The Management of Intraoperative Spinal Cord Injury - A Scoping Review

STUDY DESIGN

Scoping Review.

OBJECTIVE

To review the literature and summarize information on checklists and algorithms for responding to intraoperative neuromonitoring (IONM) alerts and management of intraoperative spinal cord injuries (ISCIs).

METHODS

MEDLINE® was searched from inception through January 26, 2022 as were sources of grey literature. We attempted to obtain guidelines and/or consensus statements from the following sources: American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM), American Academy of Neurology (AAN), American Clinical Neurophysiology Society, NASS (North American Spine Society), and other spine surgery organizations.

RESULTS

Of 16 studies reporting on management strategies for ISCIs, two were publications of consensus meetings which were conducted according to the Delphi method and eight were retrospective cohort studies. The remaining six studies were narrative reviews that proposed intraoperative checklists and management strategies for IONM alerts. Of note, 56% of included studies focused only on patients undergoing spinal deformity surgery. Intraoperative considerations and measures taken in the event of an ISCI are divided and reported in three categories of i) Anesthesiologic, ii) Neurophysiological/Technical, and iii) Surgical management strategies.

CONCLUSION

There is a paucity of literature on comparative effectiveness and harms of management strategies in response to an IONM alert and possible ISCI. There is a pressing need to develop a standardized checklist and care pathway to avoid and minimize the risk of postoperative neurologic sequelae.

Definition, Frequency and Risk Factors for Intra-Operative Spinal Cord Injury: A Knowledge Synthesis

STUDY DESIGN

Mixed-methods approach.

OBJECTIVES

Intra-operative spinal cord injury (ISCI) is a devastating complication of spinal surgery. Presently, a uniform definition for ISCI does not exist. Consequently, the reported frequency of ISCI and important risk factors vary in the existing literature. To address these gaps in knowledge, a mixed-methods knowledge synthesis was undertaken.

METHODS

A scoping review was conducted to review the definitions used for ISCI and to ascertain the frequency of ISCI. The definition of ISCI underwent formal review, revision and voting by the Guidelines Development Group (GDG). A systematic review of the literature was conducted to determine the risk factors for ISCI. Based on this systematic review and GDG input, a table was created to summarize the factors deemed to increase the risk for ISCI. All reviews were done according to PRISMA standards and were registered on PROSPERO.

RESULTS

The frequency of ISCI ranged from 0 to 61%. Older age, male sex, cardiovascular disease including hypertension, severe myelopathy, blood loss, requirement for osteotomy, coronal deformity angular ratio, and curve magnitude were associated with an increased risk of ISCI. Better pre-operative neurological status and use of intra-operative neuromonitoring (IONM) were associated with a decreased risk of ISCI. The risk factors for ISCI included a rigid thoracic curve with high deformity angular ratio, revision congenital deformity with significant cord compression and myelopathy, extrinsic intradural or extradural lesions with cord compression and myelopathy, intramedullary spinal cord tumor, unstable spine fractures (bilateral facet dislocation and disc herniation), extension distraction injury with ankylosing spondylitis, ossification of posterior longitudinal ligament (OPLL) with severe cord compression, and moderate to severe myelopathy.

CONCLUSIONS

ISCI has been defined as "a new or worsening neurological deficit attributable to spinal cord dysfunction during spine surgery that is diagnosed intra-operatively via neurophysiologic monitoring or by an intraoperative wake-up test, or immediately post-operatively based on clinical assessment". This paper defines clinical and imaging factors which increase the risk for ISCI and that could assist clinicians in decision making.

Prevention, Diagnosis, and Management of Intraoperative Spinal Cord Injury in the Setting of Spine Surgery: A Proposed Care Pathway

STUDY DESIGN

This study is a mixed methods approach.

OBJECTIVES

Intraoperative spinal cord injury (ISCI) is a challenging complication in spine surgery. Intra-operative neuromonitoring (IONM) has been developed to detect changes in neural function. We report on the first multidisciplinary, international effort through AO Spine and the Praxis Spinal Cord Institute to develop a comprehensive guideline and care pathway for the prevention, diagnosis, and management of ISCI.

