When does too little pressure become too much? A case of spontaneous intracranial hypotension presenting with acute loss of consciousness.

Background: We present a unique case of spontaneous intracranial hypotension (SIH) presenting with acute collapse and loss of consciousness. Case Description: The affected patient suffered an abrupt decline in level of consciousness several weeks after initial diagnosis. The patient was urgently transferred to a specialist neurosurgical unit. Imaging showed bilateral subdural fluid collections with significant associated local mass effect. The treating team faced a clinical conundrum with a lack of clarity as to whether this sudden deterioration was secondary to the local pressure effect on brainstem traction from reduced intracranial pressure. A decision was made to proceed with urgent burr-hole decompression of the bilateral subdural fluid collections. Conclusion: After a protracted, complex postoperative course, the patient recovered to full functional independence. To the author's knowledge, this is the first case in literature describing successful surgical management of SIH, with bilateral burr-hole evacuation to relieve the paradoxical mass effect of bilateral subdural fluid collections.

Technical note: Novel use of recombinant tissue plasminogen activator for the evacuation of an acute extensive spinal epidural haematoma in a patient with coagulopathy.

Spontaneous extensive spinal epidural haematoma poses a unique challenge for the neurosurgeon. Performing extensive laminectomies to remove all of the compressive haematoma can destabilise the patient's spinal column, which may require fixation. This is further complicated in patients with significant coagulopathy. We present a novel use of recombinant tissue plasminogen activator (rt-PA) in a patient with therapeutic coagulopathy, presenting with myelopathy secondary to an acute extensive spinal epidural haematoma. To the best of our knowledge, this is the first case of acute multilevel spinal epidural haematoma that has been successfully evacuated via single level laminectomy and topically applied rt-PA.

Ethico-legal regional differences in European neurosurgical practice: Part 1-pre-COVID-19 era.

Introduction: Professionalism entails expert knowledge, self-regulation, accountability, and professional ethics. These factors are influenced by culture, political observance, professional maturity, education, and occupation; ethical practices may thus vary between countries and affect how neurosurgery is practiced. Research question: This paper aims to conduct a survey that addresses whether ethico-legal practices differ in European countries and whether existing ethical guidelines have been implemented. Material and methods: A questionnaire survey was used to examine the ethico-legal situation in 29 European countries or regions. The reports were validated by representatives of each nation. Results: Existing guidelines had been implemented to a minimal extent. Major regional and national differences were found in attitudes toward life and death, prioritization, and issues related to professional conduct. Discussion and conclusion: The results of this survey reveal inadequacies and weaknesses of policies and resources, which should spark national discussions to improve the conditions that influence professional ethics. Unfortunately, only a minority of neurosurgeons know the neurosurgical ethics guidelines and apply them in their decision making. Our findings highlight the importance of values and professional ethics in decision making.

Neurotrauma admissions and COVID-19: a National Centre experience.

BACKGROUND: To investigate the impact of COVID-19 on trauma admissions to a National Neurosurgical Centre in Ireland. METHODS: Retrospective analysis of a prospectively maintained database of all trauma admissions to the National Neurosurgical Centre at Beaumont Hospital, Dublin, during the period March 1 to May 31, 2019 and 2020. Primary outcome was 30-day mortality rate. Secondary outcomes included time transfer time, time from admission to time of surgery, and intensive care unit (ICU) admissions. Patients under the age of 16 were excluded. RESULTS: A total of 32 and 39 patients were admitted to the National Neurosurgical Centre following trauma over the 3-month period in 2020 and 2019 respectively, giving a 17.9% reduction in admissions. The 30-day mortality rate increased from 7.7% in 2019 to 15.6% on 2020 (p = 0.45). Mean transfer time was 4 h 58 min in 2019 and 3 h 55 min in 2020 (0.22). Mean time from admission to time of surgery was 9 h 10 min in 2019 and 5 h 37 min in 2020 respectively (p = 0.35). In 2019, 20 patients (51.3%) were admitted to ICU. This increased to 23 patients (69.7%) in 2020 (p = 0.08). CONCLUSIONS: Traumatic brain injury 30-day mortality rates increased during the first COVID-19 lockdown period. Trauma admission rates to ICU remained unchanged despite an overall reduction in trauma admissions. Transfer time, time to surgery, and length of stay were impacted by COVID-19. Despite the challenges COVID-19 has posed, it is important to maintain a fully functioning neurosurgical and neurocritical care service during the pandemic.

