Pseudarthrosis rate following anterior cervical discectomy with fusion using an allograft cellular bone matrix: a multi-institutional analysis.

OBJECTIVE: The use of osteobiologics, engineered materials designed to promote bone healing by enhancing bone growth, is becoming increasingly common for spinal fusion procedures, but the efficacy of some of these products is unclear. The authors performed a retrospective, multi-institutional study to investigate the clinical and radiographic characteristics of patients undergoing single-level anterior cervical discectomy with fusion performed using the osteobiologic agent Osteocel, an allograft mesenchymal stem cell matrix. METHODS: The medical records across 3 medical centers and 12 spine surgeons were retrospectively queried for patients undergoing single-level anterior cervical discectomy and fusion (ACDF) with the use of Osteocel. Pseudarthrosis was determined based on CT or radiographic imaging of the cervical spine. Patients were determined to have radiographic pseudarthrosis if they met any of the following criteria: 1) lack of bridging bone on CT obtained > 300 days postoperatively, 2) evidence of instrumentation failure, or 3) motion across the index level as seen on flexion-extension cervical spine radiographs. Univariate and multivariate analyses were then performed to identify independent preoperative or perioperative predictors of pseudarthrosis in this population. RESULTS: A total of 326 patients met the inclusion criteria; 43 (13.2%) patients met criteria for pseudarthrosis, of whom 15 (34.9%) underwent revision surgery. There were no significant differences between patients with and those without pseudarthrosis, respectively, for patient age (54.1 vs 53.8 years), sex (34.9% vs 47.4% male), race, prior cervical spine surgery (37.2% vs 33.6%), tobacco abuse (16.3% vs 14.5%), chronic kidney disease (2.3% vs 2.8%), and diabetes (18.6% vs 14.5%) (p > 0.05). Presence of osteopenia or osteoporosis (16.3% vs 3.5%) was associated with pseudarthrosis (p < 0.001). Implant type was also significantly associated with pseudarthrosis, with a 16.4% rate of pseudarthrosis for patients with polyetherethereketone (PEEK) implants versus 8.4% for patients with allograft implants (p = 0.04). Average lengths of follow-up were 27.6 and 23.8 months for patients with and those without pseudarthrosis, respectively. Multivariate analysis demonstrated osteopenia or osteoporosis (OR 4.97, 95% CI 1.51-16.4, p < 0.01) and usage of PEEK implant (OR 2.24, 95% CI 1.04-4.83, p = 0.04) as independent predictors of pseudarthrosis. CONCLUSIONS: In patients who underwent single-level ACDF, rates of pseudarthrosis associated with the use of the osteobiologic agent Osteocel are higher than the literature-reported rates associated with the use of alternative osteobiologics. This is especially true when Osteocel is combined with a PEEK implant.

Computer-Assisted Instrument Navigation Versus Conventional C-Arm Fluoroscopy for Surgical Instrumentation: Accuracy, Radiation Time, and Radiation Exposure.

OBJECTIVE. Compared with open procedures, minimally invasive surgical procedures are associated with increased radiation exposure and long-term health risks. Ultralow radiation imaging coupled with image enhancement and instrument tracking (ULRI-IE/IT) is a new image modifier that allows a computer to show real-time movement of an instrument as it is adjusted, mimicking live fluoroscopy but without continuous radiation production. The purpose of this study was to determine the accuracy and radiation output of ULRI-IE/IT compared with unassisted conventional fluoroscopy in a variety of surgical procedures. MATERIALS AND METHODS. Physicians of various specialties were asked to identify the ideal location for instrumentation in various spinal, orthopedic, pain, and physiatric procedures and then place an instrument in this location in a cadaver both with and without ULRI-IE/IT assistance. Whether ULRI-IE/IT was used was randomly assigned to reduce the impact of learning. Radiation exposure, time to place the instrument, and the number of images required to achieve accurate positioning were recorded for each procedure. These were compared for unassisted and ULRI-IE/IT-assisted fluoroscopy to determine the utility of ULRI-IE/IT in minimally invasive instrumentation. RESULTS. Twenty-three trials of nine procedures by five physicians were completed both with and without assistance of ULRI-IE/IT. The procedures ranged from percutaneous pedicle screw insertion to foramen ovale ablation. Total time to localize the instrument for all 23 cases was 31.2% longer without assistance. Use of ULRI-IE/IT reduced the total number of images per case by 74.8% and radiation exposure by 91.8%. With ULRI-IE/IT, physicians were able to successfully place the instrument in the correct location on the first attempt in 82.6% of trials and in the second attempt in all trials versus a mean of 4.65 images needed for unassisted fluoroscopy. CONCLUSION. Use of ULRI-IE/IT can dramatically reduce radiation output and the number of images acquired and time required to perform fluoroscopic procedures.