METHODS

Three literature reviews were registered on PROSPERO (CRD 42022298841) and performed according to PRISMA guidelines: (1) Definitions, frequency, and risk factors for ISCI, (2) Meta-analysis of the accuracy of IONM for diagnosis of ISCI, (3) Reported management approaches for ISCI and related events. The results were presented in a consensus session to decide the definition of IONM and recommendation of its use in high-risk cases. Based on a literature review of management strategies for ISCI, an intra-operative checklist and overall care pathway was developed by the study team.

RESULTS

An operational definition and high-risk patient categories for ISCI were established. The reported incidence of deficits was documented to be higher in intramedullary tumour spine surgery. Multimodality IONM has a high sensitivity and specificity. A guideline recommendation of IONM to be employed for high-risk spine cases was made. The different sections of the intraoperative checklist include surgery, anaesthetic and neurophysiology. The care pathway includes steps (1) initial clinical assessment, (2) pre-operative planning, (3) surgical/anaesthetic planning, (4) intra-operative management, and (5) post-operative management.

CONCLUSIONS

This is the first evidence based comprehensive guideline and care pathway for ISCI using the GRADE methodology. This will facilitate a reduction in the incidence of ISCI and improved outcomes from this complication. We welcome the wide implementation and validation of these guidelines and care pathways in prospective, multicentre studies.

A Clinical Practice Guideline for Prevention, Diagnosis and Management of Intraoperative Spinal Cord Injury: Recommendations for Use of Intraoperative Neuromonitoring and for the Use of Preoperative and Intraoperative Protocols for Patients Undergoing Spine Surgery

STUDY DESIGN

Development of a clinical practice guideline following the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) process.

OBJECTIVE

The objectives of this study were to develop guidelines that outline the utility of intraoperative neuromonitoring (IONM) to detect intraoperative spinal cord injury (ISCI) among patients undergoing spine surgery, to define a subset of patients undergoing spine surgery at higher risk for ISCI and to develop protocols to prevent, diagnose, and manage ISCI.

METHODS

All systematic reviews were performed according to PRISMA standards and registered on PROSPERO. A multidisciplinary, international Guidelines Development Group (GDG) reviewed and discussed the evidence using GRADE protocols. Consensus was defined by 80% agreement among GDG members. A systematic review and diagnostic test accuracy (DTA) meta-analysis was performed to synthesize pooled evidence on the diagnostic accuracy of IONM to detect ISCI among patients undergoing spinal surgery. The IONM modalities evaluated included somatosensory evoked potentials (SSEPs), motor evoked potentials (MEPs), electromyography (EMG), and multimodal neuromonitoring. Utilizing this knowledge and their clinical experience, the multidisciplinary GDG created recommendations for the use of IONM to identify ISCI in patients undergoing spine surgery. The evidence related to existing care pathways to manage ISCI was summarized and based on this a novel AO Spine-PRAXIS care pathway was created.

RESULTS

Our recommendations are as follows: (1) We recommend that intraoperative neurophysiological monitoring be employed for high risk patients undergoing spine surgery, and (2) We suggest that patients at "high risk" for ISCI during spine surgery be proactively identified, that after identification of such patients, multi-disciplinary team discussions be undertaken to manage patients, and that an intraoperative protocol including the use of IONM be implemented. A care pathway for the prevention, diagnosis, and management of ISCI has been developed by the GDG.

CONCLUSION

We anticipate that these guidelines will promote the use of IONM to detect and manage ISCI, and promote the use of preoperative and intraoperative checklists by surgeons and other team members for high risk patients undergoing spine surgery. We welcome teams to implement and evaluate the care pathway created by our GDG.

