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Frey VN, Langthaler PB, Renz N, Zimmermann G, Höhn C, Schwenker K, Thomschewski A, Kunz AB, Höller Y, Nardone R, Trinka E. Influence of sports on cortical excitability in patients with spinal cord injury: a TMS study. FRONTIERS IN MEDICAL TECHNOLOGY 2024; 6:1297552. [PMID: 38812566 PMCID: PMC11133579 DOI: 10.3389/fmedt.2024.1297552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 04/19/2024] [Indexed: 05/31/2024] Open
Abstract
Background Patients with spinal cord injury (SCI) show abnormal cortical excitability that might be caused by deafferentation. We hypothesize a reduced short-interval intracortical inhibition preceding movement in patients with SCI compared with healthy participants. In addition, we expect that neuroplasticity induced by different types of sports can modulate intracortical inhibition during movement preparation in patients with SCI. Methods We used a reaction test and paired-pulse transcranial magnetic stimulation to record cortical excitability, assessed by measuring amplitudes of motor-evoked potentials in preparation of movement. The participants were grouped as patients with SCI practicing wheelchair dancing (n = 7), other sports (n = 6), no sports (n = 9), and healthy controls (n = 24). Results There were neither significant differences between healthy participants and the patients nor between the different patient groups. A non-significant trend (p = .238), showed that patients engaged in sports have a stronger increase in cortical excitability compared with patients of the non-sportive group, while the patients in the other sports group expressed the highest increase in cortical excitability. Conclusion The small sample sizes limit the statistical power of the study, but the trending effect warrants further investigation of different sports on the neuroplasticity in patients with SCI. It is not clear how neuroplastic changes impact the sensorimotor output of the affected extremities in a patient. This needs to be followed up in further studies with a greater sample size.
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Affiliation(s)
- Vanessa N. Frey
- Department of Neurology, Neurointensive Care and Neurorehabilitation, Member of the European Reference Network EpiCARE, Christian Doppler University Hospital, Centre for Cognitive Neuroscience, Paracelsus Medical University Salzburg, Salzburg, Austria
- Spinal Cord Injury and Tissue Regeneration Center, Paracelsus Medical University, Salzburg, Austria
| | - Patrick B. Langthaler
- Department of Neurology, Neurointensive Care and Neurorehabilitation, Member of the European Reference Network EpiCARE, Christian Doppler University Hospital, Centre for Cognitive Neuroscience, Paracelsus Medical University Salzburg, Salzburg, Austria
- Spinal Cord Injury and Tissue Regeneration Center, Paracelsus Medical University, Salzburg, Austria
- Department of Mathematics, Paris Lodron University, Salzburg, Austria
| | - Nora Renz
- Department of Neurology, Neurointensive Care and Neurorehabilitation, Member of the European Reference Network EpiCARE, Christian Doppler University Hospital, Centre for Cognitive Neuroscience, Paracelsus Medical University Salzburg, Salzburg, Austria
- Spinal Cord Injury and Tissue Regeneration Center, Paracelsus Medical University, Salzburg, Austria
| | - Georg Zimmermann
- Department of Neurology, Neurointensive Care and Neurorehabilitation, Member of the European Reference Network EpiCARE, Christian Doppler University Hospital, Centre for Cognitive Neuroscience, Paracelsus Medical University Salzburg, Salzburg, Austria
- IDA Lab Salzburg, Team Biostatistics and Big Medical Data, Paracelsus Medical University Salzburg, Salzburg, Austria
| | - Christopher Höhn
- Laboratory for Sleep, Cognition and Consciousness Research, Department of Psychology, Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria
| | - Kerstin Schwenker
- Department of Neurology, Neurointensive Care and Neurorehabilitation, Member of the European Reference Network EpiCARE, Christian Doppler University Hospital, Centre for Cognitive Neuroscience, Paracelsus Medical University Salzburg, Salzburg, Austria
- Spinal Cord Injury and Tissue Regeneration Center, Paracelsus Medical University, Salzburg, Austria
- Karl Landsteiner Institute for Neurorehabilitation and Space Neurology Salzburg, Salzburg, Austria
| | - Aljoscha Thomschewski
- Department of Neurology, Neurointensive Care and Neurorehabilitation, Member of the European Reference Network EpiCARE, Christian Doppler University Hospital, Centre for Cognitive Neuroscience, Paracelsus Medical University Salzburg, Salzburg, Austria
- Spinal Cord Injury and Tissue Regeneration Center, Paracelsus Medical University, Salzburg, Austria
| | - Alexander B. Kunz
- Department of Neurology, Neurointensive Care and Neurorehabilitation, Member of the European Reference Network EpiCARE, Christian Doppler University Hospital, Centre for Cognitive Neuroscience, Paracelsus Medical University Salzburg, Salzburg, Austria
- Karl Landsteiner Institute for Neurorehabilitation and Space Neurology Salzburg, Salzburg, Austria
| | - Yvonne Höller
- Department of Neurology, Neurointensive Care and Neurorehabilitation, Member of the European Reference Network EpiCARE, Christian Doppler University Hospital, Centre for Cognitive Neuroscience, Paracelsus Medical University Salzburg, Salzburg, Austria
- Faculty of Psychology, University of Akureyri, Akureyri, Iceland
| | - Raffaele Nardone
- Department of Neurology, Neurointensive Care and Neurorehabilitation, Member of the European Reference Network EpiCARE, Christian Doppler University Hospital, Centre for Cognitive Neuroscience, Paracelsus Medical University Salzburg, Salzburg, Austria
- Spinal Cord Injury and Tissue Regeneration Center, Paracelsus Medical University, Salzburg, Austria
- Karl Landsteiner Institute for Neurorehabilitation and Space Neurology Salzburg, Salzburg, Austria
- Department of Neurology, Tappeiner Hospital, Meran, Italy
| | - Eugen Trinka
- Department of Neurology, Neurointensive Care and Neurorehabilitation, Member of the European Reference Network EpiCARE, Christian Doppler University Hospital, Centre for Cognitive Neuroscience, Paracelsus Medical University Salzburg, Salzburg, Austria
