James Zhou

Diagnostic accuracy of evoked potentials for functional impairment after contusive spinal cord injury in adult rats

Iatrogenic spinal cord injury (SCI) is a cause of potentially debilitating post-operative neurologic complications. Currently, intra-operative neurophysiological monitoring (IONM) via somatosensory evoked potentials and motor-evoked potentials is used to detect and prevent impending SCI. However, no empirically validated interventions exist to halt the progression of iatrogenic SCI once it is detected. This is in part due to the lack of a suitable translational model that mimics the circumstances surrounding iatrogenic SCI detected via IONM. Here, we evaluate a model of simulated contusive iatrogenic SCI detected via IONM in adult female Sprague-Dawley rats. We show that transient losses of somatosensory evoked potentials responses are 88.24% sensitive (95% confidence interval [CI] 63.53-98.20) and 80% specific (95% CI 51.91-95.43) for significant functional impairment following simulated iatrogenic SCI. Similarly, we show that transient losses in motor-evoked potentials responses are 70.83% sensitive (95% CI 48.91-87.33) and 100% specific (95% CI 62.91-100.00) for significant functional impairment following simulated iatrogenic SCI. These results indicate that our model is a suitable replica of the circumstances surrounding clinical iatrogenic SCI.

The 100 most cited articles in metastatic spine disease

OBJECTIVE Despite the growing neurosurgical literature, a subset of pioneering studies have significantly impacted the field of metastatic spine disease. The purpose of this study was to identify and analyze the 100 most frequently cited articles in the field. METHODS A keyword search using the Thomson Reuters Web of Science was conducted to identify articles relevant to the field of metastatic spine disease. The results were filtered based on title and abstract analysis to identify the 100 most cited articles. Statistical analysis was used to characterize journal frequency, past and current citations, citation distribution over time, and author frequency. RESULTS The total number of citations for the final 100 articles ranged from 74 to 1169. Articles selected for the final list were published between 1940 and 2009. The years in which the greatest numbers of top-100 studies were published were 1990 and 2005, and the greatest number of citations occurred in 2012. The majority of articles were published in the journals Spine (15), Cancer (11), and the Journal of Neurosurgery (9). Forty-four individuals were listed as authors on 2 articles, 9 were listed as authors on 3 articles, and 2 were listed as authors on 4 articles in the top 100 list. The most cited article was the work by Batson (1169 citations) that was published in 1940 and described the role of the vertebral veins in the spread of metastases. The second most cited article was Patchells 2005 study (594 citations) discussing decompressive resection of spinal cord metastases. The third most cited article was the 1978 study by Gilbert that evaluated treatment of epidural spinal cord compression due to metastatic tumor (560 citations). CONCLUSIONS The field of metastatic spine disease has witnessed numerous milestones and so it is increasingly important to recognize studies that have influenced the field. In this bibliographic study the authors identified and analyzed the most influential articles in the field of metastatic spine disease.

Perioperative neurologic complications during spinal fusion surgery: incidence and trends

BACKGROUND CONTEXT Perioperative neurologic complications after spine surgery may increase morbidity and health-care costs related to the procedure. PURPOSE We estimate the national incidence of perioperative neurologic complications following anterior cervical discectomy and fusion (ACDF), posterior cervical fusion, and thoracolumbar fusion procedures using the Nationwide Inpatient Sample (NIS) data from 1999 to 2011. Additionally, we identify risk factors for developing perioperative neurologic complications and the effects of these injuries on quantifiable patient outcomes. STUDY DESIGN A cross-sectional study was carried out. PATIENT SAMPLE All patients included in the NIS databases from 1999 to 2011 comprised the sample. OUTCOME MEASURES The primary outcome evaluated was the incidence of new neurologic deficits following elective spine surgery. Secondary outcomes evaluated include length of hospital stay, total hospital charges, hospital mortality rate, and discharge disposition. METHODS A retrospective analysis of the NIS databases from the years 1999 to 2011 was conducted to identify the proportion of patients who underwent ACDFs, posterior cervical fusions, and thoracolumbar fusions who also developed perioperative neurologic complications. Statistical analyses were also conducted to identify statistically significant differences in demographics and outcomes between patients who did and did not develop perioperative neurologic complications. RESULTS From 1999 to 2011, the total national incidence of perioperative neurologic deficits following elective ACDFs, posterior cervical fusions, and thoracolumbar fusions was 0.82%, which equates to a total of 15,066 patients who experienced these complications. The annual incidence rate of perioperative neurologic deficits has increased 54.41%, from 0.68% in the year 1999 to 1.05% in the year 2011. Additionally, the total number of procedures performed increased from 82,167 in 1999 to 186,353 in the year 2011. Perioperative neurologic deficits were associated with longer lengths of stay (9.68 days vs. 2.59 days; p<.001), higher total charges (