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.

Endovascular Thrombectomy for Anterior Circulation Stroke: Systematic Review and Meta-Analysis.

BACKGROUND AND PURPOSE: Stroke affects ≈700,000 patients annually. Recent randomized controlled trials comparing endovascular thrombectomy (ET) with medical therapy, including intravenous thrombolysis (IVT) with tissue-type plasminogen activator, have shown effectiveness of ET for some stroke patients. The study objective is to evaluate the effect of ET on good outcome in stroke patients. METHODS: We searched PubMed, Embase, Web of Science, SCOPUS, ClinicalTrials.gov, and Cochrane databases to identify original research publications between 1996 and 2015 that (1) reported clinical outcomes in patients for stroke at 90 days with the modified Rankin Scale; (2) included at least 10 patients per group; (3) compared outcome with a control arm, and (4) included anterior circulation strokes in each arm. Two authors reviewed articles for inclusion independently. RESULTS: Nine of 23 809 studies met inclusion criteria. In primary analysis, ET was associated with increased odds for good outcome (odds ratio [OR], 1.75; 95% confidence interval [CI], 1.20-2.54). In secondary analysis, younger patients (OR, 1.85; 95% CI, 1.50-2.28), older patients (OR, 1.93; 95% CI, 1.10-3.37), patients receiving intravenous thrombolysis (OR, 1.83; 95% CI, 1.46-2.31), patients with worse strokes (OR, 2.23; 95% CI, 1.56-3.18), and patients with more moderate strokes (OR, 1.72; 95% CI, 1.36-2.18) had increased odds for good outcome. Symptomatic intracranial hemorrhage and mortality were similar between ET and control patients. No evidence of publication bias was seen. CONCLUSIONS: ET improves good outcomes after anterior circulation stroke. ET should be strongly considered for all patients presenting within 6 hours of onset with a stroke affecting a proximal, anterior circulation vessel without a contraindication to ET.

Comparison of posterior fossa decompression with or without duraplasty in children with Type I Chiari malformation.

PURPOSE: Chiari malformation type I (CM1) is a common and often debilitating neurosurgical disease. Whether to treat CM1 patients with a traditional posterior fossa decompression with duraplasty (PFDD) or a less invasive extradural decompression (PFDO) is controversial. The purpose of this study was to compare clinical outcome and syrinx resolution between the two procedures. METHODS: We retrospectively reviewed the records of 36 patients treated with PFDD and 29 patients with PFDO between 2003 and 2011. We compared baseline demographic, clinical, and radiographic characteristics. The primary clinical outcome was the Chicago Chiari Outcome Scale (CCOS). The primary radiographic outcome was qualitative syrinx improvement or resolution. RESULTS: At baseline, age and sex distributions, radiographic characteristics, and presenting symptoms were similar in patients undergoing PFDD and PFDO. Patients undergoing PFDO had shorter surgical time (1.5 vs. 2.8 h; p < 0.001) and length of hospital stay (2.1 days compared to 3.3 days; p < 0.001). Cerebrospinal fluid-related complications were more common in patients receiving PFDD (7/36) than PFDO (0/29) (p = 0.014). Clinical improvement, defined by the mean CCOS score, was comparable in patients receiving PFDO (14.7) and PFDD (14.6) (p = 0.70). Among patients with postoperative syrinx imaging, 10/13 in the PFDD group improved or resolved, compared to 8/8 in the PFDO group (p = 0.26). CONCLUSIONS: Extradural decompression for CM1 produces comparable rates of clinical and radiographic improvement as the more invasive decompression with duraplasty. Given the increased morbidity and resource utilization associated with PFDD, PFDO should be considered an attractive first-line option for most CM1 patients.