Should neurosurgeons continue to work in the absence of personal protective equipment during the COVID-19 era?

The COVID-19 pandemic has resulted in a widespread shortage of personal protective equipment (PPE). Many healthcare workers, including neurosurgeons, have expressed concern about how to safely and adequately perform their medical responsibilities in these challenging circumstances. One of these concerns revolves around the pressing question: should providers continue to work in the absence of adequate PPE? Although the first peak of the COVID-19 crisis seems to have subsided and supply of PPE has increased, concerns about insufficient PPE availability remain. Inconsistent supply, limited efficacy, and continued high demand for PPE, combined with the continued threat of a second COVID-19 wave, mean that the issues surrounding PPE availability remain unresolved, including a duty to work. This paper offers an ethical investigation of whether neurosurgeons should perform their professional responsibilities with limited availability of PPE. We evaluate ethical considerations and conflicting duties and thereby hope to facilitate providers in making a well-considered personal and moral decision about this challenging issue.

The impact of COVID-19 on trauma referrals to a National Neurosurgical Centre.

BACKGROUND: To investigate the impact of COVID-19 on trauma referrals to a National Neurosurgical Centre during the first wave of COVID-19 in Ireland. METHODS: Retrospective analysis of a prospectively maintained database of all trauma referrals to the National Neurosurgical Centre at Beaumont Hospital, Dublin, during the period March 1-May 31, 2019 and 2020. Patient characteristics including age, sex, alcohol use, anticoagulant/antiplatelet use and initial Glasgow Coma Scale (GCS) were recorded. Patients were grouped based on trauma aetiology and diagnosis. RESULTS: There were 527 and 437 trauma referrals in 2019 and 2020 respectively. Overall, there was a 17.1% reduction in trauma referrals between 2019 and 2020. Traumatic brain injury, spinal injury and cranial fractures referrals reduced 25% (375 vs 283), 59% (32 vs 13) and 18% (39 vs 32) respectively from 2019 to 2020. Low-energy falls below 2 m was the most common mechanism of injury and accounted for 60 and 61% of referrals in 2019 and 2020. No reduction in road traffic collision (33 vs 34) and assault (40 vs 40) referrals were observed between years. CONCLUSIONS: COVID-19 has had a significant impact on both the volume and mechanism of trauma referrals to the National Neurosurgical Centre in Ireland, with falls below 2 m the most common mechanism of trauma referral across both years. The workload remains substantial and a fully resourced neurosurgical department is essential in any future COVID-19 waves.

Bilateral laminotomy through a unilateral approach (minimally invasive) versus open laminectomy for lumbar spinal stenosis.

PURPOSE: To compare the outcomes of minimally invasive (MI) bilateral laminotomy via unilateral approach versus open laminectomy in the treatment of lumbar spinal stenosis (LSS). MATERIALS AND METHODS: In this prospective study, 62 patients were treated for LSS and were assigned to one of two groups over a 6-month period. Group A comprised 37 patients that underwent MI bilateral laminotomy. Group B comprised 25 patients that underwent open laminectomy. Follow-up duration was 3 years. The primary outcomes were the visual analogue scale (VAS) pain outcome score for back and leg, the Oswestry Disability Index (ODI) and complications. RESULTS: MI methods were superior in most primary outcomes compared to open laminectomy. VAS back pain outcome was reduced from close to 7 to 4 in both groups. VAS leg pain was reduced from 6.8 to 3.2 in MI group and from 8.7 to 3.5 in the open group (p > 0.05 between groups, p < 0.05 comparing pre- to post-operative back and leg pain). ODI improved from 56.5 to 13 and 58 to 24 in MI and open groups, respectively (p > 0.05 between groups, p < 0.05 comparing pre- to post-operative disability). Complication and revision rates were lower in the MI technique than open laminectomy (8 versus 56%, p < 0.05; 3 versus 12%, p > 0.05). Length of stay ranges were less in MI than open group (1-3 versus 7-30 days, p > 0.05). CONCLUSIONS: Bilateral laminotomy through a unilateral approach (minimally invasive) and open laminectomy are both effective in improving pain and disability in LSS. MI procedures have an advantage in shorter hospital stays, sparing of more bony structures and lower complication rates. MI unilateral decompression is at least as good as laminectomy in the treatment of LSS.

