Michael G Fehlings

Michael G Fehlings
University of Toronto | U of T · Division of Neurosurgery

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1,677
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Publications

Publications (1,677)
Article
IntroductionIn vivomicroscopy contributes to a deeper under-standing of pathophysiology and potential therapies after experimentalSpinal Cord Injury (SCI). An implanted spinal window chamber en-ables longitudinal imaging without the necessity for repeated surgery.ObjectivesWe present an implanted spinal window chamber forchronicin vivoimaging after...
Article
Introduction:The disruption of the Blood-Spinal-Cord-Barrier(BSCB) is a leading pathophysiology in traumatic Spinal Cord Injury(SCI), and its restitution plays a crucial role in spinal cord regenera-tion. A deeper understanding of the pathophysiology and its time-frame will enhance the search for regenerative therapies.Objectives:We characterize BS...
Article
The outcomes of cervical incomplete spinal cord injury (SCI) are heterogeneous. This study sought to dissociate subgroups of cervical incomplete SCI patients with distinct longitudinal temporal profiles of recovery in upper limb motor function. Patients with cervical incomplete SCI (AIS B-D; C1-C8) were identified from 4 prospective, multi-center S...
Article
Spinal cord injury (SCI) elicits a cascade of degenerative events including cell death, axonal degeneration, and the upregulation of inhibitory molecules which limit repair. Repulsive guidance molecule A (RGMa) is an axon growth inhibitor which is also involved in neuronal cell death and differentiation. SCI causes upregulation of RGMa in the injur...
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Study design: Modified DELPHI Consensus Process. Objective: To agree a single unifying term and definition. Globally, cervical myelopathy caused by degenerative changes to the spine is known by over 11 different names. This inconsistency contributes to many clinical and research challenges, including a lack of awareness. Method: AO Spine RECOD...
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Systemic assessment is a pillar in the neurological, oncological, mechanical, and systemic (NOMS) decision-making framework for the treatment of patients with spinal metastatic disease. Despite this importance, emerging evidence relating systemic considerations to clinical outcomes following surgery for spinal metastatic disease has not been compre...
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Application of deep learning methods to transcriptomic data has the potential to enhance the accuracy and efficiency of tissue classification and cell state identification. Herein, we developed a multitask deep learning model for tissue classification combining publicly available whole transcriptomic (RNA-seq) datasets of non-neoplastic, neoplastic...
Article
The strides that have been achieved in the realm of spinal cord injury (SCI) management are remarkable. It is likely that 90 percent of what has been recognized to date about SCI pathophysiology and treatment has emerged over the past three decades. As such, the field of SCI research has experienced an enormous evolution with preclinical studies si...
Article
The Graded Redefined Assessment of Strength, Sensibility, and Prehension Version 1 (GRASSP v1) is a validated measure of upper extremity impairment shown to be sensitive and responsive for traumatic cervical spinal cord injury (SCI) in both North American (NA) and European (EU) cohorts. The minimal clinically important difference (MCID) is the quan...
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Introduction Progress in degenerative cervical myelopathy (DCM) is hindered by inconsistent measurement and reporting. This impedes data aggregation and outcome comparison across studies. This limitation can be reversed by developing a core measurement set (CMS) for DCM research. Previously, the AO Spine Research Objectives and Common Data Elements...
Article
Introduction Spinal arachnoid cysts (SACs) are rare lesions with challenging and controversial management. Research question We analyzed our experiences from a case series and provide a systematic review to determine 1) Demographic and clinical features of SACs, 2) Optimal imaging for diagnosis and operative planning, 3) Optimal management of SACs...
Article
Background: Despite a higher prevalence of traumatic spinal cord injury (TSCI) amongst Canadian Indigenous peoples, there is a paucity of studies focused on Indigenous TSCI. We present the first Canada-wide study comparing TSCI amongst Canadian Indigenous and non-Indigenous peoples. Methods: This study is a retrospective analysis of prospectively-c...