Early surgical intervention for acute spinal cord injury: time is spine

Acute traumatic spinal cord injury (tSCI) is a devastating occurrence that significantly contributes to global morbidity and mortality. Surgical decompression with stabilization is the most effective way to minimize the damaging sequelae that follow acute tSCI. In recent years, strong evidence has emerged that supports the rationale that early surgical intervention, within 24 h following the initial injury, is associated with a better prognosis and functional outcomes. In this review, we have summarized the evidence and elaborated on the nuances of this concept. Additionally, we have reviewed further concepts that stem from "time is spine," including earlier cutoffs less than 24 h and the challenging entity of central cord syndrome, as well as the emerging concept of adequate surgical decompression. Lastly, we identify barriers to early surgical care for acute tSCI, a key aspect of spine care that needs to be globally addressed via research and policy on an urgent basis.

Tip-over injuries among children: Data from an urban emergency department of Karachi, Pakistan

INTRODUCTION

Most unintentional injuries among children occur in the home environment. Tip-overs, defined as incidents where heavy objects fall on children due to some type of interaction, are one of the reasons for injuries inside the home. This study aims to determine injury patterns and outcomes for child injuries resulting from tip-overs in the home environment as reported in the emergency department.

METHODS

We performed a retrospective chart review of pediatric (under 18 years) tip-overs injuries occurred in years 2010 to 2015 at the Aga Khan University Hospital. Furthermore, parents of injured children participated in phone interviews to provide information about the injury scene. File review and telephonic interviews were conducted in the year 2015 and 2016.

RESULTS

A total of 75 children visited the emergency department with tip-over injuries, out of which 55 (73%) were boys. The majority of incidents (75.5%) happened inside the home, and the most common places were the living room and bedroom (32% and 21% respectively). More than half (53%) of the children were not under adult supervision at the time of the incident and less than half (47%) of the household took safety measures after the incident. Tip-over injuries were common among 3-year-old children with decreasing frequency as children grew older. The most common causes of tip-overs were TV/TV trolley (32%), followed by furniture (28%), and wall and roof (23%). The most common sites of injuries were head (n = 33, 44%) and extremities (n = 33, 44%). A majority of the cases (n = 66, 88%) were admitted to the hospital from the emergency department, under care of both general (n = 51, 68%) and critical care units (n = 15, 20%). More than a quarter (n = 27, 36%) required at least one surgical procedure during their hospital stay. The median length of hospital stay was one days (interquartile range, IQR 1-5 days). There were two cases of mortality (3%).

CONCLUSION

Most tip-over injuries among children were caused by TV, furniture, and TV trolleys. These injuries can be prevented with public education around home safety measures, such as mounting them on the wall.

Degenerative cervical myelopathy: Where have we been? Where are we now? Where are we going?

Degenerative cervical myelopathy (DCM), a recently coined term, encompasses a group of age-related and genetically associated pathologies that affect the cervical spine, including cervical spondylotic myelopathy and ossification of the posterior longitudinal ligament (OPLL). Given the significant contribution of DCM to global disease and disability, there are worldwide efforts to promote research and innovation in this area. An AO Spine effort termed 'RECODE-DCM' was initiated to create an international multistakeholder consensus group, involving patients, caregivers, physicians and researchers, to focus on launching actionable discourse on DCM. In order to improve the management, treatment and results for DCM, the RECODE-DCM consensus group recently identified ten priority areas for translational research. The current article summarizes recent advancements in the field of DCM. We first discuss the comprehensive definition recently refined by the RECODE-DCM group, including steps taken to arrive at this definition and the supporting rationale. We then provide an overview of the recent advancements in our understanding of the pathophysiology of DCM and modalities to clinically assess and diagnose DCM. A focus will be set on advanced imaging techniques that may offer the opportunity to improve characterization and diagnosis of DCM. A summary of treatment modalities, including surgical and nonoperative options, is then provided along with future neuroprotective and neuroregenerative strategies. This review concludes with final remarks pertaining to the genetics involved in DCM and the opportunity to leverage this knowledge toward a personalized medicine approach.