Delayed synostoses of uninvolved sutures after surgical treatment of nonsyndromic craniosynostosis.

BACKGROUND: Craniosynostosis causes significant cranial deformity in the pediatric population. Open and endoscopic-assisted surgeries have led to increasingly successful management of this condition. Following surgical reconstruction, subsequent development of postnatal synostosis of previously patent sutures have been described and noted to be most frequently associated with multisuture synostosis patients with syndromic diagnoses. Very rarely, postsurgical new sutural fusion has been identified in nonsyndromic patients who initially present with isolated single-suture synostosis. The purpose of this study was to evaluate the incidence of new synostosis among patients who had undergone craniosynostosis reconstruction with either the open or endoscopic technique. METHODS: Patients undergoing open and endoscopic surgery for nonsyndromic craniosynostosis were reviewed. Preoperative and postoperative imaging and clinical information were reviewed, and cases showing progressive cranial deformity were identified. RESULTS: Three (2.1%) of 145 patients undergoing open craniosynostosis surgery and 2 (1.7%) of 121 patients undergoing endoscopic surgery developed delayed fusion of an additional suture during follow-up. This was identified at a median of 16.4 months after initial surgery in the open group and 15.25 months after surgery in the endoscopic group. In patients undergoing open surgery, each patient developed new sagittal synostosis after initial presentation of coronal synostosis in 1 patient and metopic synostosis in 2 patients. In patients undergoing endoscopic surgery, each patient developed new coronal synostosis after sagittal repair. CONCLUSIONS: Management of craniosynostosis has evolved over time with increasing availability of effective and safe treatments. During long-term follow-up, a small number of patients may develop premature closure of a different suture that did not undergo surgical manipulation. In our case, series, we identified 3 patients undergoing open surgery and 2 patients undergoing endoscopic surgery for nonsyndromic, single-suture craniosynostosis. This finding supports the necessity of long-term clinical follow-up and the utility of delayed imaging when clinical suspicion indicates.

Operative time and learning curve between fluoroscopy-based instrument tracking and robot-assisted instrumentation for patients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF).

INTRODUCTION: Instrument-navigation modalities including CT-guided and robot-assisted methods claim both efficacy and accuracy when applied to spine surgery, yet often increase setup and operating times which can translate to increased costs. To see the impact of different technologies on surgical efficiency, we studied the impact of a single surgeon's experience with a multitude of instrument navigational technologies. METHODS: Consecutive patients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) were analyzed. Consecutive cases were done with assistance of a robot (Mazor, Medtronic, Minneapolis, MN), with the assistance of fluoroscopic instrument-tracking (TrackX, North Carolina, USA), or fluoroscopy alone without adjunctive navigation in consecutive blocks of time. The cases done without assistance were used to normalize for number of interbody implants and decompressions performed as well as hardware removal if needed. Age, body mass index (BMI), sex, operative levels, laminectomy, need for hardware removal, and total operative time were recorded. RESULTS: A total of 119 cases (74 conventional, 13 robot-assisted, 32 instrument-tracking) were included in analysis. There were no significant differences in age, sex, or BMI between modalities. Average total operative time for robot-assisted, and instrument-tracking-assisted cases was 175.46 ± 46.86 min 119.63 ± 34.33 min, respectively, for each level (p < 0.05 across each group). After normalization against operative times from similar cases performed with conventional fluoroscopy, robotic-navigation added an average of 42.25 ± 28.35 min while use of instrument-tracking saved an average of 13.88 ± 38.69 min. There was no learning curve seen using robotic navigation, as operative times remained consistently longer than similar cases using conventional fluoroscopy and showed no sign of improvement over time. Cases using instrument-tracking were initially slower but trended downwards through approximately 11 patients, at which point operative times were consistently quicker (R2 = 0.39). None of the assisted cases were abandoned in favor of standard fluoroscopy or required hardware revision. CONCLUSION: Enabling technology can have a significant impact on surgical efficiency. Compared to MIS-TLIFs performed with standard fluoroscopy, those done with robotic-assistance consistently negatively impacted operative times while instrument-tracking was associated with a short learning curve and in the majority of cases studied showed improved operative times.

