Naif M. Alotaibi

Cerebral vasospasm following tumor resection

Objective To perform a systematic review of the literature of cases of vasospasm following tumor resection and to discuss possible etiologies, diagnosis and management of this complication. Methods A literature search was performed using relevant search key words to identify cases of ‘cerebral vasospasm’ as a complication following tumor resection. Articles were identified by searching MEDLINE and PubMed databases. Relevant cross references were added by manually searching the references of all retrieved articles. Results There were a total of 56 patients in our initial search but only 40 cases matched our inclusion criteria. Pituitary tumors and sellar area were the most common pathologies and location associated with this complication. Average time interval to development of symptomatic vasospasm was 8 days and mortality was high (30%). The most common encountered causative factors were vascular factors (vessel encasement, displacement and narrowing) and presence of blood in the basal cisterns in postoperative scans. Conclusions ‘Cerebral vasospasm’ after tumor resection is a rare but challenging complication with very high morbidity and mortality in reported cases. Vasospasm following brain tumor surgery shares some of the same clinical variables (time interval, causative factors, morbidity and death rates) of vasospasm after aneurysmal subarachnoid hemorrhage. A high index of suspicion is required for early diagnosis and prompt management which are key elements of final outcome.

The Spectrum of Altmetrics in Neurosurgery: The Top 100 “Trending” Articles in Neurosurgical Journals

OBJECTIVE Social media are increasingly used for the dissemination of scientific publications by most medical journals. The role of social media in increasing awareness of published works in neurosurgery has not been previously explored. Here, we present a qualitative analysis of the highest trending works in neurosurgery along with a correlation analysis with their social media metrics. METHODS We performed a comprehensive search for neurosurgical publications using the Altmetric database. The Altmetric database provides a weighted total score of all online mentions for an article received on Facebook, Twitter, blogs, and mainstream media sources. Our search was limited to articles published within the social media era (January 2010-January 2017). Descriptive and correlational statistics were performed for all articles. The top 100 articles in altmetrics were selected for qualitative analysis. RESULTS A total of 5794 articles were included in this study. The average Altmetric score in neurosurgical articles was 4.7 (standard deviation ±22.4). Journals with a social media account had significantly higher Altmetric scores for their articles compared with those without an account (P < 0.0001). The number of tweets and online mentions in news outlets had the strongest correlation values with Altmetric scores. The top 100 articles in altmetrics belonged primarily to the Journal of Neurosurgery (33%) followed by Neurosurgery (29%). CONCLUSIONS This is the first study that details the spectrum of Altmetric scores among neurosurgical journals. Social media presence for journals is important for greater outreach and engagement. Prediction of traditional citation using altmetrics data requires a future prospective study.

Augmented Reality in Neurosurgery: A Review of Current Concepts and Emerging Applications

Augmented reality (AR) superimposes computer-generated virtual objects onto the users view of the real world. Among medical disciplines, neurosurgery has long been at the forefront of image-guided surgery, and it continues to push the frontiers of AR technology in the operating room. In this systematic review, we explore the history of AR in neurosurgery and examine the literature on current neurosurgical applications of AR. Significant challenges to surgical AR exist, including compounded sources of registration error, impaired depth perception, visual and tactile temporal asynchrony, and operator inattentional blindness. Nevertheless, the ability to accurately display multiple three-dimensional datasets congruently over the area where they are most useful, coupled with future advances in imaging, registration, display technology, and robotic actuation, portend a promising role for AR in the neurosurgical operating room.