Diagnostic Implications of White Matter Tract Involvement by Intra-axial Brain Tumors

Introduction

Diffusion tensor imaging (DTI) is being increasingly used during brain tumor surgery. However, there is limited data available on its diagnostic and prognostic value. Our objective was to assess the pattern of involvement of white matter tracts (WMTs) by intra-axial brain tumors on DTI. Secondary objectives were to evaluate implications of involvement of WMT on surgical resection, and the post-operative functional outcome.

Methods

This was a retrospective study of consecutive patients, who underwent DTI-guided surgery for brain tumors. The involvement of WMTs by tumors on DTI was assessed by a radiologist (who was blind to the pathology) using the Witwer classification. The pathology was reported by histopathologists using the World Health Organization brain tumor classification. Karnofsky Performance Status Scale (KPS) was used for assessing patients’ neurological status at admission, and at follow-up.

Results

Forty-five (58.4%) out of 77 tumors reviewed caused infiltration of WMTs, whereas only 22 (28.6%) tumors caused displacement of WMTs (p= 0.040). Among 32 cases of astrocytoma, the involvement of WMTs was influenced by the grade of tumor (p= 0.012), as high-grade tumors caused infiltration (19; 59.4%), unlike low-grade tumors that commonly caused displacement (2; 50%). Oligodendrogliomas caused infiltration/disruption of WMTs in most cases, irrespective of the grade (19 out of 25 cases; 76%). At the last follow-up, 27 (35.1%) patients showed improvement in KPS and 14 (18.2%) reported deterioration, while there was no change observed in 36 (46.8%) patients. The infiltration of WMTs was associated with a poor functional outcome.

Conclusions

High-grade astrocytomas mostly cause infiltration of WMTs, unlike oligodendrogliomas, which often infiltrate WMTs, irrespective of the tumor grade. The infiltration of WMTs is associated with a poor functional outcome at follow-ups.

NCOG-46. WHITE MATTER TRACT INVOLVEMENT BY INTRA-AXIAL BRAIN TUMORS; DIAGNOSTIC & THERAPEUTIC IMPLICATIONS

Diffusion tensor imaging (DTI) is a relatively recent modality which aids in visualization of WMT and their relation to intracranial lesions. Despite almost two decades since the beginning of its use in tumor resection, there is still dearth of data on its diagnostic and prognostic value from low- and middle-income countries. We aimed to assess the pattern of involvement of white matter tracts (WMT) by intra-axial brain tumors on DTI. Secondary objectives were to evaluate implications of involvement of WMT on surgical resection, and post-operative functional outcome. This was a retrospective study of 77 consecutive patients, who underwent DTI guided surgery for brain tumors. The involvement of WMT by tumors on DTI was assessed by a radiologist (who was blind to the pathology) using the Witwer classification. The pathology was reported by histopathologists using WHO brain tumor classification. Karnofsky Performance Scale (KPS) was used for assessing patients’ neurological status at admission, and at follow-up. Forty-five (58.4%) out of 77 tumors reviewed, caused infiltration of WMT, whereas only 22 (28.6%) tumors caused displacement of WMT (p = 0.040). Among 32 cases of astrocytoma, involvement of WMTs was influenced by the grade of tumor (p = 0.012), as high-grade tumors caused infiltration (19; 59.4%), unlike low grade tumors which commonly caused displacement (2; 50%). Oligodendroglioma caused infiltration/disruption of WMTs in most cases, irrespective of the grade (19 out of 25 cases; 76%). At last follow-up, 27 (35.1%) patients showed improvement in KPS and 14 (18.2%) reported deterioration, while there was no change observed in 36 (46.8%) patients. Infiltration of WMTs was associated with poor functional outcome. We conclude that intra-axial brain tumors mostly cause infiltration of WMTs, particularly high-grade astrocytoma, and oligodendroglioma of any grade. Infiltration of WMTs is associated with poor functional outcome at follow-up.

Enhanced Recovery After Surgery strategies for elective craniotomy: a systematic review

OBJECTIVE

Enhanced Recovery After Surgery (ERAS) has led to a paradigm shift in perioperative care through multimodal interventions. Still, ERAS remains a relatively new concept in neurosurgery, and there is no summary of evidence on ERAS applications in cranial neurosurgery.