Stem cells in the treatment of stroke.

Stroke is an often devastating insult resulting in neurological deficit lasting greater than 24 hours. In the United States, stroke is the third leading cause of death. In those who do not succumb, any outcome from total recovery over a period of weeks to months to persistent profound neurological deficits is possible. Present treatment centers on the decision to administer tissue plasminogen activator, subsequent medical stabilization and early intervention with rehabilitation and risk factor management. The advent of stem cell therapy presents an exciting new frontier for research in stroke treatment, with the potential to cause a paradigm shift from symptomatic control and secondary prevention to reconstitution of neural networks and prevention of neuronal cell death after neurologic injury.

Gene- and cell-based approaches for neurodegenerative disease.

Neurodegenerative diseases comprise an important group ofchronic diseases that increase in incidence with rising age. In particular, the two most common neurodegenerative diseases are Alzheimer's disease and Parkinson's disease, both of which will be discussed below. A third, Huntington's disease, occurs infrequently, but has been studied intensely. Each of these diseases shares characteristics which are also generalizeable to other neurodegenerative diseases: accumulation ofproteinaceous substances that leads inexorably to selective neuronal death and decline in neural function. Treatments for these diseases have historically focused on symptomatic relief, but recent advances in molecular research have identified more specific targets. Additionally, stem cell therapy, immunotherapy and trophic-factor delivery provide avenues for neuronal protection that may alter the natural progression of these devastating illnesses. Upcoming clinical trials will evaluate treatment strategies and provide hope that translational research will decrease the onset of debilitating disability associated with neurodegenerative disease.

Effect of Instrument Navigation on C-arm Radiation and Time during Spinal Procedures: A Clinical Evaluation.

INTRODUCTION: As minimally invasive spine surgery gains popularity, a focused effort must be made to reduce intraoperative radiation exposure to levels as low as reasonably achievable. Here, we demonstrate the clinical efficacy of a novel technology to aid in instrument navigation that aims to reduce intraoperative radiation exposure, number of fluoroscopic images, and time required to perform the most radiation intensive portions of a multitude of spinal procedures. METHODS: An internally randomized controlled study was performed over a 1-month period in order to clinically evaluate the effect of the C-arm assisted instrument tracking system, TrackX, on surgeon workflow, time, and radiation emitted. Three surgeons performed multiple spinal procedures on a total of 10 study patients and an additional 3 control patients. The surgeries encompassed minimally invasive spinal techniques and spanned extreme lateral interbody fusion, oblique lumbar interbody fusion, transforaminal lumbar interbody fusion along with percutaneous iliac screw placement, hardware removal, and kyphoplasty. The tasks studied included skin marking, first dilator insertion, localization for hardware placement and hardware removal. RESULTS: Overall radiation reduction was 83% (P < .0001). Overall reduction in x-rays taken was 78% (P < .0001). Overall time reduction was 81% (P = .0003). Statistical significance held for each surgeon studied and for nearly every procedure type. In these 10 study procedures, over 2 hours of overall operating room time was saved, all while requiring negligible set up time and no system calibration or supplementary x-rays to be taken. There were no adverse outcomes for any study patient, and there was no case where TrackX was not able to successfully complete a given portion of a procedure. CONCLUSIONS: TrackX instrument navigation is a clinically efficacious and accurate instrument tracking modality. This is the first instrument navigational technology that reduces radiation exposure and images required to complete a procedure while decreasing operative time. TrackX thus allows increased surgical efficiency while increasing operative efficiency and improving intraoperative safety. LEVEL OF EVIDENCE: 2.

