James G. Malcolm

Complications following cranioplasty and relationship to timing: A systematic review and meta-analysis

The optimal timing of cranioplasty after decompressive craniectomy has not been well established. The purpose of this study was to evaluate the relationship between timing of cranioplasty and related complications. A systematic search of MEDLINE, Scopus, and the Cochrane databases was performed using PRISMA guidelines for English-language articles published between 1990 and 2015. Case series, case-control and cohort studies, and clinical trials reporting timing and complication data for cranioplasty after decompressive craniectomy in adults were included. Extracted data included overall complications, infections, reoperations, intracranial hemorrhage, extra-axial fluid collections, hydrocephalus, seizures, and bone resorption for cranioplasty performed within (early) and beyond (late) 90days. Twenty-five of 321 articles met inclusion criteria for a total of 3126 patients (1421 early vs. 1705 late). All were retrospective observational studies. Early cranioplasty had significantly higher odds of hydrocephalus than late cranioplasty (Odds Ratio [OR] 2.38, 95% Confidence Interval [CI] 1.25-4.52, p=0.008). There was no difference in odds of overall complications, infections, reoperations, intracranial hemorrhage, extra-axial fluid collections, seizures, or bone resorption. Subgroup analysis of trauma patients revealed a decreased odds of extra-axial fluid collection (OR 0.30, p=0.02) and an increased odds of hydrocephalus (OR 4.99, p=0.05). Early cranioplasty within 90days after decompressive craniectomy is associated with an increased odds of hydrocephalus than with later cranioplasty, but no difference in odds of developing other complications. Earlier cranioplasty in the trauma population is associated with fewer extra-axial fluid collections.

Early Cranioplasty is Associated with Greater Neurological Improvement: A Systematic Review and Meta-Analysis

BACKGROUND Cranioplasty after decompressive craniectomy is a common neurosurgical procedure, yet the optimal timing of cranioplasty has not been well established. OBJECTIVE To investigate whether the timing of cranioplasty is associated with differences in neurological outcome. METHODS A systematic literature review and meta-analysis was performed using MEDLINE, Scopus, and the Cochrane databases for studies reporting timing and neurological assessment for cranioplasty after decompressive craniectomy. Pre- and postcranioplasty neurological assessments for cranioplasty performed within (early) and beyond (late) 90 d were extracted. The standard mean difference (SMD) was used to normalize all neurological measures. Available data were pooled to compare pre-cranioplasty, postcranioplasty, and change in neurological status between early and late cranioplasty cohorts, and in the overall population. RESULTS Eight retrospective observational studies were included for a total of 528 patients. Studies reported various outcome measures (eg, Barthel Index, Karnofsky Performance Scale, Functional Independence Measure, Glasgow Coma Scale, and Glasgow Outcome Score). Cranioplasty, regardless of timing, was associated with significant neurological improvement (SMD .56, P = .01). Comparing early and late cohorts, there was no difference in precranioplasty neurological baseline; however, postcranioplasty neurological outcome was significantly improved in the early cohort (SMD .58, P = .04) and showed greater magnitude of change (SMD 2.90, P = .02). CONCLUSION Cranioplasty may improve neurological function, and earlier cranioplasty may enhance this effect. Future prospective studies evaluating long-term, comprehensive neurological outcomes will be required to establish the true effect of cranioplasty on neurological outcome.

Effects of Cranioplasty on Cerebral Blood Flow Following Decompressive Craniectomy: A Systematic Review of the Literature.

BACKGROUND Cranioplasty after decompressive craniectomy (DC) is routinely performed for reconstructive purposes and has been recently linked to improved cerebral blood flow (CBF) and neurological function. OBJECTIVE To systematically review all available literature to evaluate the effect of cranioplasty on CBF and neurocognitive recovery. METHODS A PubMed, Google Scholar, and MEDLINE search adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines included studies reporting patients who underwent DC and subsequent cranioplasty in whom cerebral hemodynamics were measured before and after cranioplasty. RESULTS The search yielded 21 articles with a total of 205 patients (range 3-76 years) who underwent DC and subsequent cranioplasty. Two studies enrolled 29 control subjects for a total of 234 subjects. Studies used different imaging modalities, including CT perfusion (n = 10), Xenon-CT (n = 3), single-photon emission CT (n = 2), transcranial Doppler (n = 6), MR perfusion (n = 1), and positron emission tomography (n = 2). Precranioplasty CBF evaluation ranged from 2 days to 6 months; postcranioplasty CBF evaluation ranged from 7 days to 6 months. All studies demonstrated an increase in CBF ipsilateral to the side of the cranioplasty. Nine of 21 studies also reported an increase in CBF on the contralateral side. Neurological function improved in an overwhelming majority of patients after cranioplasty. CONCLUSION This systematic review suggests that cranioplasty improves CBF following DC with a concurrent improvement in neurological function. The causative impact of CBF on neurological function, however, requires further study.

