1
|
Debenham MIB, Franz CK, Berger MJ. Neuromuscular consequences of spinal cord injury: New mechanistic insights and clinical considerations. Muscle Nerve 2024; 70:12-27. [PMID: 38477416 DOI: 10.1002/mus.28070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 02/13/2024] [Accepted: 02/17/2024] [Indexed: 03/14/2024]
Abstract
The spinal cord facilitates communication between the brain and the body, containing intrinsic systems that work with lower motor neurons (LMNs) to manage movement. Spinal cord injuries (SCIs) can lead to partial paralysis and dysfunctions in muscles below the injury. While traditionally this paralysis has been attributed to disruptions in the corticospinal tract, a growing body of work demonstrates LMN damage is a factor. Motor units, comprising the LMN and the muscle fibers with which they connect, are essential for voluntary movement. Our understanding of their changes post-SCI is still emerging, but the health of motor units is vital, especially when considering innovative SCI treatments like nerve transfer surgery. This review seeks to collate current literature on how SCI impact motor units and explore neuromuscular clinical implications and treatment avenues. SCI reduced motor unit number estimates, and surviving motor units had impaired signal transmission at the neuromuscular junction, force-generating capacity, and excitability, which have the potential to recover chronically, yet the underlaying mechanisms are unclear. Furthermore, electrodiagnostic evaluations can aid in assessing the health lower and upper motor neurons, identify suitable targets for nerve transfer surgeries, and detect patients with time sensitive injuries. Lastly, many electrodiagnostic abnormalities occur in both chronic and acute SCI, yet factors contributing to these abnormalities are unknown. Future studies are required to determine how motor units adapt following SCI and the clinical implications of these adaptations.
Collapse
Affiliation(s)
- Mathew I B Debenham
- International Collaboration on Repair Discoveries (ICORD), Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- Division of Physical Medicine & Rehabilitation, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Colin K Franz
- Biologics Laboratory, Shirley Ryan AbilityLab, Chicago, Illinois, USA
- Physical Medicine and Rehabilitation, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
- Ken & Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Michael J Berger
- International Collaboration on Repair Discoveries (ICORD), Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- Division of Physical Medicine & Rehabilitation, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| |
Collapse
|
2
|
Berger MJ, Adewuyi AA, Doherty C, Hanlan AK, Morin C, O'Connor R, Sharma R, Sproule S, Swong KN, Wu H, Franz CK, Brown E. Segmental infralesional pathological spontaneous activity in subacute traumatic spinal cord injury. Muscle Nerve 2024; 69:403-408. [PMID: 38294062 DOI: 10.1002/mus.28053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 01/13/2024] [Accepted: 01/21/2024] [Indexed: 02/01/2024]
Abstract
INTRODUCTION/AIMS There is a dearth of knowledge regarding the status of infralesional lower motor neurons (LMNs) in individuals with traumatic cervical spinal cord injury (SCI), yet there is a growing need to understand how the spinal lesion impacts LMNs caudal to the lesion epicenter, especially in the context of nerve transfer surgery to restore several key upper limb functions. Our objective was to determine the frequency of pathological spontaneous activity (PSA) at, and below, the level of spinal injury, to gain an understanding of LMN health below the spinal lesion. METHODS Ninety-one limbs in 57 individuals (53 males, mean age = 44.4 ± 16.9 years, mean duration from injury = 3.4 ± 1.4 months, 32 with motor complete injuries), were analyzed. Analysis was stratified by injury level as (1) C4 and above, (2) C5, and (3) C6-7. Needle electromyography was performed on representative muscles innervated by the C5-6, C6-7, C7-8, and C8-T1 nerve roots. PSA was dichotomized as present or absent. Data were pooled for the most caudal infralesional segment (C8-T1). RESULTS A high frequency of PSA was seen in all infralesional segments. The pooled frequency of PSA for all injury levels at C8-T1 was 68.7% of the limbs tested. There was also evidence of PSA at the rostral border of the neurological level of injury, with 58.3% of C5-6 muscles in those with C5-level injuries. DISCUSSION These data support a high prevalence of infralesional LMN abnormalities following SCI, which has implications to nerve transfer candidacy, timing of the intervention, and donor nerve options.