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Background: Proper utilization of high-quality clinical practice guidelines (CPGs) eliminates the dependence of patients' outcomes on the ability and knowledge of "individual" health care providers and reduces unwarranted variation in care. The aim of this study was to adapt/adopt two CPGs for pharmacologic management of acute spinal cord injury (...
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Transplantation of Neural Stem/Progenitor Cells (NPCs) is a promising regenerative strategy to promote neural repair following injury and degeneration because of the ability of these cells to proliferate, migrate, and integrate with the host tissue. Precise in vitro control of NPC proliferation without compromising multipotency and differentiation...
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Spinal cord injury is a severely disabling neurological condition leading to impaired mobility, pain, and autonomic dysfunction. Most often, a single traumatic event, such as a traffic or recreational accident, leads to primary spinal cord damage through compression and laceration, followed by secondary damage consisting of inflammation and ischaem...
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Studies on outcomes after four-level anterior cervical discectomy and fusion (ACDF) are limited in the literature. The purpose of this study was to report on clinical outcomes and revision rates following four-level ACDF. Patients operated with four-level ACDF were identified in a prospectively accrued single institution database. Outcome scores in...
Article
Study Design Questionnaire-based survey. Objectives Surgical site infection (SSI) is a common complication in spine surgery but universal guidelines for SSI prevention are lacking. The objectives of this study are to depict a global status quo on implemented prevention strategies in spine surgery, common themes of practice and determine key areas...
Article
Human-induced pluripotent stem cell-derived neural stem/progenitor cell (hiPSC-NS/PCs) transplantation during the acute phase of spinal cord injury (SCI) is not effective due to the inflammatory response occurring immediately after SCI, which negatively impacts transplanted cell survival. Therefore, we chose to study the powerful chemoattractant co...
Article
Now in its centennial year since inauguration, the Department of Surgery at the University of Toronto lays claim to more than 500 faculty, 270 residents, and 250 clinical fellows. There are 7 direct entry residency training programs, and 4 subspecialty programs accredited by the Royal College of Physicians and Surgeons of Canada. There have been 10...
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Study Design Literature Review (Narrative). Objective To introduce the number 10 research priority for Degenerative Cervical Myelopathy: Individualizing Surgery. Methods This article summarizes the current recommendations and indications for surgery, including how known prognostic factors such as injury time, age, disease severity, and associated...
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Study Design Literature Review (Narrative) Objective To propose a new framework, to support the investigation and understanding of the pathobiology of DCM, AO Spine RECODE-DCM research priority number 5. Methods Degenerative cervical myelopathy is a common and disabling spinal cord disorder. In this perspective, we review key knowledge gaps betwe...
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Study Design Narrative review. Objectives To discuss the importance of establishing diagnostic criteria in Degenerative Cervical Myelopathy (DCM), including factors that must be taken into account and challenges that must be overcome in this process. Methods Literature review summarising current evidence of establishing diagnostic criteria for DC...
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Study Design Narrative review. Objective Degenerative cervical myelopathy is one of the most frequent impairments of the spinal cord encountered internationally in adults. Currently, surgical decompression is the recommended treatment for people with DCM (PwCM) presenting with moderate to severe symptoms or neurological deficits. However, despite...
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Study Design Overview of the methods used for a James Lind Alliance (JLA) Priority Setting Partnership (PSP). Objectives The objectives of this article are to (i) provide a brief overview of the JLA—facilitated PSP process; (ii) outline how research uncertainties were initially processed in the AO Spine RECODE-DCM PSP; and (iii) delineate the meth...
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Study design Narrative review. Objectives To provide an overview of contemporary therapies for the James Lind Alliance priority setting partnership for degenerative cervical myelopathy (DCM) question: ‘Can novel therapies, including stem-cell, gene, pharmacological and neuroprotective therapies, be identified to improve the health and wellbeing of...