Design and Testing of 2 Novel Scores That Predict Global Sagittal Alignment Utilizing Cervical or Lumbar Plain Radiographs

110,326.23 vs.

Bedside iohexol ventriculography for patients with obstructive colloid cysts: a protocol to identify auto-fenestration of the septum pellucidum

48,695.93; p<.001), and higher in-hospital mortality (2.84% vs. 0.13%; p<.001). CONCLUSIONS The incidence rate of perioperative neurologic deficits associated with elective spine surgery documented in the NIS has increased over the time period from 1999 to 2011. The number of elective spine procedures performed has also increased over the same time period. Finally, outcomes data indicate that occurrence of perioperative neurologic complications is associated with increased rates of morbidity and mortality, as well as increased health-care use and cost. These trends indicate that the perioperative neurologic complications following spine surgery represent a growing problem in todays health-care system; further study is warranted to prevent and treat these complications to improve patient care and reduce health-care use and cost.

100 Most Influential Publications in Scoliosis Surgery

BACKGROUND Global sagittal deformity is an established cause of disability. However, measurements of sagittal alignment are often ignored when patients present with symptoms localizing to the cervical or lumbar spine. OBJECTIVE To develop scoring scales to predict the risk of sagittal malalignment in patients with only cervical or lumbar spine radiographs. METHODS A retrospective review of a prospectively maintained multicenter adult spinal deformity database was performed. Primary outcome (sagittal malalignment) was defined as a C7 plumbline ≥ 50 mm. Two multivariate logistic regressions were performed using patient characteristics and measurements derived from cervical or lumbar radiographs as covariates. Point scores were assigned to age, body mass index (BMI), and lumbar lordosis or T1 slope by rounding their &bgr; coefficients to the nearest integer. RESULTS Nine hundred seventy‐nine patients were included, with 652 randomly assigned to the derivation cohort (used to build the score) and 327 comprising the validation set. Final cervical score for the primary outcome included BMI ≥ 25 (1 point), age ≥ 55 yr (2 points), and T1 slope ≥ 27o (2 points). Final lumbar score for the primary outcome included BMI ≥ 25 (1 point), age ≥ 55 yr (1 point), and lumbar lordosis ≥ 45o (-1 points). High scores for both the cervical and lumbar spine presented with high specificity and positive likelihood ratios of sagittal malalignment. CONCLUSION We developed scoring scales to predict global sagittal malalignment utilizing clinical covariates and cervical or lumbar radiographs. Patients with high scores may prompt imaging with long‐cassette plain films to evaluate for global sagittal imbalance.