Intermixed arteriovenous malformation and hemangioblastoma: case report and literature review.

We report the third presentation of an intermixed arteriovenous malformation and hemangioblastoma. The rare occurrence of the diagnostic histologic features of both a neoplasm and vascular malformation in a single lesion is more common in gliomas, as angioglioma, and is termed an 'intermixed' lesion. We review the literature concerning the developmental biology of each lesion, and potential interplay in the formation of an intermixed vascular neoplasm and vascular malformation. The roles of cellular origin, genetic susceptibility, favourable microenvironment, altered local gene expression and key regulatory pathways are reviewed. Our review supports angiography and genetic profiling in intermixed lesions to inform management strategies. Consideration should be given to multimodality therapeutic interventions as required, including microsurgical resection, stereotactic radiosurgery and further research to exploit emerging molecular targets.

Technical outcome of atlantoaxial transarticular screw fixation without supplementary posterior construct for rheumatoid arthritis.

BACKGROUND: transarticular screw (TAS) fixation without a supplementary posterior construct, even in rheumatoid arthritis (RA) patients, provides sufficient stability with acceptable clinical results. Here, we present our experience with 15 RA patients who underwent atlantoaxial (AA) TAS fixation without utilizing a supplementary posterior fusion. METHODS: To treat AA instability, all 15 RA patients underwent C1-C2 TAS fixation without a supplementary posterior construct. Patients were followed for at least 24 months. Pre- and postoperative sagittal measures of C1- C2, C2-C7, and C1-C7 angles, atlanto-dens interval (ADI), posterior atlanto-dens interval (PADI), and adjacent segment (i.e., C2-C3) anterior disc height (ADH) were retrospectively recorded from lateral X-ray imaging. The presence or absence of superior migration of the odontoid (SMO), cervical subaxial subluxation, C1-C2 bony fusion, screw pull-out, and screw breakage were also noted. RESULTS: There was little difference between the pre- and postoperative studies regarding angles measured. Following TAS fixation, the mean ADI shortened, and mean PADI lengthened. There was no difference in the mean measures of C2-C3 ADH. There was no evidence of SMO pre- or postoperatively. Two patients developed anterior subluxation at C5-C6; one of the two also developed anterior subluxation at C2-C3. All patients subsequently showed C1-C2 bony fusion without screw pull-out or breakage. CONCLUSION: In RA patients who have undergone C1-C2 TAS fixation, eliminating a supplementary posterior fusion resulted in adequate stability.

Ethical triage during the COVID-19 pandemic: a toolkit for neurosurgical resource allocation.

BACKGROUND: The COVID-19 pandemic confronts healthcare workers, including neurosurgeons, with difficult choices regarding which patients to treat. METHODS: In order to assist ethical triage, this article gives an overview of the main considerations and ethical principles relevant when allocating resources in times of scarcity. RESULTS: We discuss a framework employing four principles: prioritizing the worst off, maximizing benefits, treating patients equally, and promoting instrumental value. We furthermore discuss the role of age and comorbidity in triage and highlight some principles that may seem intuitive but should not form a basis for triage. CONCLUSIONS: This overview is presented on behalf of the European Association of Neurosurgical Societies and can be used as a toolkit for neurosurgeons faced with ethical dilemmas when triaging patients in times of scarcity.

A randomised controlled trial of multimodal physiotherapy versus advice for recent onset, painful cervical radiculopathy - the PACeR trial protocol.