Spinal cord ependymoma: a review of the literature and case series of ten patients

Spinal cord ependymoma (SCE) is a rare tumor that is most commonly low-grade. Complete surgical resection has been established as first-line treatment and can be curative. However, SCEs tend to recur when complete tumor resection is not possible. Evidence supporting the use of adjuvant radiation and chemotherapy is not definitive. We review the most recent literature on SCE covering a comprehensive range of topics spanning the biology, presentation, clinical management, and outcomes. In addition, we present a case series of ten SCE patients with the goal of contributing to existing knowledge of this rare disease.

Association of Overlapping Surgery With Patient Outcomes in a Large Series of Neurosurgical Cases

Importance Overlapping surgery (OS) is common. However, there is a dearth of evidence to support or refute the safety of this practice. Objective To determine whether OS is associated with worsened morbidity and mortality in a large series of neurosurgical cases. Design, Setting, and Participants A retrospective cohort study was completed for patients who underwent neurosurgical procedures at Emory University Hospital, a large academic referral hospital, between January 1, 2014, and December 31, 2015. Patients were operated on for pathologies across the spectrum of neurosurgical disorders. Propensity score weighting and logistic regression models were executed to compare outcomes for patients who received nonoverlapping surgery and OS. Investigators were blinded to study cohorts during data collection and analysis. Main Outcomes and Measures The primary outcome measures were 90-day postoperative mortality, morbidity, and functional status. Results In this cohort of 2275 patients who underwent neurosurgery, 1259 (55.3%) were female, and the mean (SD) age was 52.1 (16.4) years. A total of 972 surgeries (42.7%) were nonoverlapping while 1303 (57.3%) were overlapping. The distribution of American Society of Anesthesiologists score was similar between nonoverlapping surgery and OS cohorts. Median surgical times were significantly longer for patients in the OS cohort vs the nonoverlapping surgery cohort (in-room time, 219 vs 188 minutes; skin-to-skin time, 141 vs 113 minutes; both P < .001). Overlapping surgery was more frequently elective (93% vs 87%; P < .001). Regression analysis failed to demonstrate an association between OS and complications, such as mortality, morbidity, or worsened functional status. Measures of baseline severity of illness, such as admission to the intensive care unit and increased length of stay, were associated with mortality (intensive care unit: odds ratio [OR], 25.5; 95% CI, 6.22-104.67; length of stay: OR, 1.03; 95% CI, 1.00-1.05), morbidity (intensive care unit: OR, 1.85; 95% CI, 1.43-2.40; length of stay: OR, 1.06; 95% CI, 1.04-1.08), and unfavorable functional status (length of stay: OR, 1.03; 95% CI, 1.02-1.05). Conclusions and Relevance These data suggest that OS can be safely performed if appropriate precautions and patient selection are followed. Data such as these will help determine health care policy to maximize patient safety.

Jacket: GPU Powered MATLAB Acceleration

Publisher Summary Jacket is a software platform developed at AccelerEyes, which allows users to execute MATrix LABoratory (MATLAB) M-code on CUDA-capable graphics processing units (GPUs). MATLAB by the MathWorks is a standard platform for technical computing and graphics in science, engineering, and finance. The combination of a simple matrix language, interactive prompt, automatic memory management, and on-the-fly compilation make MATLAB well suited to rapid prototyping of algorithms and exploring data. MATLABs one drawback is performance, and Jacket alleviates this by seamless offloading of computations to the GPU. Jacket provides users access to a set of libraries, functions, and tools that facilitate numerical computation on the GPU including multi-GPU support built on MATLABs Parallel Computing Toolbox and Distributed Computing Server. Jacket has been designed for programmers who have large data-parallel tasks but who are not low level programmers accustomed to dealing with GPU-specific constructs. Once data is marked as “GPU” data using these functions, Jacket provides native GPU implementations of a large set of the standard MATLAB functions to operate on that data. Jacket achieves transparency by defining a new set of classes dubbed “g” objects, where each element of this set corresponds to a base class of the MATLAB standard interface—single, uint16, ones, etc. map to gsingle, guint16, gones, etc. The Jacket architecture uses object-oriented programming to handle references to data. Jacket includes a graphics toolbox that provides a simple method of displaying computational results on the GPU without bringing those results back to the host.