- Spinal Cord Injury and Tissue Regeneration Center, Paracelsus Medical University, Salzburg, Austria
- Karl Landsteiner Institute for Neurorehabilitation and Space Neurology Salzburg, Salzburg, Austria
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Arora T, Desai N, Kirshblum S, Chen R. Utility of transcranial magnetic stimulation in the assessment of spinal cord injury: Current status and future directions. FRONTIERS IN REHABILITATION SCIENCES 2022; 3:1005111. [PMID: 36275924 PMCID: PMC9581184 DOI: 10.3389/fresc.2022.1005111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 09/16/2022] [Indexed: 11/06/2022]
Abstract
Comprehensive assessment following traumatic spinal cord injury (SCI) is needed to improve prognostication, advance the understanding of the neurophysiology and better targeting of clinical interventions. The International Standards for Neurological Classification of Spinal Cord Injury is the most common clinical examination recommended for use after a SCI. In addition, there are over 30 clinical assessment tools spanning across different domains of the International Classification of Functioning, Disability, and Health that have been validated and recommended for use in SCI. Most of these tools are subjective in nature, have limited value in predicting neurologic recovery, and do not provide insights into neurophysiological mechanisms. Transcranial magnetic stimulation (TMS) is a non-invasive neurophysiology technique that can supplement the clinical assessment in the domain of body structure and function during acute and chronic stages of SCI. TMS offers a better insight into neurophysiology and help in better detection of residual corticomotor connectivity following SCI compared to clinical assessment alone. TMS-based motor evoked potential and silent period duration allow study of excitatory and inhibitory mechanisms following SCI. Changes in muscle representations in form of displacement of TMS-based motor map center of gravity or changes in the map area can capture neuroplastic changes resulting from SCI or following rehabilitation. Paired-pulse TMS measures help understand the compensatory reorganization of the cortical circuits following SCI. In combination with peripheral stimulation, TMS can be used to study central motor conduction time and modulation of spinal reflexes, which can be used for advanced diagnostic and treatment purposes. To strengthen the utility of TMS in SCI assessment, future studies will need to standardize the assessment protocols, address population-specific concerns, and establish the psychometric properties of TMS-based measurements in the SCI population.
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Affiliation(s)
- Tarun Arora
- Krembil Research Institute, University Health Network, Toronto, ON, Canada,Correspondence: Tarun Arora Robert Chen
| | - Naaz Desai
- Krembil Research Institute, University Health Network, Toronto, ON, Canada
| | - Steven Kirshblum
- Department of Physical Medicine and Rehabilitation, Rutgers New Jersey Medical School, Newark, NJ, United States,Kessler Institute for Rehabilitation, West Orange, NJ, United States,Kessler Foundation, West Orange, NJ, United States,Rutgers New Jersey Medical School, Newark, NJ, United States
| | - Robert Chen
- Krembil Research Institute, University Health Network, Toronto, ON, Canada,Edmond J. Safra Program in Parkinson’s Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Toronto, ON, Canada,Division of Neurology, University of Toronto, Toronto, ON, Canada,Correspondence: Tarun Arora Robert Chen
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Benedetti B, Weidenhammer A, Reisinger M, Couillard-Despres S. Spinal Cord Injury and Loss of Cortical Inhibition. Int J Mol Sci 2022; 23:5622. [PMID: 35628434 PMCID: PMC9144195 DOI: 10.3390/ijms23105622] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 05/09/2022] [Accepted: 05/13/2022] [Indexed: 02/04/2023] Open
Abstract
After spinal cord injury (SCI), the destruction of spinal parenchyma causes permanent deficits in motor functions, which correlates with the severity and location of the lesion. Despite being disconnected from their targets, most cortical motor neurons survive the acute phase of SCI, and these neurons can therefore be a resource for functional recovery, provided that they are properly reconnected and retuned to a physiological state. However, inappropriate re-integration of cortical neurons or aberrant activity of corticospinal networks may worsen the long-term outcomes of SCI. In this review, we revisit recent studies addressing the relation between cortical disinhibition and functional recovery after SCI. Evidence suggests that cortical disinhibition can be either beneficial or detrimental in a context-dependent manner. A careful examination of clinical data helps to resolve apparent paradoxes and explain the heterogeneity of treatment outcomes. Additionally, evidence gained from SCI animal models indicates probable mechanisms mediating cortical disinhibition. Understanding the mechanisms and dynamics of cortical disinhibition is a prerequisite to improve current interventions through targeted pharmacological and/or rehabilitative interventions following SCI.
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Affiliation(s)
- Bruno Benedetti
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020 Salzburg, Austria; (B.B.); (A.W.); (M.R.)
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), 5020 Salzburg, Austria
- Austrian Cluster for Tissue Regeneration, 1200 Vienna, Austria
| | - Annika Weidenhammer
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020 Salzburg, Austria; (B.B.); (A.W.); (M.R.)
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), 5020 Salzburg, Austria
| | - Maximilian Reisinger
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020 Salzburg, Austria; (B.B.); (A.W.); (M.R.)
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), 5020 Salzburg, Austria
| | - Sebastien Couillard-Despres
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020 Salzburg, Austria; (B.B.); (A.W.); (M.R.)