BACKGROUND: A research gap exists for optimal management of cervical radiculopathy in the first 12 weeks and short term natural history of the condition is somewhat unclear, although thought to be favourable. The primary aim of this assessor blinded, superiority, 2 parallel group randomised controlled trial is to investigate the effects of a 4 week physiotherapy programme (6-8 sessions) of manual therapy, exercise and upper limb neural unloading tape, compared to a control of weekly phone advice; on disability, pain and selected biopsychosocial measures, in acute and sub-acute cervical radiculopathy patients. A secondary aim is to identify whether any baseline variables, symptom duration or group allocation can predict outcome. METHODS: Participants are recruited from GP referrals in an urban setting, from a neurosurgery non-urgent waiting list and from self-referral through Facebook advertising. Eligible participants (n = 64) are diagnosed with radiculopathy based on a clinical prediction rule and must have symptoms of unilateral, single level, radiculopathy for between 2 and 12 weeks, without having yet received physiotherapy. Random 1:1 group allocation (using variable block sizes), allocation concealment, blinded assessment and intention to treat analysis are being employed. Treatment is provided by clinical specialist physiotherapists in primary and secondary care settings. Outcomes are measured at baseline, 4 (primary endpoint) and 12 weeks. Participants' report of pain, disability and their rating of recovery is also recorded by telephone interview at 6 months. Statistical analysis of between group differences will be performed with ANOVAs and MANOVAs, and multivariable regression analysis will be undertaken to explore predictor variables. Ethical approval for this study has been received from the Beaumont Hospital and Irish College of General Practitioners Research Ethics Committees. The trial is registered at ClinicalTrials.gov (NCT02449200). DISCUSSION: An internal pilot study to test retention and recruitment strategies led to trial expansion and this is now a multi centre trial involving 5 clinical sites. TRIAL REGISTRATION: NCT02449200 . Registered 20/05/15.

Spinal Cord Ependymoma - Surgical Management and Outcome.

BACKGROUND: Ependymoma is a common primary neoplasm of the spinal cord and filum terminale. Patients with spinal ependymoma usually experience gradual symptoms due to slow progression of the tumor; thus, early diagnosis can be challenging to make. OBJECTIVE: The objective of this study was to report 5 years' experience in treating spinal intramedullary ependymomas and to illustrate the advantage of aggressive complete resection whenever possible. PATIENTS AND METHODS: Retrospective medical notes of all patients with spinal ependymoma treated surgically over a 5-year period between January 2003 and January 2008 were recorded. Clinical presentation, spinal level, extent of resection, and complications were recorded. A prolonged follow-up was documented. RESULTS: There were 20 patients - 11 males, and nine females -included in this study. Their median age was 48 years (range 3-75 years). In 18 patients, total gross resection was achieved. Subtotal resection was only possible in one patient due to surgical difficulty. One patient underwent biopsy and referred for further surgery and subsequently had total resection. CONCLUSIONS: Radical total resection is achievable in spinal ependymomas, with minimal resultant morbidity.

Evaluation of an increased strut porosity silicate-substituted calcium phosphate, SiCaP EP, as a synthetic bone graft substitute in spinal fusion surgery: a prospective, open-label study.

PURPOSE: Silicate-substituted calcium phosphate-enhanced porosity (SiCaP EP, Inductigraft™, Altapore) is a synthetic bone graft material with enhanced strut porosity of 31-47%. SiCaP EP remains to be fully clinically evaluated in patients undergoing instrumented posterolateral fusion (PLF) surgery. We conducted a prospective, open-label, non-randomised, multicentre clinical study to evaluate efficacy of SiCaP EP as bone grafting material in PLF surgery with instrumentation for treatment of spinal disorders. METHODS: Patients with degenerative disc disease, spondylolisthesis or spinal stenosis underwent PLF surgery with SiCaP EP. The primary endpoint was evaluated in the per protocol population (N = 102) as solid fusion at postoperative month 12 assessed using computed tomography scans, with motion assessed using flexion-extension radiographs. Clinical outcomes included the Oswestry Disability Index, 36-item short-form health survey for quality-of-life, visual analog scale for pain scores and neurological assessments. Adverse events were recorded. RESULTS: Successful fusion was achieved in 59/89 (66.3%) patients at month 6, 88/102 patients (86.3%) at month 12 (primary endpoint) and 87/96 (90.6%) patients at month 24. Disability and pain reduced following surgery. Quality-of-life improved and neurological function was maintained postoperatively. Forty-three (33.3%) of the 129 patients who underwent surgery experienced adverse events; back pain was most frequent (n = 10); nine and 14 patients experienced serious adverse events judged related to device and procedure, respectively. CONCLUSIONS: Enhanced strut porosity SiCaP EP provided high (month 12: 86.3%) spinal fusion success rates in PLF surgery. Fusion success was associated with improved clinical outcomes in patients within 12 months, relative to baseline. CLINICALTRIALS. GOV IDENTIFIER: NCT01452022 These slides can be retrieved under Electronic Supplementary Material.