Collapse
Affiliation(s)
- Michael J Berger
- International Collaboration on Repair Discoveries (ICORD), Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- Division of Physical Medicine & Rehabilitation, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- Vancouver Coastal Health Authority, Vancouver, British Columbia, Canada
| | - Adenike A Adewuyi
- Regenerative Neurorehabilitation Laboratory, Shirley Ryan AbilityLab, Chicago, Illinois, USA
- Physical Medicine and Rehabilitation, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
- Ken & Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Christopher Doherty
- Vancouver Coastal Health Authority, Vancouver, British Columbia, Canada
- Division of Plastic Surgery, Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada
| | - Amy K Hanlan
- Division of Physical Medicine & Rehabilitation, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- Vancouver Coastal Health Authority, Vancouver, British Columbia, Canada
| | - Cynthia Morin
- Division of Plastic Surgery, Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada
| | - Russ O'Connor
- Division of Physical Medicine & Rehabilitation, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- Vancouver Coastal Health Authority, Vancouver, British Columbia, Canada
| | - Radhika Sharma
- Regenerative Neurorehabilitation Laboratory, Shirley Ryan AbilityLab, Chicago, Illinois, USA
- Physical Medicine and Rehabilitation, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Shannon Sproule
- Division of Plastic Surgery, Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kevin N Swong
- Department of Neurological Surgery, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
| | - Harvey Wu
- International Collaboration on Repair Discoveries (ICORD), Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Colin K Franz
- Regenerative Neurorehabilitation Laboratory, Shirley Ryan AbilityLab, Chicago, Illinois, USA
- Physical Medicine and Rehabilitation, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
- Ken & Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Erin Brown
- Vancouver Coastal Health Authority, Vancouver, British Columbia, Canada
- Division of Plastic Surgery, Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada
| |
Collapse
|
3
|
Berger MJ, Dengler J, Westman A, Curt A, Schubert M, Abel R, Weidner N, Röhrich F, Fox IK. Nerve Transfer After Cervical Spinal Cord Injury: Who Has a "Time Sensitive" Injury Based on Electrodiagnostic Findings? Arch Phys Med Rehabil 2024; 105:682-689. [PMID: 37979641 DOI: 10.1016/j.apmr.2023.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 11/06/2023] [Accepted: 11/07/2023] [Indexed: 11/20/2023]
Abstract
OBJECTIVE To use the ulnar compound muscle action potential (CMAP) to abductor digiti minimi (ADM) to identify the proportion of individuals with cervical spinal cord injury (SCI) who have lower motor neuron (LMN) abnormalities involving the C8-T1 spinal nerve roots, within 3-6 months, and thus may influence the response to nerve transfer surgery. DESIGN Retrospective analysis of prospectively collected data. Data were analyzed from European Multicenter Study About SCI database. SETTING Multi-center, academic hospitals. PARTICIPANTS We included 79 subjects (age=41.4±17.7, range:16-75; 59 men; N=79), who were classified as cervical level injuries 2 weeks after injury and who had manual muscle strength examinations that would warrant consideration for nerve transfer (C5≥4, C8<3). INTERVENTIONS None. MAIN OUTCOME MEASURES The ulnar nerve CMAP amplitude to ADM was used as a proxy measure for C8-T1 spinal segment health. CMAP amplitude was stratified into very abnormal (<1.0 mV), sub-normal (1.0-5.9 mV), and normal (>6.0 mV). Analysis took place at 3 (n=148 limbs) and 6 months (n=145 limbs). RESULTS At 3- and 6-month post-injury, 33.1% and 28.3% of limbs had very abnormal CMAP amplitudes, respectively, while in 54.1% and 51.7%, CMAPs were sub-normal. Median change in amplitude from 3 to 6 months was 0.0 mV for very abnormal and 1.0 mV for subnormal groups. A 3-month ulnar CMAP <1 mV had a positive predictive value of 0.73 (95% CI 0.69-0.76) and 0.78 (95% CI 0.75-0.80) for C8 and T1 muscle strength of 0 vs 1 or 2. CONCLUSION A high proportion of individuals have ulnar CMAPs below the lower limit of normal 3- and 6-month post cervical SCI and may also have intercurrent LMN injury. Failure to identify individuals with LMN denervation could result in a lost opportunity to improve hand function through timely nerve transfer surgeries.