Top 50 most-cited articles on craniovertebral junction surgery

OBJECTIVE Patients with hydrocephalus secondary to third ventricular colloid cysts can require bilateral external ventricular drain (EVD) placement while awaiting surgery. However, some patients could develop auto-fenestration of the septum pellucidum (AFSP) and only require 1 EVD. We evaluated our experience with bedside iohexol ventriculography and staged EVD placement for patients with obstructive hydrocephalus. METHODS We retrospectively identified 34 patients who had been treated for third ventricular colloid cysts (2013-2016). The preoperative and postoperative data, including age, sex, colloid cyst size, preoperative hydrocephalus, preoperative EVD placement, preoperative iohexol ventriculography, operative approach, intraoperative findings, and postoperative ventriculoperitoneal shunt requirements, were reviewed. RESULTS Hydrocephalus was found in 23 patients (68%) on initial presentation. Nine patients (26%) had EVDs placed before surgery. Six patients (18%) underwent iohexol ventriculography after insertion of a right-sided EVD. Five patients (15%) demonstrated no evidence of ventricular communication. Four patients (67%) required left-sided EVD placement. One patient (17%) had robust communication between the lateral ventricles after intraventricular iohexol injection, which was managed with a single EVD. AFSP was observed during surgical resection of this patients colloid cyst. One other patient who did not undergo preoperative EVD placement was noted to have AFSP intraoperatively, resulting in 2 of 34 patients (6%) with AFSP in our series. CONCLUSIONS A subset of patients with obstruction at the foramina of Monro can develop AFSP. Iohexol ventriculography after unilateral EVD placement allows clinicians to assess for the presence of AFSP and identify patients who can be treated with a single EVD before surgery.

The 100 most influential publications pertaining to intracranial aneurysms and aneurysmal subarachnoid hemorrhage

Study Design. Bibliometric analysis. Objective. To apply the established technique of citation analysis to identify the 100 most influential articles in scoliosis surgery research published between 1900 and 2015. Summary of Background Data. Previous studies have applied the technique of citation analysis to other areas of study. This is the first article to apply this technique to the field of scoliosis surgery. Methods. A two-step search of the Thomson Reuters Web of Science was conducted to identify all articles relevant to the field of scoliosis surgery. The top 100 articles with the most citations were identified based on analysis of titles and abstracts. Further statistical analysis was conducted to determine whether measures of author reputation and overall publication influence affected the rate at which publications were recognized and incorporated by other researchers in the field. Results. Total citations for the final 100 publications included in the list ranged from 82 to 509. The period for publication ranged from 1954 to 2010. Most studies were published in the journal Spine (n = 63). The most frequently published topics of study were surgical techniques (n = 35) and outcomes (n = 35). Measures of author reputation (number of total studies in the top 100, number of first-author studies in the top 100) were found to have no effect on the rate at which studies were adopted by other researchers (number of years until first citation, and number of years until maximum citations). The number of citations/year a publication received was found to be negatively correlated with the rate at which it was adopted by other researchers, indicating that more influential manuscripts attained more rapid recognition by the scientific community at large. Conclusion. In assembling this publication, we have strived to identify and recognize the 100 most influential articles in scoliosis surgery research from 1900 to 2015. Level of Evidence: N/A

Long-term clinical outcomes following surgical management of cervical spine fractures in elderly patients

Background: Craniovertebral junction is a complex anatomical location posing unique challenges to the surgical management of its pathologies. We aimed to identify the fifty most-cited articles that are dedicated to this field. Methods: A keyword search using the Thomson Reuters Web of Knowledge was conducted to identify articles relevant to the field of craniovertebral junction surgery. The articles were reviewed based on title, abstract, and methods, if necessary, and then ranked based on the total number of citations to identify the fifty most-cited articles. Characteristics of the articles were determined and analyzed. Results: The earliest top-cited article was published in 1948. When stratified by decade, 1990s was the most productive with 16 articles. The most-cited article was by Anderson and Dalonzo on a classification of odontoid fractures. By citation rate, the most-cited article was by Herms and Melcher who described Goels technique of atlantoaxial fixation using C1 lateral mass screws and C2 pedicle screws with rod fixation. Atlantoaxial fixation was the most common topic. The United States, Barrow Neurological Institute, and VH Sonntag were the most represented country, institute, and author, respectively. The significant majority of articles were designed as case series providing level IV evidence. Conclusion: Using citation analysis, we have provided a list of the most-cited articles representing important contributions of various authors from many institutions across the world to the field of craniovertebral junction surgery.