Geographic variations in clinical presentation and outcomes of decompressive surgery in patients with symptomatic degenerative cervical myelopathy: analysis of a prospective, international multicenter cohort study of 757 patients.

BACKGROUND CONTEXT: Degenerative cervical myelopathy (DCM) is a progressive degenerative spine disease and the most common cause of spinal cord impairment in adults worldwide. Few studies have reported on regional variations in demographics, clinical presentation, disease causation, and surgical effectiveness. PURPOSE: The objective of this study was to evaluate differences in demographics, causative pathology, management strategies, surgical outcomes, length of hospital stay, and complications across four geographic regions. STUDY DESIGN/SETTING: This is a multicenter international prospective cohort study. PATIENT SAMPLE: This study includes a total of 757 symptomatic patients with DCM undergoing surgical decompression of the cervical spine. OUTCOME MEASURES: The outcome measures are the Neck Disability Index (NDI), the Short Form 36 version 2 (SF-36v2), the modified Japanese Orthopaedic Association (mJOA) scale, and the Nurick grade. MATERIALS AND METHODS: The baseline characteristics, disease causation, surgical approaches, and outcomes at 12 and 24 months were compared among four regions: Europe, Asia Pacific, Latin America, and North America. RESULTS: Patients from Europe and North America were, on average, older than those from Latin America and Asia Pacific (p=.0055). Patients from Latin America had a significantly longer duration of symptoms than those from the other three regions (p<.0001). The most frequent causes of myelopathy were spondylosis and disc herniation. Ossification of the posterior longitudinal ligament was most prevalent in Asia Pacific (35.33%) and in Europe (31.75%), and hypertrophy of the ligamentum flavum was most prevalent in Latin America (61.25%). Surgical approaches varied by region; the majority of cases in Europe (71.43%), Asia Pacific (60.67%), and North America (59.10%) were managed anteriorly, whereas the posterior approach was more common in Latin America (66.25%). At the 24-month follow-up, patients from North America and Asia Pacific exhibited greater improvements in mJOA and Nurick scores than those from Europe and Latin America. Patients from Asia Pacific and Latin America demonstrated the most improvement on the NDI and SF-36v2 PCS. The longest duration of hospital stay was in Asia Pacific (14.16 days), and the highest rate of complications (34.9%) was reported in Europe. CONCLUSIONS: Regional differences in demographics, causation, and surgical approaches are significant for patients with DCM. Despite these variations, surgical decompression for DCM appears effective in all regions. Observed differences in the extent of postoperative improvements among the regions should encourage the standardization of care across centers and the development of international guidelines for the management of DCM.

Adjuvant analgesics in spinal surgery.

Peri- and postoperative pain control can present a challenge to any doctor, particularly in the setting of spinal surgery. The use of adjuvant pain agents and multimodal analgesia is changing the face of modern anaesthesia and offering clinicians more avenues to control perioperative pain. This article discusses the use of adjuvant medications and some of the evidence surrounding their use in spinal surgery.

Gross total resection rates of grade II/III intramedullary ependymomas using the surgical strategy of en-bloc resection without intra-operative neurophysiological monitoring.