A Smartphone App With a Digital Care Pathway for Patients Undergoing Spine Surgery: Development and Feasibility Study.

BACKGROUND: There is a great unmet clinical need to provide patients undergoing spinal surgery and their caregivers with ongoing, high-quality care before and after surgery in an efficiency-focused health care environment. OBJECTIVE: The objective of this study is to design, develop, and evaluate the acceptability and feasibility of a novel planning-, outcomes-, and analytics-based smartphone app called ManageMySurgery (MMS) in patients undergoing elective spine surgery (MMS-Spine). METHODS: The development process of the MMS app was conducted over 2 sequential stages: (1) an evidence-based intervention design with refinement from surgeon and patient feedback and (2) feasibility testing in a clinical pilot study. We developed a novel, mobile-based, Health Insurance Portability and Accountability Act-compliant platform for interventional and surgical procedures. It is a patient-centric mobile health app that streamlines patients' interactions with their care team. MMS divides the patient journey into phases, making it feasible to provide customized care pathways that meet patients' unique needs. Patient-reported outcomes are easily collected and conform to the National Institutes of Health Patient-Reported Outcomes Measurement Information System (PROMIS) standard. RESULTS: We tested the feasibility of the MMS-Spine app with patients undergoing elective spine surgery at a large academic health system. A total of 47 patients undergoing elective spine surgery (26 cervical spine and 21 lumbar spine surgeries) downloaded and used MMS-Spine to navigate their surgical journey, quantify their baseline characteristics and postoperative outcomes, and provide feedback on the utility of the app in preparing for and recovering from their spinal surgery. The median age was 59.0 (range 33-77) years, 22 of the 47 patients (47%) were women, and 26 patients (55%) had commercial insurance. Of the 47 patients, a total of 33 (70%) logged in on an iOS device, 11 (23%) on an Android device, and 3 (6%) on a computer or tablet. A total of 17 of the 47 patients (36%) added a caregiver, of which 7 (41%) logged in. The median number of sign-ins was 2. A total of 38 of 47 patients (81%) completed their baseline preoperative PROMIS-29 outcomes, and 14 patients (30%) completed at least one PROMIS-29 survey during the postoperative period. Of the 24 patients who completed the MMS survey, 21 (88%) said it was helpful during preparation for their procedure, 16 (67%) said it was helpful during the postoperative period, and 23 (96%) said that they would recommend MMS to a friend or family member. CONCLUSIONS: We used a patient-centered approach based on proven behavior change techniques to develop a comprehensive smartphone app for patients undergoing elective spine surgery. The optimized version of the app is ready for formal testing in a larger randomized clinical study to establish its cost-effectiveness and effect on patients' self-management skills and long-term outcomes.

Balamuthia mandrillaris meningoencephalitis in an immunocompromised patient. Case report.

Balamuthia mandrillaris is a rare but increasingly recognized cause of amebic encephalitis, yet it remains poorly understood. The condition is almost universally fatal, and due to diagnostic difficulty, most cases are identified postmortem. The authors report a case of Balamuthia amebic encephalitis in a patient with combined variable immunodeficiency in which a rare antemortem diagnosis was made via brain biopsy. Despite broad-spectrum antimicrobial therapy, the outcome was fatal. Such presentations are challenging, and definitive diagnosis may require biopsy in consultation with a skilled neuropathologist.

Spinal Fusion for Pediatric Spondylolisthesis: National Trends, Complications, and Short-Term Outcomes.