Collapse
Affiliation(s)
- Michael J Berger
- International Collaboration on Repair Discoveries (ICORD), Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada; Division of Physical Medicine & Rehabilitation, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
| | - Jana Dengler
- Division of Plastic Surgery, Tory Trauma Program, Sunnybrook Health Sciences Centre, Toronto, Ontario; Division of Plastic, Reconstructive and Aesthetic Surgery, Department of Surgery, University of Toronto, Toronto, Ontario
| | - Amanda Westman
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, MO
| | - Armin Curt
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
| | - Martin Schubert
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
| | | | - Norbert Weidner
- Spinal Cord Injury Center, Heidelberg University Hospital, Heidelberg, Germany
| | - Frank Röhrich
- BG Klinikum Bergmannstrost, Zentrum für Rückenmarkverletzte und Klinik für Orthopädie, Halle, Germany
| | - Ida K Fox
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, MO
| |
Collapse
|
4
|
Awuah WA, Ahluwalia A, Ghosh S, Roy S, Tan JK, Adebusoye FT, Ferreira T, Bharadwaj HR, Shet V, Kundu M, Yee ALW, Abdul-Rahman T, Atallah O. The molecular landscape of neurological disorders: insights from single-cell RNA sequencing in neurology and neurosurgery. Eur J Med Res 2023; 28:529. [PMID: 37974227 PMCID: PMC10652629 DOI: 10.1186/s40001-023-01504-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 11/03/2023] [Indexed: 11/19/2023] Open
Abstract
Single-cell ribonucleic acid sequencing (scRNA-seq) has emerged as a transformative technology in neurological and neurosurgical research, revolutionising our comprehension of complex neurological disorders. In brain tumours, scRNA-seq has provided valuable insights into cancer heterogeneity, the tumour microenvironment, treatment resistance, and invasion patterns. It has also elucidated the brain tri-lineage cancer hierarchy and addressed limitations of current models. Neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis have been molecularly subtyped, dysregulated pathways have been identified, and potential therapeutic targets have been revealed using scRNA-seq. In epilepsy, scRNA-seq has explored the cellular and molecular heterogeneity underlying the condition, uncovering unique glial subpopulations and dysregulation of the immune system. ScRNA-seq has characterised distinct cellular constituents and responses to spinal cord injury in spinal cord diseases, as well as provided molecular signatures of various cell types and identified interactions involved in vascular remodelling. Furthermore, scRNA-seq has shed light on the molecular complexities of cerebrovascular diseases, such as stroke, providing insights into specific genes, cell-specific expression patterns, and potential therapeutic interventions. This review highlights the potential of scRNA-seq in guiding precision medicine approaches, identifying clinical biomarkers, and facilitating therapeutic discovery. However, challenges related to data analysis, standardisation, sample acquisition, scalability, and cost-effectiveness need to be addressed. Despite these challenges, scRNA-seq has the potential to transform clinical practice in neurological and neurosurgical research by providing personalised insights and improving patient outcomes.
Collapse
Affiliation(s)
- Wireko Andrew Awuah
- Faculty of Medicine, Sumy State University, Zamonstanksya 7, Sumy, 40007, Ukraine
| | | | - Shankaneel Ghosh
- Institute of Medical Sciences and SUM Hospital, Bhubaneswar, India
| | - Sakshi Roy
- School of Medicine, Queen's University Belfast, Belfast, UK
| | | | | | - Tomas Ferreira
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | | | - Vallabh Shet
- Faculty of Medicine, Bangalore Medical College and Research Institute, Bangalore, Karnataka, India
| | - Mrinmoy Kundu
- Institute of Medical Sciences and SUM Hospital, Bhubaneswar, India
| | | | - Toufik Abdul-Rahman
- Faculty of Medicine, Sumy State University, Zamonstanksya 7, Sumy, 40007, Ukraine
| | - Oday Atallah
- Department of Neurosurgery, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625, Hannover, Germany
| |
Collapse
|
5
|
Jack A, Rajshekar M, Witiw CD, Curran MWT, Olson JL, Morhart MJ, Jacques L, Chan KM. Characterization of Spinal Cord Injury Patients for Arm Functional Restoration through Nerve Transfer. Can J Neurol Sci 2023:1-5. [PMID: 37545347 DOI: 10.1017/cjn.2023.255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
INTRODUCTION Traumatic spinal cord injuries (tSCI) are common, often leaving patients irreparably debilitated. Therefore, novel strategies such as nerve transfers (NT) are needed for mitigating secondary SCI damage and improving function. Although different tSCI NT options exist, little is known about the epidemiological and injury-related aspects of this patient population. Here, we report such characteristics to better identify and understand the number and types of tSCI individuals who may benefit from NTs. MATERIALS AND METHODS Two peripheral nerve experts independently evaluated all adult tSCI individuals < 80 years old admitted with cervical tSCI (C1-T1) between 2005 and 2019 with documented tSCI severity using the ASIA Impairment Scale for suitability for NT (nerve donor with MRC strength ≥ 4/5 and recipient ≤ 2/5). Demographic, traumatic injury, and neurological injury variables were collected and analyzed. RESULTS A total of 709 tSCI individuals were identified with 224 (32%) who met the selection criteria for participation based on their tSCI level (C1-T1). Of these, 108 (15% of all tSCIs and 48% of all cervical tSCIs) were deemed to be appropriate NT candidates. Due to recovery, 6 NT candidates initially deem appropriate no longer qualified by their last follow-up. Conversely, 19 individuals not initially considered appropriate then become eligible by their last follow-up. CONCLUSION We found that a large proportion of individuals with cervical tSCI could potentially benefit from NTs. To our knowledge, this is the first study to detail the number of tSCI individuals that may qualify for NT from a large prospective database.