METHODS

The authors systematically reviewed the literature using the PubMed/MEDLINE, Embase, Scopus, and Cochrane Library databases for ERAS protocols and elements. Studies had to assess at least one pre-, peri-, or postoperative ERAS element and evaluate at least one of the following outcomes: 1) length of hospital stay, 2) length of ICU stay, 3) postoperative pain, 4) direct and indirect healthcare cost, 5) complication rate, 6) readmission rate, or 7) patient satisfaction.

RESULTS

A final 27 articles were included in the qualitative analysis, with mixed quality of evidence ranging from high in 3 cases to very low in 1 case. Seventeen studies reported a complete ERAS protocol. Preoperative ERAS elements include patient selection through multidisciplinary team discussion, patient counseling and education to adjust expectations of the postoperative period, and mental state assessment; antimicrobial, steroidal, and antiepileptic prophylaxes; nutritional assessment, as well as preoperative oral carbohydrate loading; and postoperative nausea and vomiting (PONV) prophylaxis. Anesthesiology interventions included local anesthesia for pin sites, regional field block or scalp block, avoidance or minimization of the duration of invasive monitoring, and limitation of intraoperative mannitol. Other intraoperative elements include absorbable skin sutures and avoidance of wound drains. Postoperatively, the authors identified early extubation, observation in a step-down unit instead of routine ICU admission, early mobilization, early fluid de-escalation, early intake of solid food and liquids, early removal of invasive monitoring, professional nutritional assessment, PONV management, nonopioid rescue analgesia, and early postoperative imaging. Other postoperative interventions included discharge criteria standardization and home visits or progress monitoring by a nurse.

CONCLUSIONS

A wide range of evidence-based interventions are available to improve recovery after elective craniotomy, although there are few published ERAS protocols. Patient-centered optimization of neurosurgical care spanning the pre-, intra-, and postoperative periods is feasible and has already provided positive results in terms of improved outcomes such as postoperative pain, patient satisfaction, reduced length of stay, and cost reduction with an excellent safety profile. Although fast-track recovery protocols and ERAS studies are gaining momentum for elective craniotomy, prospective trials are needed to provide stronger evidence.

Hemorrhagic complications after decompressive craniectomy

Background:

Decompressive craniectomy (DC) is the preferred surgical management option for lowering refractory intracranial pressure in cases of traumatic brain injury (TBI). A number of randomized controlled trials have demonstrated decreased mortality but increased morbidity following DC for TBI patients. Here, we reviewed the frequency of postoperative hemorrhagic complications following DC correlating with poor outcomes.

Methods:

We retrospectively reviewed the medical records of patients who presented with TBI and underwent DC during the years 2015–2017. The frequency and characteristics of hemorrhagic complications were correlated with the patients’ outcomes.

Results:

There were 74 patients with TBI included in the study who underwent DC. Of these, 31 patients developed expansion of existing hemorrhagic lesions, 13 had new contusions, three developed new extradural hemorrhages, two developed new subdural hematomas, and one patient developed an intraventricular hemorrhage. Those who developed expansion of existing hemorrhagic lesions following DC had longer ICU stays and poorer outcomes (Glasgow outcome scale).

Conclusion:

After 74 DC performed in TBI patients, 67% developed new hemorrhagic lesions or expansion of previously existing hemorrhages. This finding negatively impacted clinical outcomes, including mortality.

Normative data of a smartphone app-based 6-minute walking test, test-retest reliability, and content validity with patient-reported outcome measures

OBJECTIVE

The 6-minute walking test (6WT) is used to determine restrictions in a subject's 6-minute walking distance (6WD) due to lumbar degenerative disc disease. To facilitate simple and convenient patient self-measurement, a free and reliable smartphone app using Global Positioning System coordinates was previously designed. The authors aimed to determine normative values for app-based 6WD measurements.