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), 5020 Salzburg, Austria
- Austrian Cluster for Tissue Regeneration, 1200 Vienna, Austria
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Liu X, Li C, Li J, Xie L, Hong Z, Zheng K, Zhao X, Yang A, Xu X, Tao H, Qiu M, Yang J. EGF signaling promotes the lineage conversion of astrocytes into oligodendrocytes. Mol Med 2022; 28:50. [PMID: 35508991 PMCID: PMC9066914 DOI: 10.1186/s10020-022-00478-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Accepted: 04/18/2022] [Indexed: 12/15/2022] Open
Abstract
Background The conversion of astrocytes activated by nerve injuries to oligodendrocytes is not only beneficial to axonal remyelination, but also helpful for reversal of glial scar. Recent studies have shown that pathological niche promoted the Sox10-mediated astrocytic transdifferentiation to oligodendrocytes. The extracellular factors underlying the cell fate switching are not known. Methods Astrocytes were obtained from mouse spinal cord dissociation culture and purified by differential adherent properties. The lineage conversion of astrocytes into oligodendrocyte lineage cells was carried out by Sox10-expressing virus infection both in vitro and in vivo, meanwhile, epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) inhibitor Gefitinib were adopted to investigate the function of EGF signaling in this fate transition process. Pharmacological inhibition analyses were performed to examine the pathway connecting the EGF with the expression of oligodendrogenic genes and cell fate transdifferentiation. Results EGF treatment facilitated the Sox10-induced transformation of astrocytes to O4+ induced oligodendrocyte precursor cells (iOPCs) in vitro. The transdifferentiation of astrocytes to iOPCs went through two distinct but interconnected processes: (1) dedifferentiation of astrocytes to astrocyte precursor cells (APCs); (2) transformation of APCs to iOPCs, EGF signaling was involved in both processes. And EGF triggered astrocytes to express oligodendrogenic genes Olig1 and Olig2 by activating extracellular signal-regulated kinase 1 and 2 (Erk1/2) pathway. In addition, we discovered that EGF can enhance astrocyte transdifferentiation in injured spinal cord tissues. Conclusions These findings provide strong evidence that EGF facilitates the transdifferentiation of astrocytes to oligodendrocytes, and suggest that targeting the EGF-EGFR-Erk1/2 signaling axis may represent a novel therapeutic strategy for myelin repair in injured central nervous system (CNS) tissues. Supplementary Information The online version contains supplementary material available at 10.1186/s10020-022-00478-5.
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Affiliation(s)
- Xinyu Liu
- College of Life Sciences, Zhejiang University, Hangzhou, 310058, China.,College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 311121, China.,Key Laboratory of Organ Development and Regeneration of Zhejiang Province, Hangzhou, 311121, China
| | - Conghui Li
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 311121, China.,Key Laboratory of Organ Development and Regeneration of Zhejiang Province, Hangzhou, 311121, China
| | - Jiao Li
- Department of Eugenics and Genetics, Maternal and Child Health Care Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530003, China
| | - Lesi Xie
- Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, China
| | - Zeng Hong
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 311121, China.,Key Laboratory of Organ Development and Regeneration of Zhejiang Province, Hangzhou, 311121, China
| | - Kang Zheng
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 311121, China.,Key Laboratory of Organ Development and Regeneration of Zhejiang Province, Hangzhou, 311121, China
| | - Xiaofeng Zhao
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 311121, China.,Key Laboratory of Organ Development and Regeneration of Zhejiang Province, Hangzhou, 311121, China
| | - Aifen Yang
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 311121, China.,Key Laboratory of Organ Development and Regeneration of Zhejiang Province, Hangzhou, 311121, China
| | - Xiaofeng Xu
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 311121, China.,Key Laboratory of Organ Development and Regeneration of Zhejiang Province, Hangzhou, 311121, China
| | - Huaping Tao
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 311121, China.,Key Laboratory of Organ Development and Regeneration of Zhejiang Province, Hangzhou, 311121, China
| | - Mengsheng Qiu
- College of Life Sciences, Zhejiang University, Hangzhou, 310058, China. .,College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 311121, China. .,Key Laboratory of Organ Development and Regeneration of Zhejiang Province, Hangzhou, 311121, China.
| | - Junlin Yang
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 311121, China. .,Key Laboratory of Organ Development and Regeneration of Zhejiang Province, Hangzhou, 311121, China.
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5
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Quantitative electrophysiological assessments as predictive markers of lower limb motor recovery after spinal cord injury: a pilot study with an adaptive trial design. Spinal Cord Ser Cases 2022; 8:26. [PMID: 35210402 PMCID: PMC8873458 DOI: 10.1038/s41394-022-00491-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 01/27/2022] [Accepted: 02/01/2022] [Indexed: 11/13/2022] Open
Abstract
Study design Observational, cohort study. Objectives (1) Determine the feasibility and relevance of assessing corticospinal, sensory, and spinal pathways early after traumatic spinal cord injury (SCI) in a rehabilitation setting. (2) Validate whether electrophysiological and magnetic resonance imaging (MRI) measures taken early after SCI could identify preserved neural pathways, which could then guide therapy. Setting Intensive functional rehabilitation hospital (IFR). Methods Five individuals with traumatic SCI and eight controls were recruited. The lower extremity motor score (LEMS), electrical perceptual threshold (EPT) at the S2 dermatome, soleus (SOL) H-reflex, and motor evoked potentials (MEPs) in the tibialis anterior (TA) muscle were assessed during the stay in IFR and in the chronic stage (>6 months post-SCI). Control participants were only assessed once. Feasibility criteria included the absence of adverse events, adequate experimental session duration, and complete dataset gathering. The relationship between electrophysiological data collected in IFR and LEMS in the chronic phase was studied. The admission MRI was used to calculate the maximal spinal cord compression (MSCC). Results No adverse events occurred, but a complete dataset could not be collected for all subjects due to set-up configuration limitations and time constraints. EPT measured at IFR correlated with LEMS in the chronic phases (r = −0.67), whereas SOL H/M ratio, H latency, MEPs and MSCC did not. Conclusions Adjustments are necessary to implement electrophysiological assessments in an IFR setting. Combining MRI and electrophysiological measures may lead to better assessment of neuronal deficits early after SCI.
