, and the visual cortex decreased connectivity with the sensory parietal cortex. These unique findings demonstrate the functional network plasticity that occurs in the brain as a result of injury to the spinal cord. Connectivity changes after SCI may serve as biomarkers to predict functional recovery following an SCI and guide future therapy.

Minimally invasive transforaminal lumbar interbody fusion with expandable versus static interbody devices: radiographic assessment of sagittal segmental and pelvic parameters.

OBJECTIVE Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) has been adopted as an alternative technique to hasten recovery and minimize postoperative morbidity. Advances in instrumentation technologies and operative techniques have evolved to maximize patient outcomes as well as radiographic results. The development of expandable interbody devices allows a surgeon to perform MIS-TLIF with minimal tissue disruption. However, sagittal segmental and pelvic radiographic outcomes after MIS-TLIF with expandable interbody devices are not well characterized. The object of this study is to evaluate the radiographic sagittal lumbar segmental and pelvic parameter outcomes of MIS-TLIF performed using an expandable interbody device. METHODS A retrospective review of MIS-TLIFs performed between 2014 and 2016 at a high-volume center was performed. Radiographic measurements were performed on lateral radiographs before and after MIS-TLIF with static or expandable interbody devices. Radiographic measurements included disc height, foraminal height, fused disc angle, lumbar lordosis, pelvic incidence, sacral slope, and pelvic tilt. Mismatch between pelvic incidence and lumbar lordosis were calculated for each radiograph. RESULTS A total of 48 MIS-TLIFs were performed, predominantly at the L4-5 level, in 44 patients. MIS-TLIF with an expandable interbody device led to a greater and more sustained increase in disc height when compared with static interbody devices. Foraminal height increased after MIS-TLIF with expandable but not with static interbody devices. MIS-TLIF with expandable interbody devices increased index-level segmental lordosis more than with static interbody devices. The increase in segmental lordosis was sustained in the patients with expandable interbody devices but not in patients with static interbody devices. For patients with a collapsed disc space, MIS-TLIF with an expandable interbody device provided superior and longer-lasting increases in disc height, foraminal height, and index-level segmental lordosis than in comparison with patients with static interbody devices. Using an expandable interbody device improved the Oswestry Disability Index scores more than using a static interbody device, and both disc height and segmental lordosis were correlated with improved clinical outcome. Lumbar MIS-TLIF with expandable or static interbody devices had no effect on overall lumbar lordosis, pelvic parameters, or pelvic incidence-lumbar lordosis mismatch. CONCLUSIONS Performing MIS-TLIF with an expandable interbody device led to a greater and longer-lasting restoration of disc height, foraminal height, and index-level segmental lordosis than MIS-TLIF with a static interbody device, especially for patients with a collapsed disc space. However, neither technique had any effect on radiographic pelvic parameters.

Electrophysiological Sequelae of Hemispherotomy in Ipsilateral Human Cortex.

Objectives: Hemispheric disconnection has been used as a treatment of medically refractory epilepsy and evolved from anatomic hemispherectomy to functional hemispherectomies to hemispherotomies. The hemispherotomy procedure involves disconnection of an entire hemisphere with limited tissue resection and is reserved for medically-refractory epilepsy due to diffuse hemispheric disease. Although it is thought to be effective by preventing seizures from spreading to the contralateral hemisphere, the electrophysiological effects of a hemispherotomy on the ipsilateral hemisphere remain poorly defined. The objective of this study was to evaluate the effects of hemispherotomy on the electrophysiologic dynamics in peri-stroke and dysplastic cortex. Methods: Intraoperative electrocorticography (ECoG) was recorded from ipsilateral cortex in 5 human subjects with refractory epilepsy before and after hemispherotomy. Power spectral density, mutual information, and phase-amplitude coupling were measured from the ECoG signals. Results: Epilepsy was a result of remote perinatal stroke in three of the subjects. In two of the subjects, seizures were a consequence of dysplastic tissue: one with hemimegalencephaly and the second with Rasmussen's encephalitis. Hemispherotomy reduced broad-band power spectral density in peri-stroke cortex. Meanwhile, hemispherotomy increased power in the low and high frequency bands for dysplastic cortex. Functional connectivity was increased in lower frequency bands in peri-stroke tissue but not affected in dysplastic tissue after hemispherotomy. Finally, hemispherotomy reduced band-specific phase-amplitude coupling in peristroke cortex but not dysplastic cortex. Significance: Disconnecting deep subcortical connections to peri-stroke cortex via a hemispherotomy attenuates power of oscillations and impairs the transfer of information from large-scale distributed brain networks to the local cortex. Hence, hemispherotomy reduces heterogeneity between neighboring cortex while impairing phase-amplitude coupling. In contrast, dysfunctional networks in dysplastic cortex lack the normal connectivity with distant networks. Therefore hemispherotomy does not produce the same effects.