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Study Design Literature Review (Narrative) Objective To introduce the number one research priority for Degenerative Cervical Myelopathy (DCM): Raising Awareness. Methods Raising awareness has been recognized by AO Spine RECODE-DCM as the number one research priority. This article reviews the evidence that awareness is low, the potential drivers,...
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Study Design Narrative review. Objectives To discuss the current understanding of the natural history of degenerative cervical myelopathy (DCM). Methods Literature review summarizing current evidence pertaining to the natural history and risk factors of DCM. Results DCM is a common condition in which progressive arthritic disease of the cervical...
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Study Design Literature Review (Narrative). Objective To contextualize AO Spine RECODE-DCM research priority number 5: What is the socio-economic impact of DCM? (The financial impact of living with DCM to the individual, their supporters, and society as a whole). Methods In this review, we introduce the methodology of health-economic investigatio...
Article
Objective: Patients presenting with neurological deficit secondary to metastatic epidural spinal cord compression (MESCC) are often treated with surgery in combination with high dose corticosteroids. Despite steroids being commonly used, the evidence regarding the effect of corticosteroids on patient outcomes is limited. The objective of this stud...
Article
Study Design Narrative Review. Objectives The objective of this review is to provide a stepwise approach to the assessment of patients with potential symptoms of degenerative cervical myelopathy (DCM). Methods N/A Results DCM is an overarching term used to describe progressive compression of the cervical spinal cord by age-related changes to the...
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Full-text available
Objectives To evaluate the measurement properties of outcome measures currently used in the assessment of degenerative cervical myelopathy (DCM) for clinical research. Design Systematic review Data sources MEDLINE and EMBASE were searched through 4 August 2020. Eligibility criteria Primary clinical research published in English and whose primary...
Article
Ependymomas are rare central nervous system tumours that can arise in the brain’s supratentorial region or posterior fossa, or in the spinal cord. In 1924, Percival Bailey published the first comprehensive study of ependymomas. Since then, and especially over the past 10 years, our understanding of ependymomas has grown exponentially. In this Revie...
Article
Patients with motor complete traumatic spinal cord injury (tSCI) have a low potential to recover ambulation. Motor level recovery, adjacent to the level of injury, could influence functional independency. This study addresses whether surgical timing influences motor level recovery in patients with sensorimotor complete (AIS A) and motor complete se...
Chapter
Spinal cord injury introduces complex pathophysiological consequences that contribute to devastating behavioral outcomes. In recent years, induced pluripotent stem cell (iPSC)-based technologies have emerged as tools that can advance cell-based therapeutics and disease modeling for SCI. iPSCs can be used as the starting source for a number of poten...
Chapter
This chapter reviews the impact of surgical timing on neurological recovery in traumatic spinal cord injury (tSCI) patients. To put the effect of surgery into perspective, a brief summary of spontaneous neurological recovery for different spinal levels of tSCI is described. Subsequently, the type of surgical intervention to achieve decompression, a...
Chapter
Spinal cord injury (SCI) is associated with significant physical and psychological morbidity among patients and carries major economic ramifications to both individuals and health-care systems. The ability to mitigate the damage caused by acute SCI and impact the natural history of this condition with pharmacotherapy has been a naturally enticing,...
Chapter
Traumatic spinal cord injury (tSCI) is a devastating event with the potential to profoundly impair patients' sensory, motor, and autonomic functions. In addition to the primary injury, tSCI patients also suffer from a range of complications that impact patient outcome and quality of life. It is important for clinicians to be aware of the complicati...
Chapter
The epidemiology, pathophysiology, and guidelines for clinical management of spinal cord injury are reviewed here. Aspects of management covered include operative versus nonoperative approaches, surgical timing, immobilization, neurological assessment, hemodynamic regulation, and pharmacological management. The roles of vascular disruption, ionic i...
Chapter
Central cord syndrome (CCS) is the most common incomplete spinal cord injury, classically characterized by disproportionately greater upper than lower limb weakness. CCS often occurs in the elderly patient with spinal stenosis after a cervical hyperextension injury due to low-velocity trauma. CCS is especially relevant today due to the aging popula...