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Mao YR, Jin ZX, Zheng Y, Fan J, Zhao LJ, Xu W, Hu X, Gu CY, Lu WW, Zhu GY, Chen YH, Cheng LM, Xu DS. Effects of cortical intermittent theta burst stimulation combined with precise root stimulation on motor function after spinal cord injury: a case series study. Neural Regen Res 2022; 17:1821-1826. [PMID: 35017444 PMCID: PMC8820710 DOI: 10.4103/1673-5374.332158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Activation and reconstruction of the spinal cord circuitry is important for improving motor function following spinal cord injury. We conducted a case series study to investigate motor function improvement in 14 patients with chronic spinal cord injury treated with 4 weeks of unilateral (right only) cortical intermittent theta burst stimulation combined with bilateral magnetic stimulation of L3-L4 nerve roots, five times a week. Bilateral resting motor evoked potential amplitude was increased, central motor conduction time on the side receiving cortical stimulation was significantly decreased, and lower extremity motor score, Berg balance score, spinal cord independence measure-III score, and 10 m-walking speed were all increased after treatment. Right resting motor evoked potential amplitude was positively correlated with lower extremity motor score after 4 weeks of treatment. These findings suggest that cortical intermittent theta burst stimulation combined with precise root stimulation can improve nerve conduction of the corticospinal tract and lower limb motor function recovery in patients with chronic spinal cord injury.
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Affiliation(s)
- Ye-Ran Mao
- Department of Rehabilitation, Baoshan Branch, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine; Institute of Rehabilitation Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Zhong-Xia Jin
- Department of Spinal Cord Injury Rehabilitation, Shanghai Yangzhi Rehabilitation Hospital, Shanghai Sunshine Rehabilitation Center, Tongji University School of Medicine, Shanghai, China
| | - Ya Zheng
- Spine Surgery Division of Department of Orthopedics, Tongji Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
| | - Jian Fan
- Surgery Division of Department of Orthopedics, Tongji Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
| | - Li-Juan Zhao
- Spine Surgery Division of Department of Orthopedics, Tongji Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
| | - Wei Xu
- Spine Surgery Division of Department of Orthopedics, Tongji Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
| | - Xiao Hu
- Spine Surgery Division of Department of Orthopedics, Tongji Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
| | - Chun-Ya Gu
- Spine Surgery Division of Department of Orthopedics, Tongji Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
| | - Wei-Wei Lu
- Spine Surgery Division of Department of Orthopedics, Tongji Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
| | - Guang-Yue Zhu
- Spine Surgery Division of Department of Orthopedics, Tongji Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
| | - Yu-Hui Chen
- Spine Surgery Division of Department of Orthopedics, Tongji Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
| | - Li-Ming Cheng
- Spine Surgery Division of Department of Orthopedics, Tongji Hospital Affiliated to Tongji University School of Medicine; Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration, Ministry of Education, Shanghai, China
| | - Dong-Sheng Xu
- Institute of Rehabilitation Medicine, Shanghai University of Traditional Chinese Medicine; Engineering Research Center of Traditional Chinese Medicine Intelligent Rehabilitation, Ministry of Education, Shanghai, China
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7
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Santamaria AJ, Benavides FD, Saraiva PM, Anderson KD, Khan A, Levi AD, Dietrich WD, Guest JD. Neurophysiological Changes in the First Year After Cell Transplantation in Sub-acute Complete Paraplegia. Front Neurol 2021; 11:514181. [PMID: 33536992 PMCID: PMC7848788 DOI: 10.3389/fneur.2020.514181] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 11/05/2020] [Indexed: 12/15/2022] Open
Abstract
Neurophysiological testing can provide quantitative information about motor, sensory, and autonomic system connectivity following spinal cord injury (SCI). The clinical examination may be insufficiently sensitive and specific to reveal evolving changes in neural circuits after severe injury. Neurophysiologic data may provide otherwise imperceptible circuit information that has rarely been acquired in biologics clinical trials in SCI. We reported a Phase 1 study of autologous purified Schwann cell suspension transplantation into the injury epicenter of participants with complete subacute thoracic SCI, observing no clinical improvements. Here, we report longitudinal electrophysiological assessments conducted during the trial. Six participants underwent neurophysiology screening pre-transplantation with three post-transplantation neurophysiological assessments, focused on the thoracoabdominal region and lower limbs, including MEPs, SSEPs, voluntarily triggered EMG, and changes in GSR. We found several notable signals not detectable by clinical exam. In all six participants, thoracoabdominal motor connectivity was detected below the clinically assigned neurological level defined by sensory preservation. Additionally, small voluntary activations of leg and foot muscles or positive lower extremity MEPs were detected in all participants. Voluntary EMG was most sensitive to detect leg motor function. The recorded MEP amplitudes and latencies indicated a more caudal thoracic level above which amplitude recovery over time was observed. In contrast, further below, amplitudes showed less improvement, and latencies were increased. Intercostal spasms observed with EMG may also indicate this thoracic “motor level.” Galvanic skin testing revealed autonomic dysfunction in the hands above the injury levels. As an open-label study, we can establish no clear link between these observations and cell transplantation. This neurophysiological characterization may be of value to detect therapeutic effects in future controlled studies.