MRI-Guided Interstitial Laser Ablation for Intracranial Lesions: A Large Single-Institution Experience of 133 Cases.

BACKGROUND: Managing difficult-to-access lesions or surgically accessible lesions in fragile patients is a central problem in neurosurgery. MRI-guided interstitial laser ablation (ILA) is a minimally invasive option that may provide a safe means of treating these challenging patients. OBJECTIVE: We aim to (1) evaluate safety, efficacy, and preliminary outcomes within a diverse and large series of ILA treatments; and (2) report technical details and operative trends that proved useful over time in the authors' experience and that may be of use to neurosurgeons who perform ILA. METHODS: A retrospective evaluation of ILA patients was performed in terms of demographics, surgical techniques, and clinical outcomes. RESULTS: A total of 133 intracranial lesions in 120 patients were treated with ILA, including glioblastomas (GBM), other gliomas, metastases, epilepsy foci, and radionecrosis. The rate of complications/unexpected readmission was 6.0%, and the mortality rate was 2.2%. With high-grade tumors, tumor volumes >3 cm in diameter trended toward a higher rate of complication (p = 0.056). Median progression-free survival (PFS) and overall survival (OS) for recurrent GBM were 7.4 and 11.6 months, respectively. As a frontline treatment for newly diagnosed GBM, median PFS and OS were 5.9 and 11.4 months, respectively. For metastases, median PFS was not yet reached, and OS was 17.2 months. CONCLUSION: Our series suggests that ILA is a safe and efficacious treatment for a variety of intracranial pathologies, can be tailored to treat difficult-to-access lesions, and may offer a novel alternative to open craniotomy in properly selected patients.

Influence of White and Gray Matter Connections on Endogenous Human Cortical Oscillations.

Brain oscillations reflect changes in electrical potentials summated across neuronal populations. Low- and high-frequency rhythms have different modulation patterns. Slower rhythms are spatially broad, while faster rhythms are more local. From this observation, we hypothesized that low- and high-frequency oscillations reflect white- and gray-matter communications, respectively, and synchronization between low-frequency phase with high-frequency amplitude represents a mechanism enabling distributed brain-networks to coordinate local processing. Testing this common understanding, we selectively disrupted white or gray matter connections to human cortex while recording surface field potentials. Counter to our original hypotheses, we found that cortex consists of independent oscillatory-units (IOUs) that maintain their own complex endogenous rhythm structure. IOUs are differentially modulated by white and gray matter connections. White-matter connections maintain topographical anatomic heterogeneity (i.e., separable processing in cortical space) and gray-matter connections segregate cortical synchronization patterns (i.e., separable temporal processing through phase-power coupling). Modulation of distinct oscillatory modules enables the functional diversity necessary for complex processing in the human brain.

Interpedicular height as a predictor of radicular pain in adult degenerative scoliosis.