Collapse
Affiliation(s)
- Andrew Jack
- Division of Neurosurgery, Department of Surgery, University of Alberta, Edmonton, AB, Canada
| | - Mithun Rajshekar
- Division of Physical Medicine and Rehabilitation, Department of Medicine, University of Alberta, Edmonton, AB, Canada
| | - Christopher D Witiw
- Division of Neurosurgery, Department of SurgeryUniversity of Toronto, Toronto, ON, Canada
| | - Matthew W T Curran
- Division of Plastic and Reconstructive Surgery, Department of Surgery, University of Alberta, Edmonton, AB, Canada
| | - Jaret L Olson
- Division of Plastic and Reconstructive Surgery, Department of Surgery, University of Alberta, Edmonton, AB, Canada
| | - Michael J Morhart
- Division of Plastic and Reconstructive Surgery, Department of Surgery, University of Alberta, Edmonton, AB, Canada
| | - Line Jacques
- Division of Neurological Surgery, University of California San Francisco (UCSF), San Francisco, CA, USA
| | - K Ming Chan
- Division of Physical Medicine and Rehabilitation, Department of Medicine, University of Alberta, Edmonton, AB, Canada
| |
Collapse
|
6
|
Anterior interosseous nerve neuropathy in a patient with spinal cord injury: case report and literature review. Spinal Cord Ser Cases 2022; 8:61. [DOI: 10.1038/s41394-022-00527-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 06/08/2022] [Accepted: 06/09/2022] [Indexed: 11/09/2022] Open
|
7
|
Berger MJ, Adewuyi AA, Fox IK, Franz CK. Clinical electrodiagnostic evaluation for nerve transfer surgery in spinal cord injury: a new indication and clinical pearls. J Neurophysiol 2022; 128:847-853. [PMID: 36043801 PMCID: PMC10190829 DOI: 10.1152/jn.00289.2022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 08/23/2022] [Accepted: 08/26/2022] [Indexed: 11/22/2022] Open
Abstract
In this review, we highlight the important role of the clinical electrodiagnostic (EDX) evaluation after cervical spinal cord injury (SCI). Our discussion focuses on the need for timely, frequent, and accurate EDX evaluations in the context of nerve transfer surgery to restore critical upper limb functions, including elbow extension, hand opening, and hand closing. The EDX evaluation is crucial to define the extent of lower motor neuron lesions and determine candidacy for surgery. We also discuss the important role of the postoperative EDX evaluation in determining prognosis and supporting rehabilitation. We propose a practical framework for EDX evaluation in this clinical setting.