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Affiliation(s)
- Andrea J Santamaria
- The Miami Project to Cure Paralysis, Miller School of Medicine, The University of Miami, Miami, FL, United States
| | - Francisco D Benavides
- The Miami Project to Cure Paralysis, Miller School of Medicine, The University of Miami, Miami, FL, United States
| | - Pedro M Saraiva
- The Miami Project to Cure Paralysis, Miller School of Medicine, The University of Miami, Miami, FL, United States
| | - Kimberly D Anderson
- The Miami Project to Cure Paralysis, Miller School of Medicine, The University of Miami, Miami, FL, United States.,The Department of Neurological Surgery, Miller School of Medicine, The University of Miami, Miami, FL, United States
| | - Aisha Khan
- The Miami Project to Cure Paralysis, Miller School of Medicine, The University of Miami, Miami, FL, United States.,Miller School of Medicine, The Interdisciplinary Stem Cell Institute, The University of Miami, Miami, FL, United States
| | - Allan D Levi
- The Miami Project to Cure Paralysis, Miller School of Medicine, The University of Miami, Miami, FL, United States.,The Department of Neurological Surgery, Miller School of Medicine, The University of Miami, Miami, FL, United States
| | - W Dalton Dietrich
- The Miami Project to Cure Paralysis, Miller School of Medicine, The University of Miami, Miami, FL, United States.,The Department of Neurological Surgery, Miller School of Medicine, The University of Miami, Miami, FL, United States
| | - James D Guest
- The Miami Project to Cure Paralysis, Miller School of Medicine, The University of Miami, Miami, FL, United States.,The Department of Neurological Surgery, Miller School of Medicine, The University of Miami, Miami, FL, United States
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8
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Williams AM, Eginyan G, Deegan E, Chow M, Carpenter MG, Lam T. Residual Innervation of the Pelvic Floor Muscles in People with Motor-Complete Spinal Cord Injury. J Neurotrauma 2020; 37:2320-2331. [DOI: 10.1089/neu.2019.6908] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Alison M.M. Williams
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada
- International Collaboration On Repair Discoveries (ICORD), Vancouver Costal Health Research Institute, Vancouver, British Columbia, Canada
| | - Gevorg Eginyan
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada
- International Collaboration On Repair Discoveries (ICORD), Vancouver Costal Health Research Institute, Vancouver, British Columbia, Canada
| | - Emily Deegan
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada
- International Collaboration On Repair Discoveries (ICORD), Vancouver Costal Health Research Institute, Vancouver, British Columbia, Canada
| | - Mason Chow
- International Collaboration On Repair Discoveries (ICORD), Vancouver Costal Health Research Institute, Vancouver, British Columbia, Canada
| | - Mark G. Carpenter
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada
- International Collaboration On Repair Discoveries (ICORD), Vancouver Costal Health Research Institute, Vancouver, British Columbia, Canada
| | - Tania Lam
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada
- International Collaboration On Repair Discoveries (ICORD), Vancouver Costal Health Research Institute, Vancouver, British Columbia, Canada
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9
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TMS Correlates of Pyramidal Tract Signs and Clinical Motor Status in Patients with Cervical Spondylotic Myelopathy. Brain Sci 2020. [PMID: 33142762 DOI: 10.3390/brainsci10110806.] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND While the association between motor-evoked potential (MEP) abnormalities and motor deficit is well established, few studies have reported the correlation between MEPs and signs of pyramidal tract dysfunction without motor weakness. We assessed MEPs in patients with pyramidal signs, including motor deficits, compared to patients with pyramidal signs but without weakness. METHODS Forty-three patients with cervical spondylotic myelopathy (CSM) were dichotomized into 21 with pyramidal signs including motor deficit (Group 1) and 22 with pyramidal signs and normal strength (Group 2), and both groups were compared to 33 healthy controls (Group 0). MEPs were bilaterally recorded from the first dorsal interosseous and tibialis anterior muscle. The central motor conduction time (CMCT) was estimated as the difference between MEP latency and peripheral latency by magnetic stimulation. Peak-to-peak MEP amplitude and right-to-left differences were also measured. RESULTS Participants were age-, sex-, and height-matched. MEP latency in four limbs and CMCT in the lower limbs were prolonged, and MEP amplitude in the lower limbs decreased in Group 1 compared to the others. Unlike motor deficit, pyramidal signs were not associated with MEP measures, even when considering age, sex, and height as confounding factors. CONCLUSIONS In CSM, isolated pyramidal signs may not be associated, at this stage, with MEP changes.
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10
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Lanza G, Puglisi V, Vinciguerra L, Fisicaro F, Vagli C, Cantone M, Pennisi G, Pennisi M, Bella R. TMS Correlates of Pyramidal Tract Signs and Clinical Motor Status in Patients with Cervical Spondylotic Myelopathy. Brain Sci 2020; 10:brainsci10110806. [PMID: 33142762 PMCID: PMC7692772 DOI: 10.3390/brainsci10110806] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 10/23/2020] [Accepted: 10/26/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND While the association between motor-evoked potential (MEP) abnormalities and motor deficit is well established, few studies have reported the correlation between MEPs and signs of pyramidal tract dysfunction without motor weakness. We assessed MEPs in patients with pyramidal signs, including motor deficits, compared to patients with pyramidal signs but without weakness. METHODS Forty-three patients with cervical spondylotic myelopathy (CSM) were dichotomized into 21 with pyramidal signs including motor deficit (Group 1) and 22 with pyramidal signs and normal strength (Group 2), and both groups were compared to 33 healthy controls (Group 0). MEPs were bilaterally recorded from the first dorsal interosseous and tibialis anterior muscle. The central motor conduction time (CMCT) was estimated as the difference between MEP latency and peripheral latency by magnetic stimulation. Peak-to-peak MEP amplitude and right-to-left differences were also measured. RESULTS Participants were age-, sex-, and height-matched. MEP latency in four limbs and CMCT in the lower limbs were prolonged, and MEP amplitude in the lower limbs decreased in Group 1 compared to the others. Unlike motor deficit, pyramidal signs were not associated with MEP measures, even when considering age, sex, and height as confounding factors. CONCLUSIONS In CSM, isolated pyramidal signs may not be associated, at this stage, with MEP changes.