METHODS

The maximum 6WD was determined three times using app-based measurement in a sample of 330 volunteers without previous spine surgery or current spine-related disability, recruited at 8 centers in 5 countries (mean subject age 44.2 years, range 16-91 years; 48.5% male; mean BMI 24.6 kg/m2, range 16.3-40.2 kg/m2; 67.9% working; 14.2% smokers). Subjects provided basic demographic information, including comorbidities and patient-reported outcome measures (PROMs): visual analog scale (VAS) for both low-back and lower-extremity pain, Core Outcome Measures Index (COMI), Zurich Claudication Questionnaire (ZCQ), and subjective walking distance and duration. The authors determined the test-retest reliability across three measurements (intraclass correlation coefficient [ICC], standard error of measurement [SEM], and mean 6WD [95% CI]) stratified for age and sex, and content validity (linear regression coefficients) between 6WD and PROMs.

RESULTS

The ICC for repeated app-based 6WD measurements was 0.89 (95% CI 0.87-0.91, p < 0.001) and the SEM was 34 meters. The overall mean 6WD was 585.9 meters (95% CI 574.7-597.0 meters), with significant differences across age categories (p < 0.001). The 6WD was on average about 32 meters less in females (570.5 vs 602.2 meters, p = 0.005). There were linear correlations between average 6WD and VAS back pain, VAS leg pain, COMI Back and COMI subscores of pain intensity and disability, ZCQ symptom severity, ZCQ physical function, and ZCQ pain and neuroischemic symptoms subscores, as well as with subjective walking distance and duration, indicating that subjects with higher pain, higher disability, and lower subjective walking capacity had significantly lower 6WD (all p < 0.001).

CONCLUSIONS

This study provides normative data for app-based 6WD measurements in a multicenter sample from 8 institutions and 5 countries. These values can now be used as reference to compare 6WT results and quantify objective functional impairment in patients with degenerative diseases of the spine using z-scores. The authors found a good to excellent test-retest reliability of the 6WT app, a low area of uncertainty, and high content validity of the average 6WD with commonly used PROMs.

Initial classification of low back and leg pain based on objective functional testing: a pilot study of machine learning applied to diagnostics

OBJECTIVE

The five-repetition sit-to-stand (5R-STS) test was designed to capture objective functional impairment and thus provided an adjunctive dimension in patient assessment. The clinical interpretability and confounders of the 5R-STS remain poorly understood. In clinical use, it became apparent that 5R-STS performance may differ between patients with lumbar disk herniation (LDH), lumbar spinal stenosis (LSS) with or without low-grade spondylolisthesis, and chronic low back pain (CLBP). We seek to evaluate the extent of diagnostic information contained within 5R-STS testing.

METHODS

Patients were classified into gold standard diagnostic categories based on history, physical examination, and imaging. Crude and adjusted comparisons of 5R-STS performance were carried out among the three diagnostic categories. Subsequently, a machine learning algorithm was trained to classify patients into the three categories using only 5R-STS test time and patient age, gender, height, and weight.

RESULTS

From two prospective studies, 262 patients were included. Significant differences in crude and adjusted test times were observed among the three diagnostic categories. At internal validation, classification accuracy was 96.2% (95% CI 87.099.5%). Classification sensitivity was 95.7%, 100%, and 100% for LDH, LSS, and CLBP, respectively. Similarly, classification specificity was 100%, 95.7%, and 100% for the three diagnostic categories.

CONCLUSION

5R-STS performance differs according to the etiology of back and leg pain, even after adjustment for demographic covariates. In combination with machine learning algorithms, OFI can be used to infer the etiology of spinal back and leg pain with accuracy comparable to other diagnostic tests used in clinical examination. These slides can be retrieved under Electronic Supplementary Material.

Dengue and malaria infections in pregnancy : Maternal, fetal and neonatal outcomes at a tertiary care hospital

Background

Malaria and dengue cause major morbidity in developing nations and are more severe in pregnancy. Maternal, fetal, and neonatal outcomes in pregnant patients infected with dengue or malaria were studied.