Processing and Visualization of Diffusion MRI

This chapter provides a survey of techniques for processing and visualization of diffusion magnetic resonance imagery. We describe various approaches to modeling the local diffusion structure from scanner measurements. In particular, we differentiate between parametric and non-parametric models, and describe regularization approaches. We then look at techniques to trace out neural pathways and infer global tissue structure. Deterministic, probabilistic, and global trajectories are analyzed, and techniques of validation are introduced. Last, we draw upon these as building blocks for the visualization and analysis of the neural architecture of individuals and groups. Special attention is drawn to volume segmentation, fiber clustering, and tissue analysis.

Cops and docs: The challenges for ED physicians balancing the police, state laws, and EMTALA

State laws are awash with discord concerning whether a police officers request or court order necessarily obligates physicians to perform a body fluid analysis of an arrested, conscious, nonconsenting suspect. Police typically bring arrestees directly to the emergency department (ED), and federal courts have begun to wrestle with the implications of the Emergency Medical Treatment and Labor Act (EMTALA), which requires that anyone presenting to the ED be screened for treatment. Some state laws require health care providers to comply with any police request for lab analysis, while other states offer more leeway to physicians. Recent trends in federal case law interpreting EMTALA suggest that a medical screening exam is not required for patients brought by police specifically for a blood or urine sample unless either the arrestee requests medical care or a prudent observer would believe medical care was indicated. This article answers two questions: What happens when a police officer presents to the ED requesting service on behalf of an arrestee? What does EMTLA require of physicians in response? We survey current state statutes, review recent state and federal case law, describe example policies from various hospitals, and conclude with recommendations for hospital risk managers.

Comparing Cortical Trajectory Transforaminal Lumbar Interbody Fusions Against Pedicle Trajectory Transforaminal Lumbar Interbody Fusions and Posterolateral Fusions: A Retrospective Cohort Study of 90-day Outcomes

BACKGROUND The cortical screw (CS) trajectory for pedicle screw placement is believed to require a smaller incision and less tissue dissection resulting in lower blood loss and faster healing; however, this has not yet been confirmed in clinical studies. OBJECTIVE To compare CS transforaminal lumbar interbody fusions (TLIF), traditional pedicle screw (TPS) trajectory TLIFs, and posterolateral fusion (PLF) without interbody for differences in operative characteristics and complications. METHODS We performed a retrospective cohort study (CS, TPS, and PLF) looking at patients who underwent lumbar fusion with 1 or 2 levels. Extracted data included demographics, comorbidities, estimated blood loss, transfusions, operative time, length of stay, discharge disposition (home vs rehabilitation), and complications within the perioperative, 30- and 90-d periods. RESULTS A total of 118 patients (45 CS, 35 TPS, and 38 PLF) were included with average age 62 and 90-d follow-up for 106 (90%) patients. CS had less average blood loss (231 ml) than either TPS (424, P = .0023) or PLF (400, P = .0070). CS had far fewer transfusions than either TPS or PLF (P < .0001). TPS had longer average operating room (OR) time (262 min) than either CS (214, P = .0075) or PLF (211, P = .0060). CS had the shortest length of postoperative stay (4.3 days) which was significantly shorter than PLF (6.2, P = .0138) but not different than TPS (4.8). There were no differences in discharge disposition, complications, perioperative, 30-d, 90-d, durotomy, or wound healing issues. CONCLUSION The CS trajectory is associated with less blood loss, fewer transfusions, reduced OR time, and shorter length of stay, with no difference in complications.

Tractography for Optic Radiation Preservation in Transcortical Approaches to Intracerebral Lesions

We present a case of intraventricular meningioma resected via a transcortical approach using tractography for optic radiation and arcuate fasciculus preservation. We include a review of the literature. A 54-year-old woman with a history of breast cancer presented with gait imbalance. Workup revealed a mass in the atrium of the left lateral ventricle consistent with a meningioma. Whole brain automated diffusion tensor imaging (DTI) was used to plan a transcortical resection while sparing the optic radiations and arcuate fasciculus. A left posterior parietal craniotomy was performed using the Synaptive BrightMatter™ frameless navigation (Synaptive Medical, Toronto, Canada) to minimally disrupt the white matter pathways. A gross total resection was achieved. Postoperatively, the patient had temporary right upper extremity weakness, which improved, and her visual fields and speech remained intact. Pathology confirmed a World Health Organization (WHO) Grade I meningothelial meningioma. While a thorough understanding of cortical anatomy is essential for safe resection of eloquent or deep-seated lesions, significant variability in fiber bundles, such as optic radiations and the arcuate fasciculus, necessitates a more individualized understanding of a patient’s potential surgical risk. The addition of enhanced DTI to the neurosurgeon’s armamentarium may allow for more complete resections of difficult intracerebral lesions while minimizing complications, such as visual deficit.