Spinal intraoperative three-dimensional navigation: correlation between clinical and absolute engineering accuracy

BACKGROUND CONTEXT Spinal intraoperative computer-assisted navigation (CAN) may guide pedicle screw placement. Computer-assisted navigation techniques have been reported to reduce pedicle screw breach rates across all spinal levels. However, definitions of screw breach vary widely across studies, if reported at all. The absolute quantitative error of spinal navigation systems is theoretically a more precise and generalizable metric of navigation accuracy. It has also been computed variably and reported in less than a quarter of clinical studies of CAN-guided pedicle screw accuracy. PURPOSE This study aimed to characterize the correlation between clinical pedicle screw accuracy, based on postoperative imaging, and absolute quantitative navigation accuracy. DESIGN/SETTING This is a retrospective review of a prospectively collected cohort. PATIENT SAMPLE We recruited 30 patients undergoing first-time posterior cervical-thoracic-lumbar-sacral instrumented fusion±decompression, guided by intraoperative three-dimensional CAN. OUTCOME MEASURES Clinical or radiographic screw accuracy (Heary and 2 mm classifications) and absolute quantitative navigation accuracy (translational and angular error in axial and sagittal planes). METHODS We reviewed a prospectively collected series of 209 pedicle screws placed with CAN guidance. Each screw was graded clinically by multiple independent raters using the Heary and 2 mm classifications. Clinical grades were dichotomized per convention. The absolute accuracy of each screw was quantified by the translational and angular error in each of the axial and sagittal planes. RESULTS Acceptable screw accuracy was achieved for significantly fewer screws based on 2 mm grade versus Heary grade (92.6% vs. 95.1%, p=.036), particularly in the lumbar spine. Inter-rater agreement was good for the Heary classification and moderate for the 2 mm grade, significantly greater among radiologists than surgeon raters. Mean absolute translational-angular accuracies were 1.75 mm-3.13° and 1.20 mm-3.64° in the axial and sagittal planes, respectively. There was no correlation between clinical and absolute navigation accuracy. CONCLUSIONS Radiographic classifications of pedicle screw accuracy vary in sensitivity across spinal levels, as well as in inter-rater reliability. Correlation between clinical screw grade and absolute navigation accuracy is poor, as surgeons appear to compensate for navigation registration error. Future studies of navigation accuracy should report absolute translational and angular errors. Clinical screw grades based on postoperative imaging may be more reliable if performed in multiple by radiologist raters.

Dissociation of Early and Delayed Cerebral Infarction After Aneurysmal Subarachnoid Hemorrhage.

Background and Purpose— Cerebral infarction after aneurysmal subarachnoid hemorrhage is a significant cause of substantial morbidity and mortality. Because early and delayed cerebral infarction after aneurysmal subarachnoid hemorrhage may be mediated by different processes, we evaluated whether aneurysm-securing methods contributed to infarcts and whether long-term outcomes differ between early and delayed infarcts. Methods— A post hoc analysis of the CONSCIOUS-1 study (Clazosentan to Overcome Neurological Ischemia and Infarction Occurring After Subarachnoid Hemorrhage) was performed. Using multivariate logistic regression analysis and propensity matching, independent clinical risk factors associated with infarctions were identified, and the contribution of cerebral infarcts to long-term outcomes was evaluated. Results— Within the cohort of 413 subjects, early infarcts were present in 76 subjects (18%), whereas delayed infarcts occurred in 79 subjects (19%), and 36 subjects (9%) had new infarctions that were present on both early and delayed imaging. Propensity score matching revealed a significantly higher proportion of early infarcts after clipping (odds ratio, 4.62; 95% confidence interval, 1.99–11.57; P=0.00012). Multivariate logistic regressions identified clipping as an independent risk factor for early cerebral infarction (odds ratio, 0.26; 95% confidence interval, 0.15–0.48; P<0.001), and angiographic vasospasm was an independent risk factor for delayed cerebral infarction (odds ratio, 1.79; 95% confidence interval, 1.03–3.13; P=0.039). Early infarcts were a significant independent risk factor for poor long-term outcomes at 3 months (odds ratio, 2.34; 95% confidence interval, 1.18–4.67; P=0.015). Conclusions— Clipping is an independent risk factor for the development of early cerebral infarcts, whereas delayed cerebral infarcts are associated with angiographic vasospasm. Early cerebral infarcts are stronger predictors of worse outcome than delayed infarction. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00111085.