Collapse
Affiliation(s)
- Michael J Berger
- International Collaboration on Repair Discoveries (ICORD), Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- Division of Physical Medicine & Rehabilitation, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Adenike A Adewuyi
- Regenerative Neurorehabilitation Laboratory, Shirley Ryan AbilityLab, Chicago, Illinois
- Physical Medicine and Rehabilitation, Northwestern University Feinberg School of Medicine, Chicago, Illinois
- Ken & Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Ida K Fox
- Division of Plastic Surgery, Department of Surgery, Washington University School of Medicine, Saint Louis, Missouri
| | - Colin K Franz
- Regenerative Neurorehabilitation Laboratory, Shirley Ryan AbilityLab, Chicago, Illinois
- Physical Medicine and Rehabilitation, Northwestern University Feinberg School of Medicine, Chicago, Illinois
- Ken & Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| |
Collapse
|
8
|
Dengler J, Steeves JD, Curt A, Mehra M, Novak CB, Fox IK. Spontaneous Motor Recovery after Cervical Spinal Cord Injury: Issues for Nerve Transfer Surgery Decision Making. Spinal Cord 2022; 60:922-927. [PMID: 35896613 DOI: 10.1038/s41393-022-00834-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 06/28/2022] [Accepted: 06/30/2022] [Indexed: 11/09/2022]
Abstract
STUDY DESIGN Retrospective cohort study. OBJECTIVES To quantify spontaneous upper extremity motor recovery between 6 and 12 months after spinal cord injury (SCI) to help guide timing of nerve transfer surgery to improve upper limb function in cervical SCI. SETTING Nineteen European SCI rehabilitation centers. METHODS Data was extracted from the European Multicenter Study of SCI database for individuals with mid-level cervical SCI (N = 268). Muscle function grades at 6 and 12 months post-SCI were categorized for analysis. RESULTS From 6 to 12 months after SCI, spontaneous surgically-relevant recovery was limited. Of all limbs (N = 263) with grade 0-2 elbow extension at 6 months, 4% regained grade 4-5 and 11% regained grade 3 muscle function at 12 months. Of all limbs (N = 380) with grade 0-2 finger flexion at 6 months, 3% regained grade 4-5 and 5% regained grade 3 muscle function at 12 months. CONCLUSION This information supports early (6 month) post-injury surgical consultation and evaluation. With this information, individuals with SCI can more fully engage in preference-based decision-making about surgical intervention versus continued rehabilitation and spontaneous recovery to gain elbow extension and/or hand opening and closing.
Collapse
Affiliation(s)
- Jana Dengler
- Division of Plastic and Reconstructive Surgery, Tory Trauma Program, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.,University of Toronto, Division of Plastic & Reconstructive Surgery, Toronto, Ontario, Canada
| | - John D Steeves
- ICORD, University of British Columbia, Vancouver British Columbia, Vancouver, Canada
| | - Armin Curt
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
| | - Munish Mehra
- Tigermed-BDM Inc, Gaithersburg Maryland, Maryland, USA
| | - Christine B Novak
- University of Toronto, Division of Plastic & Reconstructive Surgery, Toronto, Ontario, Canada
| | | | | | - Ida K Fox
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Washington University School of Medicine, St Louis Missouri, USA. .,VA St. Louis Healthcare System, St Louis Missouri, USA.
| |
Collapse
|
9
|
Silverman J, Dengler J, Song C, Robinson LR. Pre-operative electrodiagnostic planning for upper limb peripheral nerve transfers in cervical spinal cord injury: A Narrative Review. PM R 2022. [PMID: 35726540 DOI: 10.1002/pmrj.12868] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 02/13/2022] [Accepted: 05/31/2022] [Indexed: 11/08/2022]
Abstract
Peripheral nerve transfer (PNT) to improve upper limb function following cervical spinal cord injury (SCI) involves the transfer of supralesional donor nerves under voluntary control to intralesional or sublesional lower motor neurons not under voluntary control. Appropriate selection of donor and recipient nerves and surgical timing impact functional outcomes. While the gold standard of nerve selection is intra-operative nerve stimulation, preoperative electrodiagnostic (EDX) evaluation may help guide surgical planning. Currently there is no standardized preoperative EDX protocol. This study reviews the EDX workup preceding peripheral nerve transfer surgery in cervical SCI, and proposes an informed EDX protocol to assist with surgical planning. The PICO (Population, Intervention, Comparison, Outcome) framework was used to formulate relevant MeSH terms and identify published cases of PNT in cervical SCI in Medline, Embase, CINAHL, and Emcare databases in the last 10 years. The electrodiagnostic techniques evaluating putative donor nerves, recipient nerve branches, time-sensitivity of nerve transfer and other electrophysiological parameters were summarized to guide creation of a preoperative EDX protocol. Needle electromyography (EMG) was the most commonly used EDX technique to identify healthy donor nerves. Although needle EMG has also been used on recipient nerves, compound muscle action potential (CMAP) amplitudes may provide a more accurate determination of recipient nerve health and time-sensitivity for nerve transfer. While there has been progress in pre-surgical EDX evaluation, EMG and NCS approaches are quite variable, and each has limitations in their utility for pre-operative planning. There is need for standardization in the EDX evaluation preceding peripheral nerve transfer surgery to assist with donor and recipient nerve selection, surgical timing and to optimize outcomes. Based on results of this review, herein we propose the PreSCIse (PRotocol for Electrodiagnosis in SCI Surgery of the upper Extremity) pre-operative EDX panel to achieve said goals through an interdisciplinary and patient-centered approach. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