Chapter
Spinal cord injury (SCI) is a devastating, life-changing neurotrauma with a high-disease burden. It leads to instant and permanent neurological impairment below the injury level due to disruption of afferent and efferent neural pathways. SCI is often associated with increased morbidity and premature mortality, leading to strain of the physical, emo...
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The field of spinal cord injury (SCI) research has experienced an immense evolution over the past decades whereby results from preclinical studies have significantly facilitated our understanding of pathophysiologic mechanisms underlying SCI, including causes of heterogeneity in outcomes among patients. Notably, in detail knowledge of the pathobiol...
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Understanding the functional anatomy and biomechanics of the spine is essential in the management of spinal trauma and spinal cord injury. Moreover, insight into the complexity of spinal tracts and level-specific differences in spinal cord anatomy is the foundation of understanding disease processes and developing novel therapies for spinal cord in...
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This chapter will provide an overview of various cellular regenerative therapies currently being implemented in clinical trials for the treatment of spinal cord injury (SCI). These treatments involve stem cell transplantation of various neural cell subtypes that aim to help replenish the loss of cells at the site of injury, thus aiming to improve t...
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This chapter discusses five main areas of controversy in the management of spine trauma: optimal management of A3/A4 thoracolumbar fractures, minimally invasive surgery in spine trauma, operative management of C2 peg fractures in the elderly, the timing of surgery in central cord syndrome, and the role of magnetic resonance imaging in the managemen...
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Neuroprotective therapies in the setting of spinal cord injury offer the advantage of limiting secondary damage, which is likely more effective than replacing damaged or lost cells. The pathophysiology of secondary injury has biochemical, physical, and cellular features. Neuroprotective approaches, as shown by preclinical studies, may address one o...
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This chapter examines the economic impact of traumatic spinal cord injury from the individual level to the societal perspective. It starts with a brief review of the main concepts in health economics that are applicable to the field of traumatic spinal cord injury. It subsequently describes the economic burden of traumatic spinal cord injury in the...
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This chapter will provide an overview of the current noncellular regenerative therapies used in clinical trials as part of treating spinal cord injury (SCI). These methods include the use of antibodies, growth factors, minerals, drugs, biomaterials, and electrical stimulation, which aim to assist the endogenous regenerative circuitry to promote rep...
Chapter
Spinal cord injury (SCI) can be characterized as traumatic (tSCI) or nontraumatic chronic in nature, the latter mostly seen in the form of degenerative cervical myelopathy (DCM). Both conditions share several pathophysiological changes in their respective disease processes. Traditional imaging modalities such as X-rays, computed tomography, and con...
Article
Traumatic spinal cord injuries (SCIs) have devastating physical, social, and financial consequences for both patients and their families. SCIs most frequently occur at the cervical spine level, and these injuries are particularly prone to causing debilitating functional impairments. Unfortunately, no effective neuroregenerative therapeutic approach...
Chapter
Traumatic spinal cord injury (SCI) is a multifaceted condition, which hinders the patient’s mobility, independence, and quality of life. Following injury, vascular damage is a key mediator in a cascade of secondary pathologies that further exacerbates tissue loss and functional deficits. In the noninjured spinal cord, the spinal vasculature is cruc...
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Full-text available
Study design Narrative Review. Objective To (i) discuss why assessment and monitoring of disease progression is critical in Degenerative cervical myelopathy (DCM); (ii) outline the important features of an ideal assessment tool and (iii) discuss current and novel strategies for detecting subtle deterioration in DCM. Methods Literature review Res...
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Introduction Traumatic Spinal Cord Injury (SCI) is one of the leading causes of disability in the world. Treatment is limited to supportive care and no curative therapy exists. Experimental research to understand the complex pathophysiology and potential mediators of spinal cord regeneration is essential to develop innovative translational therapie...