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Affiliation(s)
- Giuseppe Lanza
- Department of Surgery and Medical-Surgical Specialties, University of Catania, Via Santa Sofia, 78-95123 Catania, Italy;
- Department of Neurology IC, Oasi Research Institute–IRCCS, Via Conte Ruggero, 73-94018 Troina, Italy
- Correspondence: ; Tel.: +39-095-3782448
| | - Valentina Puglisi
- Department of Neurology and Stroke Unit, ASST Cremona, Viale Concordia, 1-26100 Cremona, Italy; (V.P.); (L.V.)
| | - Luisa Vinciguerra
- Department of Neurology and Stroke Unit, ASST Cremona, Viale Concordia, 1-26100 Cremona, Italy; (V.P.); (L.V.)
| | - Francesco Fisicaro
- Department of Biomedical and Biotechnological Sciences, University of Catania, Via Santa Sofia, 89-95123 Catania, Italy; (F.F.); (M.P.)
| | - Carla Vagli
- Department of Neurology, San Giovanni di Dio Hospital, ASP Agrigento, Contrada Consolida, 92100 Agrigento, Italy;
| | - Mariagiovanna Cantone
- Department of Neurology, Sant’Elia Hospital, ASP Caltanissetta, Via Luigi Russo, 6-93100 Caltanissetta, Italy;
| | - Giovanni Pennisi
- Department of Surgery and Medical-Surgical Specialties, University of Catania, Via Santa Sofia, 78-95123 Catania, Italy;
| | - Manuela Pennisi
- Department of Biomedical and Biotechnological Sciences, University of Catania, Via Santa Sofia, 89-95123 Catania, Italy; (F.F.); (M.P.)
| | - Rita Bella
- Department of Medical and Surgical Sciences and Advanced Technologies, University of Catania, Via Santa Sofia, 78-95123 Catania, Italy;
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Interlimb conditioning of lumbosacral spinally evoked motor responses after spinal cord injury. Clin Neurophysiol 2020; 131:1519-1532. [PMID: 32403065 DOI: 10.1016/j.clinph.2020.03.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 02/11/2020] [Accepted: 03/06/2020] [Indexed: 11/24/2022]
Abstract
OBJECTIVE The importance of subcortical pathways to functional motor recovery after spinal cord injury (SCI) has been demonstrated in multiple animal models. The current study evaluated descending interlimb influence on lumbosacral motor excitability after chronic SCI in humans. METHODS Ulnar nerve stimulation and transcutaneous electrical spinal stimulation were used in a condition-test paradigm to evaluate the presence of interlimb connections linking the cervical and lumbosacral spinal segments in non-injured (n=15) and spinal cord injured (SCI) (n=18) participants. RESULTS Potentiation of spinally evoked motor responses (sEMRs) by ulnar nerve conditioning was observed in 7/7 SCI participants with volitional leg muscle activation, and in 6/11 SCI participants with no volitional activation. Of these six, conditioning of sEMRs was present only when the neurological level of injury was rostral to the ulnar innervation entry zones. CONCLUSIONS Descending modulation of lumbosacral motor pools via interlimb projections may exist in SCI participants despite the absence of volitional leg muscle activation. SIGNIFICANCE Evaluation of sub-clinical, spared pathways within the spinal cord after SCI may provide an improved understanding of both the contributions of different pathways to residual function, and the mechanisms of plasticity and functional motor recovery following rehabilitation..
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Lanza G, Cantone M, Puglisi V, Vinciguerra L, Fisicaro F, Vagli C, Bella R, Pennisi G, Di Lazzaro V, Pennisi M. "Mute" plantar response: does the cortico-spinal tract "speak"? Brain Stimul 2019; 12:1579-1580. [PMID: 31362869 DOI: 10.1016/j.brs.2019.07.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 07/10/2019] [Indexed: 02/07/2023] Open
Affiliation(s)
- Giuseppe Lanza
- Department of Surgery and Medical-Surgical Specialties, University of Catania, Italy; Department of Neurology IC, Oasi Research Institute - IRCCS, Troina, Italy
| | - Mariagiovanna Cantone
- Department of Neurology, Sant'Elia Hospital, ASP Caltanissetta, Caltanissetta, Italy.
| | - Valentina Puglisi
- Department of Neurology, IRCCS Centro Neurolesi Bonino-Pulejo, Messina, Italy
| | - Luisa Vinciguerra
- Department of Neurology, IRCCS Centro Neurolesi Bonino-Pulejo, Messina, Italy
| | - Francesco Fisicaro
- Department of Surgical Sciences and Advanced Technologies, University of Catania, Italy
| | - Carla Vagli
- Department of Surgical Sciences and Advanced Technologies, University of Catania, Italy
| | - Rita Bella
- Department of Surgical Sciences and Advanced Technologies, University of Catania, Italy
| | - Giovanni Pennisi
- Department of Surgery and Medical-Surgical Specialties, University of Catania, Italy
| | - Vincenzo Di Lazzaro
- Research Unit of Neurology, Neurophysiology and Neurobiology, Università Campus Bio-Medico, Rome, Italy
| | - Manuela Pennisi
- Department of Biomedical and Biotechnological Sciences, University of Catania, Italy
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Cantone M, Lanza G, Le Pira A, Barone R, Pennisi G, Bella R, Pennisi M, Fiumara A. Adjunct Diagnostic Value of Transcranial Magnetic Stimulation in Mucopolysaccharidosis-Related Cervical Myelopathy: A Pilot Study. Brain Sci 2019; 9:brainsci9080200. [PMID: 31416150 PMCID: PMC6721402 DOI: 10.3390/brainsci9080200] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/05/2019] [Accepted: 08/10/2019] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Cervical myelopathy (CM) is a common cause of morbidity and disability in patients with mucopolysaccharidosis (MPS) and, therefore, early detection is crucial for the best surgical intervention and follow-up. Transcranial magnetic stimulation (TMS) non-invasively evaluates the conduction through the cortico-spinal tract, also allowing preclinical diagnosis and monitoring. METHODS Motor evoked potentials (MEPs) to TMS were recorded in a group of eight patients with MPS-related CM. Responses were obtained during mild tonic muscular activation by means of a circular coil held on the "hot spot" of the first dorsal interosseous and tibialis anterior muscles, bilaterally. The motor latency by cervical or lumbar magnetic stimulation was subtracted from the MEP cortical latency to obtain the central motor conduction time. The MEP amplitude from peak to peak to cortical stimulation and the interside difference of each measure were also calculated. RESULTS TMS revealed abnormal findings from both upper and lower limbs compatible with axonal damage and demyelination in six of them. Notably, a subclinical cervical spinal disease was detected before the occurrence of an overt CM in two patients, whereas TMS signs compatible with a CM of variable degree persisted despite surgery in all treated subjects. CONCLUSIONS TMS can be viewed as an adjunct diagnostic test pending further rigorous investigations.