- Jordan Silverman
- Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Jana Dengler
- Division of Plastic and Reconstructive Surgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - Cimon Song
- Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Lawrence R Robinson
- Sunnybrook Health Sciences Center, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
10
|
Manna M, Mortenson WB, Kardeh B, Douglas S, Marks C, Krauss EM, Berger MJ. Patient perspectives and self-rated knowledge of nerve transfer surgery for restoring upper limb function in spinal cord injury. PM R 2022; 15:579-586. [PMID: 35352495 DOI: 10.1002/pmrj.12811] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 02/06/2022] [Accepted: 03/16/2022] [Indexed: 11/11/2022]
Abstract
BACKGROUND Nerve transfer surgery has the potential to restore upper limb function in patients with spinal cord injury (SCI); however, there has been limited exploration of patient perception of nerve transfer. OBJECTIVE To explore the perspectives of patients with chronic SCI (>2 years from injury) on nerve transfer surgery, and to determine if an educational intervention improved participants' perceived knowledge levels about the procedure. DESIGN Mixed-methods study including qualitative semi-structured interviews and self-reported rating scales. Pre- and post-interviews were completed following an educational presentation. SETTING Two local SCI clinics. PARTICIPANTS Ten patients with chronic traumatic SCI and neurological level of injury C3-C7 (motor complete or incomplete), recruited via snowball sampling (six male, four female). INTERVENTION An educational slide presentation on nerve transfer concepts. MAIN OUTCOME MEASURES The primary study outcome measure is the participants' responses to interview questions. The secondary study outcome measure is their self-reported knowledge levels of nerve transfer before and after education. RESULTS Regaining upper limb function was a priority for all participants. Although most participants had heard of nerve transfer, none were offered it at the time of their SCI, and only two stated that they had any peers who had undergone the procedure. The educational module significantly increased self-rated scores on understanding of nerve transfer (p < .05). Although all participants were open to nerve transfer after the educational module, they described weighing different factors, including (1) potential for loss versus gain of function, (2) inadequate knowledge about nerve transfer, (3) recovery time, and (4) determining their eligibility for the surgery. CONCLUSIONS These findings suggest that people with SCI have limited understanding of nerve transfer as a potential option and would benefit from educational opportunities to help them make informed decisions. This study may inform the development of patient resources to improve pre-surgical consultation and informed decision-making.
Collapse
Affiliation(s)
- Mariam Manna
- Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - W Ben Mortenson
- Department of Occupational Science and Occupational Therapy, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada; International Collaboration on Repair Discoveries (ICORD),Vancouver, British Columbia, Canada; GF Strong Rehabilitation Research Program, Vancouver, British Columbia, Canada
| | - Bahareh Kardeh
- Graduate Program in Rehabilitation Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada; Rehabilitation Research Program, GF Strong Rehabilitation Research Program, Vancouver, British Columbia, Canada
| | - Sam Douglas
- University of Victoria, Victoria, British Columbia, Canada
| | - Chris Marks
- Praxis Spinal Cord Institute, Vancouver, British Columbia, Canada
| | - Emily M Krauss
- Division of Plastic Surgery, Department of Surgery, University of British Columbia, Victoria, British Columbia, Canada
| | - Michael J Berger
- International Collaboration on Repair Discoveries (ICORD), Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada; Division of Physical Medicine & Rehabilitation, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| |
Collapse
|
11
|
Plasticity of the Central Nervous System Involving Peripheral Nerve Transfer. Neural Plast 2022; 2022:5345269. [PMID: 35342394 PMCID: PMC8956439 DOI: 10.1155/2022/5345269] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 02/09/2022] [Accepted: 02/28/2022] [Indexed: 11/22/2022] Open
Abstract
Peripheral nerve injury can lead to partial or complete loss of limb function, and nerve transfer is an effective surgical salvage for patients with these injuries. The inability of deprived cortical regions representing damaged nerves to overcome corresponding maladaptive plasticity after the reinnervation of muscle fibers and sensory receptors is thought to be correlated with lasting and unfavorable functional recovery. However, the concept of central nervous system plasticity is rarely elucidated in classical textbooks involving peripheral nerve injury, let alone peripheral nerve transfer. This article is aimed at providing a comprehensive understanding of central nervous system plasticity involving peripheral nerve injury by reviewing studies mainly in human or nonhuman primate and by highlighting the functional and structural modifications in the central nervous system after peripheral nerve transfer. Hopefully, it will help surgeons perform successful nerve transfer under the guidance of modern concepts in neuroplasticity.