BACKGROUND: Current surgical management guidelines for pediatric spondylolisthesis (PS) are reliant on data from single-center cohorts. OBJECTIVE: To analyze national trends and predictors of short-term outcomes in spinal fusion surgery for PS by performing a retrospective cross-sectional analysis of the Kids' Inpatient Database (KID). METHODS: The KID (sampled every 3 yr) was queried from 2003 to 2012 to identify all cases (age 5-17) of spinal fusion for PS (n = 2646). We analyzed trends in patient characteristics, surgical management, and short-term outcomes. Both univariate and multivariable analyses were utilized. RESULTS: The 2646 spinal fusions for PS included posterior-only fusions (86.8%, PSF), anterior lumbar interbody fusions (4.8%, ALIF), and combined anterior and posterior fusions (8.4%, APLF) procedures. The utilization of APLF decreased over time (9.9%-6.4%, P = .023), whereas the number of total spinal fusions and the proportion of PSF and ALIF procedures have not changed significantly. Uptrends in Medicaid insured individuals (1.2%-18.9%), recombinant human bone morphogenetic protein-2 insertion (8.8%-16.6%), decompression (34.7%-42.8%), and mean inflation-adjusted hospital costs ($21 855-$32 085) were identified (all P < .001). In multivariable analysis, Medicaid status (odds ratio [OR] = 1.93, P = .004), teaching hospitals (OR = 1.94, P = .01), decompression (OR = 1.78, P = .004), and the APLF procedure (OR = 2.47, P = .001) increased the likelihood of complication occurrence (all P < .001). CONCLUSION: The addition of decompression during fusion and the APLF procedure were associated with more in-hospital complications, though this may have been indicative of greater surgical complexity. The utilization of the APLF procedure has decreased significantly, while costs associated with the treatment of PS have increased over time.

Influence of racial disparities on patient-reported satisfaction and short- and long-term perception of health status after elective lumbar spine surgery.

OBJECTIVE In spine surgery, racial disparities have been shown to impact various aspects of surgical care. Previous studies have associated racial disparities with inferior surgical outcomes, including increased complication and 30-day readmission rates after spine surgery. Recently, patient-reported outcomes (PROs) and satisfaction measures have been proxies for overall quality of care and hospital reimbursements. However, the influence that racial disparities have on short- and long-term PROs and patient satisfaction after spine surgery is relatively unknown. The aim of this study was to investigate the impact of racial disparities on 3- and 12-month PROs and patient satisfaction after elective lumbar spine surgery. METHODS This study was designed as a retrospective analysis of a prospectively maintained database. The medical records of adult (age ≥ 18 years) patients who had undergone elective lumbar spine surgery for spondylolisthesis (grade 1), disc herniation, or stenosis at a major academic institution were included in this study. Patient demographics, comorbidities, postoperative complications, and 30-day readmission rates were collected. Patients had prospectively collected outcome and satisfaction measures. Patient-reported outcome instruments-Oswestry Disability Index (ODI), visual analog scale for back pain (VAS-BP), and VAS for leg pain (VAS-LP)-were completed before surgery and at 3 and 12 months after surgery, as were patient satisfaction measures. RESULTS The authors identified 345 medical records for 53 (15.4%) African American (AA) patients and 292 (84.6%) white patients. Baseline patient demographics and comorbidities were similar between the two cohorts, with AA patients having a greater body mass index (33.1 ± 6.6 vs 30.2 ± 6.4 kg/m2, p = 0.005) and a higher prevalence of diabetes (35.9% vs 16.1%, p = 0.0008). Surgical indications, operative variables, and postoperative variables were similar between the cohorts. Baseline and follow-up PRO measures were worse in the AA cohort, with patients having a greater baseline ODI (p < 0.0001), VAS-BP score (p = 0.0002), and VAS-LP score (p = 0.0007). However, mean changes from baseline to 3- and 12-month PROs were similar between the cohorts for all measures except the 3-month VAS-BP score (p = 0.046). Patient-reported satisfaction measures at 3 and 12 months demonstrated a significantly lower proportion of AA patients stating that surgery met their expectations (3 months: 47.2% vs 65.5%, p = 0.01; 12 months: 35.7% vs 62.7%, p = 0.007). CONCLUSIONS The study data suggest that there is a significant difference in the perception of health, pain, and disability between AA and white patients at baseline and short- and long-term follow-ups, which may influence overall patient satisfaction. Further research is necessary to identify patient-specific factors associated with racial disparities that may be influencing outcomes to adequately measure and assess overall PROs and satisfaction after elective lumbar spine surgery.