Retraction of Neurosurgical Publications: A Systematic Review

OBJECTIVES Despite the increasing awareness of scientific fraud, no attempt has been made to assess its prevalence in neurosurgery. The aim of our review was to assess the chronologic trend, reasons, research type/design, and country of origin of retracted neurosurgical publications. METHODS Three independent reviewers searched the EMBASE and MEDLINE databases using neurosurgical keywords for retracted articles from 1995 to 2016. Archives of retracted articles (retractionwatch.com) and the independent Web sites of neurosurgical journals were also searched. Data including the journal, impact factor, reason for retraction, country of origin, and citations were extracted. RESULTS A total of 97 studies were included for data extraction. Journal impact factor ranged from 0.57 to 35.03. Most studies (61) were retracted within the last 5 years. The most common reason for retraction was because of a duplicated publication found elsewhere (26), followed closely by plagiarism (22), or presenting fraudulent data (14). Other reasons included scientific errors/mistakes, author misattribution, and compromised peer review. Articles originated from several countries and some were widely cited. CONCLUSIONS Retractions of neurosurgical publications are increasing significantly, mostly because of issues of academic integrity, including duplicate publishing and plagiarism. Implementation of more transparent data-sharing repositories and thorough screening of data before manuscript submission, as well as additional educational programs for new researchers, may help mitigate these issues in the future.

Outcome Evaluation of Acute Ischemic Stroke Patients Treated with Endovascular Thrombectomy: A Single-Institution Experience in the Era of Randomized Controlled Trials

BACKGROUND Endovascular thrombectomy is an effective procedure to treat selected ischemic strokes, as shown in recent randomized controlled trials (RCTs). The generalizability of these trial data to real-world settings, however, is unknown. The aim of this study was to examine our single-center experience with endovascular thrombectomy for acute ischemic strokes and perform a comparative outcome analysis to the most recent RCTs. METHODS We performed a 5-year retrospective analysis, from April 2011 to March 2016, on 66 consecutive patients with acute ischemic stroke who received endovascular thrombectomy at our institution. The Alberta Stroke Program Early CT Score (ASPECTS) and the National Institutes of Health Stroke Scale were used to assess preoperative status. Our primary outcomes were the modified Rankin Score (mRS) at 90 days and recanalization grade measured by the 6-point thrombolysis in cerebral infarction (TICI) grading system. RESULTS Sixty-six patients received endovascular treatment during the study period. Among the patients examined, 35 (53%) had a favorable outcome (mRS 0-2 at 90 days), 23 (35%) a poor outcome (mRS 3-5), and 8 (12%) died. Successful recanalization (TICI score 3-5) was achieved in 68% of cases. In univariate analysis, patients with good outcome at 90 days had significantly greater ASPECTS, lower National Institutes of Health Stroke Scale, and higher TICI scores. In a multiple logistic regression model, higher ASPECTS and TICI scores were significantly and independently associated with favorable outcome. CONCLUSIONS Excellent outcomes, as demonstrated by the recent RCTs, can be achieved in clinical practice and reproduced in dedicated tertiary centers.

Acquired Chiari Malformation and Syringomyelia Secondary to Space-Occupying Lesions: A Systematic Review.

BACKGROUND Acquired Chiari malformations (ACM) and associated syringomyelia secondary to space-occupying lesions can cause neurologic deficits independent of or in combination with the offending mass. Although type I Chiari malformations are traditionally treated with posterior fossa decompression, optimal surgical management of ACM and associated syringomyelia remains unclear. The purpose of this study is to review the current literature surrounding the management of ACM. METHODS A systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Using the relevant keywords, articles were identified through multiple databases from inception to April 2016. Our primary outcome was postoperative resolution of tonsillar herniation, syringomyelia, and clinical symptoms and signs. RESULTS Thirty studies (27 case reports and 3 case series), encompassing 44 patients, were included in the review. Meningiomas (36%) and arachnoid cysts (32%) were the lesions most commonly associated with ACM. Offending lesions were usually large (85%) and almost all were found in the posterior fossa (89%). Syringomyelia was present in 82% of cases. Overall, all but 1 patient had improvement or resolution of their syringomyelia after surgery and none required a syrinx shunt. Rates of tonsillar ascent, syrinx resolution, and neurologic recovery were similar in patients who underwent lesion removal alone versus those who underwent posterior fossa decompression and lesion removal. CONCLUSIONS Space-occupying lesions in the posterior fossa are a rare cause of ACM and syringomyelia. Surgical management of the underlying lesion improves ACM and associated syringomyelia without the need for syrinx shunting.