INTRODUCTION: Grade II and III intramedullary ependymomas [IME] are circumscribed with a plane of cleavage that should facilitate high gross total resection rates (GTR). Gross total resection of grade II/III IME is superior to subtotal resection (STR) and radiotherapy (RTx) for progression-free and overall survival. We sought to compare our GTR with other series that have utilised standard intraoperative monitoring techniques and we explored factors that may influence rates of resection. MATERIALS AND METHODS: Database search and retrospective chart and radiological review of all grade II or III spinal ependymomas over a 10-year period from the senior authors practice. Comprehensive PubMed search to identify similar series that identified histology, McCormick Function scores (MCC) preoperatively and post-operatively, surgical strategy and use of intraoperative monitoring. Standard statistical analysis was performed. RESULTS: Seventeen patients were identified: 16 grade II and one grade 3. GTR was 94.12%. Factors that correlated with a decline in MCC were longitudinal extension of the tumour (p = 0.0238) and presentation with motor signs and symptoms (p = 0.0223). There was no statistical difference between preoperative factors that influence post-operative outcomes in the current study when compared with other published series. There was no statistical difference between preoperative and postoperative MCC scores between our series and other published series. DISCUSSION: The current series with a GTR of 94.12% compares favourably with other published series with GTRs of 55.8-84% with no significant difference in functional outcomes. Series with low GTRs should examine their operative strategy or false-positive alarm rates which may lead to higher STRs. This series should be viewed as a unique opportunity to benchmark GTRs of circumscribed intramedullary tumours.

A global perspective on the outcomes of surgical decompression in patients with cervical spondylotic myelopathy: results from the prospective multicenter AOSpine international study on 479 patients.

STUDY DESIGN: Prospective, multicenter international cohort. OBJECTIVE: To evaluate outcomes of surgical decompression for cervical spondylotic myelopathy (CSM) at a global level. SUMMARY OF BACKGROUND DATA: CSM is a degenerative spine disease and the most common cause of spinal cord dysfunction worldwide. Surgery is increasingly recommended as the preferred treatment strategy for CSM to improve neurological and functional status and quality of life. The outcomes of surgical intervention for CSM have never been evaluated at an international level. METHODS: Between October 2007 and January 2011, 479 symptomatic patients with image evidence of CSM were enrolled in the prospective, multicenter AOSpine CSM-International study from 16 global sites. Preoperative and postoperative clinical status, functional impairment, and quality of life were evaluated using the modified Japanese Orthopaedic Assessment Scale, Nurick Scale, Neck Disability Index, and Short-Form-36v2. Preoperative and 12- and 24-month postoperative outcomes were compared using mixed-model analysis of covariance for repeated measurements. RESULTS: The study cohort consisted of 310 males and 169 females, with a mean age of 56.37 ± 11.91 years. There were significant differences in age, etiology, and surgical approaches between the regions. At 24 months postoperatively, the mean modified Japanese Orthopaedic Assessment Scale score improved from 12.50 (95% confidence interval [CI], 12.24-12.76) to 14.90 (95% CI, 14.64-15.16); the Neck Disability Index improved from 36.38 (95% CI, 34.33-38.43) to 23.20 (95% CI, 21.24-25.15); and the SF36v2 Physical Component Score and Mental Composite Score improved from 34.28 (95% CI, 33.46-35.10) to 40.76 (95% CI, 39.71-41.81) and 39.45 (95% CI, 38.25-40.64) to 46.24 (95% CI, 44.94-47.55), respectively. The rate of neurological complications was 3.13%. CONCLUSION: Surgical decompression for CSM is safe and results in improved functional status and quality of life in patients around the world, irrespective of differences in medical systems and sociocultural determinants of health. LEVEL OF EVIDENCE: 3.

Three-dimensional gait analysis outcomes at 1 year following decompressive surgery for cervical spondylotic myelopathy.