Thrombolysis is an Independent Risk Factor for Poor Outcome After Carotid Revascularization.

BACKGROUND: Thrombolysis is the standard of care for acute ischemic stroke patients presenting in the appropriate time window. Studies suggest that the risk of recurrent ischemia is lower if carotid revascularization is performed early after the index event. The safety of early carotid revascularization in this patient population is unclear. OBJECTIVE: To evaluate the safety of carotid revascularization in patients who received thrombolysis for acute ischemic stroke. METHODS: The Nationwide Inpatient Sample database was queried for patients admitted through the emergency room with a primary diagnosis of carotid stenosis and/or occlusion. Each patient was reviewed for administration of thrombolysis, carotid endarterectomy, (CEA) or carotid angioplasty and stenting (CAS). Primary endpoints were intracerebral hemorrhage (ICH), postprocedural stroke (PPS), poor outcome, and in-hospital mortality. Potential risk factors were examined using univariate and multivariate analyses. RESULTS: A total of 310 257 patients were analyzed. Patients who received tissue plasminogen activator (tPA) and underwent either CEA or CAS had a significantly higher risk of developing an ICH or PPS than patients who underwent either CEA or CAS without tPA administration. The increased risk of ICH or PPS in tPA-treated patients who underwent carotid revascularization diminished with time, and became similar to patients who underwent carotid revascularization without tPA administration by 7 d after thrombolysis. Patients who received tPA and underwent CEA or CAS also had higher odds of poor outcome and in-hospital mortality. CONCLUSION: Thrombolysis is a strong risk factor for ICH, PPS, poor outcome, and in-hospital mortality in patients with carotid stenosis/occlusion who undergo carotid revascularization. The increased risk of ICH or PPS due to tPA declines with time after thrombolysis. Delaying carotid revascularization in these patients may therefore be appropriate. This delay, however, will expose these patients to the risk of recurrent stroke. Future studies are needed to determine the relative risks of these 2 adverse events.

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.

Fractional anisotropy to quantify cervical spondylotic myelopathy severity.

BACKGROUND: A number of clinical tools exist for measuring the severity of cervical spondylotic myelopathy (CSM). Several studies have recently described the use of non-invasive imaging biomarkers to assess severity of disease. These imaging markers may provide an additional tool to measure disease progression and represent a surrogate marker of response to therapy. Correlating these imaging biomarkers with clinical quantitative measures is critical for accurate therapeutic stratification and quantification of axonal injury. METHODS: Fourteen patients and seven healthy control subjects were enrolled. Patients were classified as mildly (7) or moderately (7) impaired based on Modified Japanese Orthopedic Association Scale. All patients underwent diffusion tensor imaging (DTI) and diffusion basis spectrum imaging (DBSI) analyses. In addition to standard neurological examination, all participants underwent 30-m Walking Test, 9-hole Peg Test (9HPT), grip strength, key pinch, and vibration sensation thresholds in the index finger and great toe. Differences in assessment scores between controls, mild and moderate CSM patients were correlated with DTI and DBSI derived fractional anisotropy (FA). RESULTS: Clinically, 30-meter walking times were significantly longer in the moderately impaired group than in the control group. Maximum 9HPT times were significantly longer in both the mildly and moderately impaired groups as compared to normal controls. Scores on great toe vibration sensation thresholds were lower in the mildly impaired and moderately impaired groups as compared to controls. We found no clear evidence for any differences in minimum grip strength, minimum key pinch, or index finger vibration sensation thresholds. There were moderately strong associations between DTI and DBSI FA values and 30-meter walking times and 9HPT. CONCLUSIONS: The 30-m Walking Test and 9HPT were both moderately to strongly associated with DTI/DBSI FA values. FA may represent an additional measure to help differentiate and stratify patients with mild or moderate CSM.

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.