Effects of decompressive craniectomy on functional outcomes and death in poor-grade aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis

OBJECTIVE Patients with poor-grade aneurysmal subarachnoid hemorrhage (aSAH) (World Federation of Neurosurgical Societies Grade IV or V) are often considered for decompressive craniectomy (DC) as a rescue therapy for refractory intracranial hypertension. The authors performed a systematic review and meta-analysis to assess the impact of DC on functional outcome and death in patients after poor-grade aSAH. METHODS A systematic review and meta-analysis were performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Articles were identified through the Ovid Medline, Embase, Web of Science, and Cochrane Library databases from inception to October 2015. Only studies dedicated to patients with poor-grade aSAH were included. Primary outcomes were death and functional outcome assessed at any time period. Patients were grouped as having a favorable outcome (modified Rankin Scale [mRS] Scores 1-3, Glasgow Outcome Scale [GOS] Scores 4 and 5, extended Glasgow Outcome Scale [GOSE] Scores 5-8) or unfavorable outcome (mRS Scores 4-6, GOS Scores 1-3, GOSE Scores 1-4). Pooled estimates of event rates and odds ratios with 95% confidence intervals were calculated using the random-effects model. RESULTS Fifteen studies encompassing 407 patients were included in the meta-analysis (all observational cohorts). The pooled event rate for poor outcome across all studies was 61.2% (95% CI 52%-69%) and for death was 27.8% (95% CI 21%-35%) at a median of 12 months after aSAH. Primary (or early) DC resulted in a lower overall event rate for unfavorable outcome than secondary (or delayed) DC (47.5% [95% CI 31%-64%] vs 74.4% [95% CI 43%-91%], respectively). Among studies with comparison groups, there was a trend toward a reduced mortality rate 1-3 months after discharge among patients who did not undergo DC (OR 0.58 [95% CI 0.27-1.25]; p = 0.168). However, this trend was not sustained at the 1-year follow-up (OR 1.09 [95% CI 0.55-2.13]; p = 0.79). CONCLUSIONS Results of this study summarize the best evidence available in the literature for DC in patients with poor-grade aSAH. DC is associated with high rates of unfavorable outcome and death. Because of the lack of robust control groups in a majority of the studies, the effect of DC on functional outcomes versus that of other interventions for refractory intracranial hypertension is still unknown. A randomized trial is needed.

Chronic hypertrophic nonunion of the Type II odontoid fracture causing cervical myelopathy: Case report and review of literature

Background: Complications of nonunited Type II odontoid fractures can range from neck pain to progressive neurological deficit from cervical myelopathy. Rarely, the hypertrophic nonunion requires both anterior transoral decompression and posterior decompression with instrumented fusion. We present a case and review literature around this entity. Case Description: A 68-year-old female presented with rapidly progressive cervical myelopathy (from normal to moderate myelopathy modified Japanese Orthopedic Association [mJOA] 13) over 3 months. Her history was positive for a Type II odontoid fracture managed conservatively and lost to follow-up for 25 years. Spinal imaging studies revealed hypertrophic nonunion and craniocervical kyphotic deformity with significant subaxial stenosis and segmental kyphosis. The patient underwent anterior transoral decompression, followed by posterior occipitothoracic decompression and instrumented fusion. At follow-up, the cervical myelopathy has improved to near normalcy (mJOA 17) with no evidence or implant-related complication. Conclusion: Rarely, nonunion of Type II odontoid fractures may be hypertrophic where both instability and compression cause neurological morbidity. Such cases require anterior transoral decompression, posterior cervical decompression, and instrumented fusions.