Article
Study Design Systematic review. Objective Ehlers-Danlos Syndrome (EDS) comprises a spectrum of connective tissue disorders, which may be associated with cranio-cervical instability (CCI). There is a lack of consensus on diagnostic imaging parameters, indications, and outcomes of surgical treatment. Methods This systematic review analyses the lite...
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Study Design Survey. Introduction AO Spine Research Objectives and Common Data Elements for Degenerative Cervical Myelopathy (RECODE-DCM) is an international initiative that aims to accelerate knowledge discovery and improve outcomes by developing a consensus framework for research. This includes defining the top research priorities, an index term...
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Neural progenitor cell (NPC) transplants are a promising therapy for treating spinal cord injury (SCI), however, their long-term role after engraftment and the relative contribution to ongoing functional recovery remains a key knowledge gap. Selective human cell ablation techniques, currently being developed to improve the safety of progenitor cell...
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The astroglial scar is a defining hallmark of secondary pathology following central nervous system (CNS) injury that, despite its role in limiting tissue damage, presents a significant barrier to neuroregeneration. Neural progenitor cell (NPC) therapies for tissue repair and regeneration have demonstrated favorable outcomes, the effects of which ar...
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Despite the debilitating consequences following traumatic spinal cord injury (SCI), there is a lack of safe and effective therapeutics in the clinic. The species-specific responses to SCI present major challenges and opportunities for the clinical translation of biomolecular and pharmacological interventions. Recent transcriptional analyses in prec...
Article
Objective: Degenerative cervical myelopathy (DCM) is a major global cause of spinal cord dysfunction. Surgical treatment is considered a safe and effective way to improve functional outcome, although information about long-term functional outcome remains scarce despite increasing longevity. The objective of this study was to describe functional ou...
Article
Full-text available
Study Design Narrative review. Objective The current review aimed to describe the role of existing techniques and emerging methods of imaging and electrophysiology for the management of degenerative cervical myelopathy (DCM), a common and often progressive condition that causes spinal cord dysfunction and significant morbidity globally. Methods A...
Preprint
Full-text available
Introduction: Progress in degenerative cervical myelopathy (DCM) is hindered by inconsistent measurement and reporting of outcomes. This can, for example, impede the aggregation of data and comparison of outcomes between studies. This limitation can be reversed by developing a core measurement set (CMS) for use in DCM research. Previously, the AO S...
Article
Full-text available
IntroductionNeurologic complications after complex adult spinal deformity (ASD) surgery are important, yet outcomes are heterogeneously reported, and long-term follow-up of actual lower extremity motor function is unknown.Objective To prospectively evaluate lower extremity motor function scores (LEMS) before and at 5 years after surgical correction...
Article
Background: There is significant heterogeneity in neurological recovery after complete (ASIA A) traumatic spinal cord injury (tSCI). Neurological recovery is often associated with a conversion to a higher letter grade of the American Spinal Injury Association’s impairment scale (ASIA). The mechanism of injury (MOI) may play a significant role in th...
Article
Background: Despite growing evidence for early surgical decompression for traumatic cervical spinal cord injury(tCSCI) patients, controversy surrounds the efficacy of early surgical decompression on patients with a complete (ASIA A) cervical injury. Methods: Patients with ASIA A cervical tCSCI were isolated from 4 prospective, multi-center datasets...
Article
Background: Neurotrauma accounts for over 24 000 hospitalizations annually in Canada. Among those affected, Indigenous peoples are disproportionately impacted. The goal of this scoping review is to identify factors underlying these disparities. Methods: A scoping review was conducted to collect papers pertaining to neurotrauma in Indigenous populat...
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Full-text available
The clinical indications and added value of obtaining MRI in the acute phase of spinal cord injury (SCI) remain controversial. This review aims to critically evaluate evidence regarding the role of MRI to influence decision-making and outcomes in acute SCI. A systematic review and meta-analysis were performed according to PRISMA methodology to iden...