PURPOSE: Gait impairment is an important feature of cervical sponydylotic myelopathy (CSM) as it can have a detrimental effect on function and quality of life. The aim of this study was to measure changes in gait in people with CSM following surgical decompression. METHODS: Thirteen participants with clinical and radiological evidence of CSM underwent three-dimensional gait analysis, using a full lower limb kinematic, kinetic and electromyography protocol, before and 12 months after decompressive surgery. RESULTS: No significant post-operative changes were detected in temporal-spatial or kinematic parameters. Kinetic data showed significant improvements in knee power absorption [mean improvement, 0.42 watts per kilogram (W/kg)], ankle plantarflexor moment (0.1 Nm/kg) and ankle power generation (0.55 W/kg). Electromyography showed a 4.7 % increase in tibialis anterior activation time. CONCLUSIONS: These findings indicate that improvement in locomotor function can be achieved after surgery. Future studies should explore the potential for further recovery of gait through targeted neuro-rehabilitation.

Electromyographic characteristics of gait impairment in cervical spondylotic myelopathy.

AIM: Gait impairment in cervical spondylotic myelopathy (CSM) is characterised by a number of kinematic and kinetic abnormalities. Surface electromyography (EMG) can evaluate the contributions of individual muscles to a movement pattern and provide insight into the underlying impairments that characterise an abnormal gait. This study aimed to analyse EMG signals from major lower limb muscles in people with CSM and healthy controls during gait. METHODS: Sixteen people with radiologically confirmed CSM and 16 matched healthy controls participated in gait analysis. Surface EMG was recorded during walking from four lower limb muscles bilaterally. The timing of muscle activation, relative amplitudes of each burst of activity and baseline activation during gait, and the muscles' responses to lengthening as a measure of spasticity were compared using previously validated methods of EMG analysis. RESULTS: Compared to healthy controls, people with CSM had prolonged duration of activation of biceps femoris (12.5% longer) and tibialis anterior (12.4%), prolonged co-activation of rectus femoris and biceps femoris (5.14%), and impaired scaling of the amplitude of rectus femoris and biceps femoris. Muscle activation in response to lengthening was similar between groups. CONCLUSION: The results provide evidence for paresis as a contributory factor to gait impairment in CSM, indicated by impaired amplitude and the need for proximal co-activation to compensate for lack of distal power generation. Poor proprioception may have contributed to prolonged activation of tibialis anterior. Analysis of muscle responses to lengthening suggested that spasticity was not an important contributor. These findings have implications for the assessment and rehabilitation of gait impairment in CSM.

The Subaxial Cervical Spine Injury Classification System: an external agreement validation study.

BACKGROUND CONTEXT: In 2007, the Subaxial Cervical Spine Injury Classification (SLIC) system was introduced demonstrating moderate reliability in an internal validation study. PURPOSE: To assess the agreement on the SLIC system using clinical data from a spinal trauma population and whether the SLIC treatment algorithm outcome improved agreement on treatment decisions among surgeons. STUDY DESIGN: An external classification validation study. PATIENT SAMPLE: Twelve spinal surgeons (five consultants and seven fellows) assessed 51 randomly selected cases. OUTCOME MEASURES: Raw agreement, Fleiss kappa, and intraclass correlation coefficient statistics were used for reliability analysis. Majority rules and latent class modeling were used for accuracy analysis. METHODS: Fifty-one randomly selected cases with significant injuries of the cervical spine from a prospective consecutive series of trauma patients were assessed using the SLIC system. Neurologic details, plain radiographs, and computed tomography scans were available for all cases as well as magnetic resonance imaging in 21 cases (41%). No funds were received in support of this study. The authors have no conflict of interest in the subject of this article. RESULTS: The inter-rater agreement on the most severely affected level of injury was strong (κ=0.76). The agreement on the morphologic injury characteristics was poor (κ=0.29) and agreement on the integrity of the discoligamentous complex was average (κ=0.46). The inter-rater agreement on the treatment verdict after the total SLIC injury severity score was slightly lower than the surgeons' agreement on personal treatment preference (κ=0.55 vs. κ=0.63). Latent class analysis was not converging and did not present accurate estimations of the true classification categories. Based on these findings, no second survey for testing intrarater agreement was performed. CONCLUSIONS: We found poor agreement on the morphologic injury characteristics of the SLIC system, and its treatment algorithm showed no improved agreement on treatment decisions among surgeons. The authors discuss that the reproducibility of the SLIC system is likely to improve when unambiguous true morphologic injury characteristics are being implemented.