Methods

The medical records of pregnant women admitted with either dengue or malaria infections from 2011–2015 to this hospital were reviewed. Clinical outcomes and laboratory tests were examined.

Results

Of 85 women, 56%, 21%, and 22% had contracted dengue, malaria, and multiple infections, respectively. Pregnant women who had contracted dengue fever alone were more likely to present to the hospital at an earlier gestational age (24 weeks, p = 0.03). Women with multiple infections, were more likely to deliver earlier (30 weeks, p < 0.01). Women with malaria were more likely to have low birth weight deliveries (mean birth weight 2394 g, p = 0.03). The incidence of in-hospital deaths among the cohort was 7%.

Conclusion

It is imperative to develop guidelines to screen for and diagnose dengue and malaria in pregnancy.

Electronic supplementary material

The online version of this article (10.1007/s00508-019-01606-8) contains supplementary material, which is available to authorized users.

Selection of preclinical models to evaluate intranasal brain cooling for acute ischemic stroke

Stroke accounts for a large proportion of global mortality and morbidity. Selective hypothermia, via intranasal cooling devices, is a promising intervention in acute ischemic stroke. However, prior to large clinical trials, preclinical studies in large animal models of ischemic stroke are needed to assess the efficacy, safety, and feasibility of intranasal cooling for selective hypothermia as a neuroprotective strategy. Here, we review the available scientific literature for evidence supporting selective hypothermia and make recommendations of a preclinical, large, animal-based, ischemic stroke model that has the greatest potential for evaluating intranasal cooling for selective hypothermia and neuroprotection. We conclude that among large animal models of focal ischemic stroke including pigs, sheep, dogs, and nonhuman primates (NHPs), cynomolgus macaques have nasal anatomy, nasal vasculature, neuroanatomy, and cerebrovasculature that are most similar to those of humans. Moreover, middle cerebral artery stroke in cynomolgus macaques produces functional and behavioral deficits that are quantifiable to a greater degree of precision and detail than those that can be revealed through available assessments for other large animals. These NHPs are also amenable to extensive neuroimaging studies as a means of monitoring stroke evolution and evaluating infarct size. Hence, we suggest that cynomolgus macaques are best suited to assess the safety and efficacy of intranasal selective hypothermia through an evaluation of hyperacute diffusion-weighted imaging and subsequent investigation of chronic functional recovery, prior to randomized clinical trials in humans.

Factors affecting post-operative recurrence or growth of meningiomas, other than histological grade and extent of resection

Meningiomas are one of the commonest primary brain tumours, treated primarily with surgery. These are extraaxial tumours and their post-operative recurrence rates have been extensively studied. The most established predictor of meningioma recurrence is the WHO grade (based on histological features) and the Simpson grade, based on the extent of resection. In this review article, we look into the risk factors other than histological grade and Simpson grade that have been associated with recurrence of meningioma after resection.

Anterolateral Approach for a Cervical Nerve Root Compression Syndrome Due to an Ectatic Vertebral Artery

BACKGROUND AND IMPORTANCE

Nerve root compression by an ectatic vertebral artery is a known but easily overlooked cause of cervical radiculopathy. Management options include nonoperative conservative therapies or surgical approaches designed to relieve the compression via anterior or posterior cervical approaches.

CLINICAL PRESENTATION

A 72-yr-old female presented with a 6-mo history of sharp, shooting pain in her right arm and shoulder and deltoid weakness. Imaging demonstrated a vertebral artery loop compressing the proximal right C5 nerve root. She previously underwent both nonoperative measures as well as posterior foraminotomy at this level with limited improvement in her pain. Therefore, we performed an anterolateral approach for vascular decompression of the C5 nerve root from the vertebral artery loop. Patient has been pain-free at 1 yr with full recovery of her deltoid weakness.

CONCLUSION

Vertebral artery loop formation is an uncommon cause of cervical radiculopathy, which can be readily treated by vascular decompression of the nerve root-vertebral artery loop complex. Although anomalous vertebral artery compression of a cervical nerve root is rare, it is increasingly being recognized as a readily treatable entity that can lead to lasting and full neurological recovery. We also include an operative video to illustrate the vascular decompression of an ectatic vertebral artery causing severe cervical radiculopathy.