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Affiliation(s)
- Mariagiovanna Cantone
- Department of Neurology, Sant'Elia Hospital, ASP Caltanissetta, Via Luigi Russo 6, 93100 Caltanissetta, Italy
| | - Giuseppe Lanza
- Department of Surgery and Medical-Surgical Specialties, University of Catania, Via Santa Sofia 78, 95125 Catania, Italy.
- Department of Neurology IC, Oasi Research Institute-IRCCS, Via Conte Ruggero 73, 94018 Troina, Italy.
| | - Alice Le Pira
- Referral Center for Inherited Metabolic Diseases, Department of Clinical and Experimental Medicine, University of Catania. Via Santa Sofia 78, 95125 Catania, Italy
| | - Rita Barone
- Child Neurology and Psychiatry, Department of Clinical and Experimental Medicine, University of Catania, Via Santa Sofia 78, 95125 Catania, Italy
| | - Giovanni Pennisi
- Department of Surgery and Medical-Surgical Specialties, University of Catania, Via Santa Sofia 78, 95125 Catania, Italy
| | - Rita Bella
- Department of Medical and Surgical Sciences and Advanced Technologies, Section of Neurosciences, University of Catania, Via Santa Sofia 78, 95125 Catania, Italy
| | - Manuela Pennisi
- Department of Biological and Biotechnological Sciences, University of Catania, Via Santa Sofia 78, 95125 Catania, Italy
| | - Agata Fiumara
- Referral Center for Inherited Metabolic Diseases, Department of Clinical and Experimental Medicine, University of Catania. Via Santa Sofia 78, 95125 Catania, Italy
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Adjunct Diagnostic Value of Transcranial Magnetic Stimulation in Mucopolysaccharidosis-Related Cervical Myelopathy: A Pilot Study. Brain Sci 2019. [PMID: 31416150 DOI: 10.3390/brainsci9080200.] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Cervical myelopathy (CM) is a common cause of morbidity and disability in patients with mucopolysaccharidosis (MPS) and, therefore, early detection is crucial for the best surgical intervention and follow-up. Transcranial magnetic stimulation (TMS) non-invasively evaluates the conduction through the cortico-spinal tract, also allowing preclinical diagnosis and monitoring. METHODS Motor evoked potentials (MEPs) to TMS were recorded in a group of eight patients with MPS-related CM. Responses were obtained during mild tonic muscular activation by means of a circular coil held on the "hot spot" of the first dorsal interosseous and tibialis anterior muscles, bilaterally. The motor latency by cervical or lumbar magnetic stimulation was subtracted from the MEP cortical latency to obtain the central motor conduction time. The MEP amplitude from peak to peak to cortical stimulation and the interside difference of each measure were also calculated. RESULTS TMS revealed abnormal findings from both upper and lower limbs compatible with axonal damage and demyelination in six of them. Notably, a subclinical cervical spinal disease was detected before the occurrence of an overt CM in two patients, whereas TMS signs compatible with a CM of variable degree persisted despite surgery in all treated subjects. CONCLUSIONS TMS can be viewed as an adjunct diagnostic test pending further rigorous investigations.
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Cantone M, Lanza G, Vinciguerra L, Puglisi V, Ricceri R, Fisicaro F, Vagli C, Bella R, Ferri R, Pennisi G, Di Lazzaro V, Pennisi M. Age, Height, and Sex on Motor Evoked Potentials: Translational Data From a Large Italian Cohort in a Clinical Environment. Front Hum Neurosci 2019. [PMID: 31214003 DOI: 10.3389/fnhum.2019.00185.] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Introduction Motor evoked potentials (MEPs) to transcranial magnetic stimulation (TMS) are known to be susceptible to several sources of variability. However, conflicting evidences on individual characteristics in relatively small sample sizes have been reported. We investigated the effect of age, height, and sex on MEPs of the motor cortex and spinal roots in a large cohort. Methods A total of 587 subjects clinically and neuroradiologically intact were included. MEPs were recorded during mild tonic contraction through a circular coil applied over the "hot spot" of the first dorsal interosseous and tibialis anterior muscles (TAs), bilaterally. Central motor conduction time (CMCT) was estimated as the difference between MEP cortical latency and the peripheral motor conduction time (PMCT) by cervical or lumbar magnetic stimulation. Peak-to-peak MEP amplitude to cortical stimulation and right-to-left difference of each parameter were also measured. Results After Bonferroni correction, general linear (multiple) regression analysis showed that both MEP cortical latency and PMCT at four limbs positively correlated with age and height. At lower limbs, an independent effect of sex on the same measures was also observed (with females showing smaller values than males). CMCT correlated with both age (negatively) and height (positively) when analyzed by a single regression; however, with a multiple regression analysis this significance disappeared, due to the correction for the multicollinearity within the dataset. Conclusion Physical individual features need to be considered for a more accurate and meaningful MEPs interpretation. Both in clinical practice and in research setting, patients and controls should be matched for age, height, and sex.