Collapse
|
12
|
Abstract
Nerve transfer surgery has expanded reconstructive options for restoring upper extremity function following spinal cord injury. By adding new motor donors to the pool already available through tendon transfers, the effectiveness of treatment should improve. Planning which procedures and in which order to perform, along with their details must be delineated. To meet these demands, refined diagnostics are needed, along with awareness of the remaining challenges to restore intrinsic muscle function and to address spasticity and its consequences. This article summaries recent advances in surgical reanimation of upper extremity motor control, together with an overview of the development of neuro-prosthetic and neuromodulation techniques to modify recovery or substitute for functional losses after spinal cord injuries.
Collapse
Affiliation(s)
- Jan Fridén
- Department of Tetrahand Surgery, Swiss Paraplegic Centre, Nottwil, Switzerland
| | - James House
- Department of Orthopaedic Surgery, University of Minnesota, Minneapolis, MN, USA
| | - Michael Keith
- Departments of Orthopaedic Surgery, BioMedical Engineering, Physical Medicine and Rehabilitation, Case Western Reserve University, Cleveland, OH, USA
| | - Silvia Schibli
- Department of Tetrahand Surgery, Swiss Paraplegic Centre, Nottwil, Switzerland
| | - Natasha van Zyl
- Department of Plastic and Reconstructive Surgery, Austin Health, Melbourne, VIC, Australia
| |
Collapse
|
13
|
Mauti E, Robinson LR. Radial motor nerve conduction studies recorded from triceps brachii and extensor carpi radialis longus: Techniques and reference values. Muscle Nerve 2021; 65:337-340. [PMID: 34862799 DOI: 10.1002/mus.27470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 11/27/2021] [Accepted: 11/30/2021] [Indexed: 11/10/2022]
Abstract
INTRODUCTION/AIMS Optimal timing of nerve transfer surgery in cervical spinal cord injury (SCI) depends upon the integrity of lower motor neurons (LMNs) in recipient nerves, which is best predicted by compound muscle action potential (CMAP) amplitude. There are no established techniques for obtaining the CMAP in two recipient muscles: triceps brachii and extensor carpi radialis longus (ECRL). This study aimed to develop recording techniques for radial motor studies to triceps and ECRL, and to determine reference values for CMAP amplitudes in healthy volunteers. METHODS This was a prospective observational study of healthy adults aged 18 years and older. Motor nerve conduction studies were performed, stimulating the radial nerve in the axilla, over the axillary pulse at the pectoralis major insertion. Recording was from triceps (long head) and ECRL. CMAP amplitude, area, latency, and stimulus intensity were recorded. Reference values (RV) were calculated for CMAP amplitudes using a value 2 standard deviations below the mean. Cube root or logarithmic transformations were used to correct for non-normal distributions. RESULTS Twenty-five healthy subjects participated. Triceps mean CMAP amplitude was 15.5 mV (SD 4.19), with an RV of 8.1 mV. ECRL mean CMAP amplitude was 11.5 mV (SD 3.54), with an RV of 6.2 mV. CMAP amplitude at ECRL was 75% (95% confidence interval 50%-100%) of that at triceps. DISCUSSION We describe a technique for recording radial motor NCS from triceps and ECRL. Knowledge of normal CMAP amplitudes will help identify LMN injury in patients with cervical SCI being considered for nerve transfers.
Collapse
Affiliation(s)
- Emma Mauti
- Division of Physical Medicine & Rehabilitation, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Lawrence R Robinson
- Division of Physical Medicine & Rehabilitation, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|