BACKGROUND CONTEXT: Spine surgeons must correlate clinical presentation with radiographic findings in a patient-tailored approach. Despite the prevalence of adult degenerative scoliosis (ADS), there are few radiographic markers to predict the presence of radiculopathy. Emerging data suggest that spondylolisthesis, obliquity, foraminal stenosis, and curve concavity may be associated with radiculopathy in ADS. PURPOSE: The purpose of this study was to determine if radicular pain in ADS is associated with reduced interpedicular heights (IPHs) as measured on routine radiographs. STUDY DESIGN/SETTING: This is a retrospective case-controlled study. PATIENT SAMPLE: The authors carried out a retrospective chart review at a tertiary care referral center that included ADS patients referred to scoliosis surgeons between 2012 and 2014. Inclusion criteria included patients with ADS and no prior thoracolumbar surgery. Data were collected from initial spine surgeon clinic notes and radiographs. OUTCOME MEASURES: Clinical outcome data included presence, side(s), and level(s) of radicular pain; presence of motor deficits; and presence of sensory deficits. METHODS: Variables included age, gender, Scoliosis Research Society-30 (SRS-30) and Oswestry Disability Index (ODI) questionnaire data, and radiographic measurements. Radiographic measurements included Cobb angles and L1 to S1 IPHs on upright and supine radiographs. Associations between variables and outcome measures were assessed with univariate and multivariate statistical analyses. Authors have no conflicts of interests relevant to this study. RESULTS: A total of 200 patients with an average age of 51 years met the inclusion criteria. Sixty of the 200 patients presented with radicular pain. Older age was associated with radicular pain, weakness, and sensory deficits. Patients who were 55 years or older were approximately eight times more likely to have radicular pain (odds ratio [OR]=7.96, 95% confidence interval [CI]: 3.73, 17.0; p<.001), five times more likely to have motor deficit (OR=5, 95% CI: 2.55, 9.79; p<.001), and five times more likely to have sensory deficit (OR=5.2, 95% CI: 2.65, 10.2; p<.001) than those younger than 55. More caudally located nerve roots are more likely to develop radicular pain (p<.001). Motor deficits were associated with worse SRS-30 functional (p=.02) and ODI scores (p=.005), but radicular pain and sensory deficits were not associated with lower SRS-30 or ODI scores. Ipsilateral and same-level radicular pain were associated with reduced IPH on supine radiographs (p=.002 and p=.0002, respectively). Finally, reduced IPH on upright radiographs was associated with side- and level-specific radicular pain (p=.04). CONCLUSIONS: Radicular pain in ADS patients is associated with reduced IPHs and older age. Measuring IPHs on routine radiographs may be helpful in associating clinical radiculopathy with radiographic measures to guide patient management and surgical planning.

Transfer of the brachialis to the anterior interosseous nerve as a treatment strategy for cervical spinal cord injury: technical note.

Study Design Technical report. Objective To provide a technical description of the transfer of the brachialis to the anterior interosseous nerve (AIN) for the treatment of tetraplegia after a cervical spinal cord injury (SCI). Methods In this technical report, the authors present a case illustration of an ideal surgical candidate for a brachialis-to-AIN transfer: a 21-year-old patient with a complete C7 spinal cord injury and failure of any hand motor recovery. The authors provide detailed description including images and video showing how to perform the brachialis-to-AIN transfer. Results The brachialis nerve and AIN fascicles can be successfully isolated using visual inspection and motor mapping. Then, careful dissection and microsurgical coaptation can be used for a successful anterior interosseous reinnervation. Conclusion The nerve transfer techniques for reinnervation have been described predominantly for the treatment of brachial plexus injuries. The majority of the nerve transfer techniques have focused on the upper brachial plexus or distal nerves of the lower brachial plexus. More recently, nerve transfers have reemerged as a potential reinnervation strategy for select patients with cervical SCI. The brachialis-to-AIN transfer technique offers a potential means for restoration of intrinsic hand function in patients with SCI.

An evidence-based treatment algorithm for the management of WHO Grade II and III meningiomas.

The management of WHO Grade II "atypical" meningiomas (AMs) and Grade III "malignant" meningiomas (MMs) remains controversial and under-investigated in prospective studies. The roles of surgery, radiation therapy, radiosurgery, and chemotherapy have been incompletely delineated. This has left physicians to decipher how they should treat patients on a case-by-case basis. In this study, the authors review the English-language literature on the management and clinical outcomes associated with AMs and MMs diagnosed using the WHO 2000/2007 grading criteria. Twenty-two studies for AMs and 7 studies for MMs were examined in detail. The authors examined clinical decision points using the literature and concepts from evidence-based medicine. Acknowledging the retrospective nature of the studies concerning AM and MM, the authors did find evidence for the following clinical strategies: 1) maximal safe resection of AM and MM; 2) active surveillance after gross-total resection of AM; 3) adjuvant radiation therapy after subtotal resection of AM, especially in the absence of putative radioresistant features; and 4) adjuvant radiation therapy after resection of MM.