Effect of pregnancy on growth of intracranial meningiomas

Meningiomas are the most common benign primary intracranial tumours in adults. Their rapid growth during pregnancy has been well reported. Moreover, the relationship of increased progesterone expression during pregnancy and extensive tumour growth has been debated. In this review, we discuss not only the effect of progesterone on meningiomal growth but also other mechanisms involved in gestational meningiomas.

Serum biomarkers for glioblastoma multiforme

A number of different serum biomarkers are currently being evaluated for their potential use as diagnostic and prognostic biomarkers in Glioblastoma Multiforme. Amongst these, a vast number of different microRNAs have been studied, that are up-regulated or downregulated in relation to Glioblastoma Multiforme. Different studies have found numerous associations of these different microRNAs with recurrence, Karnofsky Performance Score, Progression Free Survival and Overall Survival. Other than microRNAs, serum Glial Fibrillary Acid Protein, cytokines and YLK-40, as well as a number of other candidate serum biomarkers are being studied.More studies, with larger sample sizes are required before these serum biomarkers can be routinely, and reliably used in clinical practice. Use of serum biomarkers can provide a non-invasive means for diagnosing and monitoring disease.

The significance of MGMT methylation in Glioblastoma Multiforme prognosis

Methylation of O6-methylguanine-DNA methyltransferase (MGMT) has been extensively studied as a biomarker in predicting the prognosis of patients with GBM (Glioblastoma multiforme). Its significance has been studied in various subgroups, including age, gender and even race. Correlation between prognosis with MGMT methylation and different treatment regimens has also been studied in detail. There are multiple techniques to analyze MGMT methylation in tumour specimen. We review the current evidence for the importance of MGMT methylation as a biomarker for prognosis in GBM patients, the techniques to analyze it and the effect of epidemiologic factors on its significance.

Simpson grading as predictor of meningioma recurrence

Meningimas are one of the commonest primary brain tumours and the commonest extra-axial primary brain tumour. Despite better understanding of the molecular pathogenesis of the tumours, surgical excision remains the treatment of choice, and in a large proportion of cases, complete excision is curative. Simpson grading for the extent of resection of meningiomas, was introduced more than six decades ago, and has stood the test of time. With modern technological advancements, however, the relevance of Simpson grading has been questioned. Herein we review the recent literature on the relevance of Simpson grading more than sixty years after its introduction.

Self-resolving prepontine cyst

BACKGROUND

Intracranial prepontine cysts are rare and include epidermoid cysts, arachnoid cysts, and neurenteric cysts. Symptomatic prepontine cysts may require surgical intervention. Reports of spontaneous resolution of cysts are rare.

CASE DESCRIPTION

We describe the case of a young gentleman who presented with headache and fever. Magnetic resonance imaging of the brain identified a prepontine lesion with features consistent with epidermoid cyst. During admission, the patient received symptomatic management in addition to empirical antibiotic therapy and dexamethasone. The patient improved symptomatically in the next 48 hours and was discharged. Follow-up imaging at 6 months and 1 year showed significant reduction in size of the lesion.

CONCLUSION

For asymptomatic prepontine cysts, a close radiological and clinical follow-up may prove useful.

Diffuse mesangial sclerosis in a fetus

An 18-week fetus was born following termination of pregnancy by prostaglandin induction. Pregnancy was terminated because of elevated maternal serum alpha-fetoprotein and ultrasonographic evidence of severe oligohydramnios, intrauterine growth retardation, non-visualization of the bladder, dolichocephaly and possible mild hydrocephalus. Pathologic examination disclosed diffuse mesangial sclerosis and histologic evidence of the nephrotic syndrome. To our knowledge this is the first reported example of ante-natal diffuse mesangial sclerosis; of fetal congenital nephrosis other than Finnish type; and of fetal congenital nephrosis with prominent glomerular lesions.