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Affiliation(s)
- Mariagiovanna Cantone
- Department of Neurology, Sant'Elia Hospital, ASP Caltanissetta, Caltanissetta, Italy
| | - Giuseppe Lanza
- Department of Surgery and Medical-Surgical Specialties, University of Catania, Catania, Italy.,Department of Neurology IC, Oasi Research Institute - IRCCS, Troina, Italy
| | - Luisa Vinciguerra
- Department of Neurology and Stroke Unit, IRCCS Centro Neurolesi Bonino Pulejo, Messina, Italy
| | - Valentina Puglisi
- Department of Neurology and Stroke Unit, IRCCS Centro Neurolesi Bonino Pulejo, Messina, Italy
| | - Riccardo Ricceri
- Department of Internal Medicine, Sant'Anna Hospital, AUSL Reggio Emilia, Castelnovo ne' Monti, Italy
| | - Francesco Fisicaro
- Department of Medical and Surgical Sciences and Advanced Technologies, University of Catania, Catania, Italy
| | - Carla Vagli
- Department of Medical and Surgical Sciences and Advanced Technologies, University of Catania, Catania, Italy
| | - Rita Bella
- Department of Medical and Surgical Sciences and Advanced Technologies, University of Catania, Catania, Italy
| | - Raffaele Ferri
- Department of Neurology IC, Oasi Research Institute - IRCCS, Troina, Italy
| | - Giovanni Pennisi
- Department of Surgery and Medical-Surgical Specialties, University of Catania, Catania, Italy
| | - Vincenzo Di Lazzaro
- Research Unit of Neurology, Neurophysiology and Neurobiology, Università Campus Bio-Medico, Rome, Italy
| | - Manuela Pennisi
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
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Cantone M, Lanza G, Vinciguerra L, Puglisi V, Ricceri R, Fisicaro F, Vagli C, Bella R, Ferri R, Pennisi G, Di Lazzaro V, Pennisi M. Age, Height, and Sex on Motor Evoked Potentials: Translational Data From a Large Italian Cohort in a Clinical Environment. Front Hum Neurosci 2019; 13:185. [PMID: 31214003 PMCID: PMC6558095 DOI: 10.3389/fnhum.2019.00185] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Accepted: 05/20/2019] [Indexed: 02/05/2023] Open
Abstract
INTRODUCTION Motor evoked potentials (MEPs) to transcranial magnetic stimulation (TMS) are known to be susceptible to several sources of variability. However, conflicting evidences on individual characteristics in relatively small sample sizes have been reported. We investigated the effect of age, height, and sex on MEPs of the motor cortex and spinal roots in a large cohort. METHODS A total of 587 subjects clinically and neuroradiologically intact were included. MEPs were recorded during mild tonic contraction through a circular coil applied over the "hot spot" of the first dorsal interosseous and tibialis anterior muscles (TAs), bilaterally. Central motor conduction time (CMCT) was estimated as the difference between MEP cortical latency and the peripheral motor conduction time (PMCT) by cervical or lumbar magnetic stimulation. Peak-to-peak MEP amplitude to cortical stimulation and right-to-left difference of each parameter were also measured. RESULTS After Bonferroni correction, general linear (multiple) regression analysis showed that both MEP cortical latency and PMCT at four limbs positively correlated with age and height. At lower limbs, an independent effect of sex on the same measures was also observed (with females showing smaller values than males). CMCT correlated with both age (negatively) and height (positively) when analyzed by a single regression; however, with a multiple regression analysis this significance disappeared, due to the correction for the multicollinearity within the dataset. CONCLUSION Physical individual features need to be considered for a more accurate and meaningful MEPs interpretation. Both in clinical practice and in research setting, patients and controls should be matched for age, height, and sex.
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Affiliation(s)
- Mariagiovanna Cantone
- Department of Neurology, Sant’Elia Hospital, ASP Caltanissetta, Caltanissetta, Italy
| | - Giuseppe Lanza
- Department of Surgery and Medical-Surgical Specialties, University of Catania, Catania, Italy
- Department of Neurology IC, Oasi Research Institute – IRCCS, Troina, Italy
- *Correspondence: Giuseppe Lanza, ;
| | - Luisa Vinciguerra
- Department of Neurology and Stroke Unit, IRCCS Centro Neurolesi Bonino Pulejo, Messina, Italy
| | - Valentina Puglisi
- Department of Neurology and Stroke Unit, IRCCS Centro Neurolesi Bonino Pulejo, Messina, Italy
| | - Riccardo Ricceri
- Department of Internal Medicine, Sant’Anna Hospital, AUSL Reggio Emilia, Castelnovo ne’ Monti, Italy
| | - Francesco Fisicaro
- Department of Medical and Surgical Sciences and Advanced Technologies, University of Catania, Catania, Italy
| | - Carla Vagli
- Department of Medical and Surgical Sciences and Advanced Technologies, University of Catania, Catania, Italy
| | - Rita Bella
- Department of Medical and Surgical Sciences and Advanced Technologies, University of Catania, Catania, Italy
| | - Raffaele Ferri
- Department of Neurology IC, Oasi Research Institute – IRCCS, Troina, Italy
| | - Giovanni Pennisi
- Department of Surgery and Medical-Surgical Specialties, University of Catania, Catania, Italy
| | - Vincenzo Di Lazzaro
- Research Unit of Neurology, Neurophysiology and Neurobiology, Università Campus Bio-Medico, Rome, Italy
| | - Manuela Pennisi
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
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What is the functional relevance of reorganization in primary motor cortex after spinal cord injury? Neurobiol Dis 2019; 121:286-295. [DOI: 10.1016/j.nbd.2018.09.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 09/10/2018] [Indexed: 01/15/2023] Open
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Potter-Baker KA, Janini DP, Lin YL, Sankarasubramanian V, Cunningham DA, Varnerin NM, Chabra P, Kilgore KL, Richmond MA, Frost FS, Plow EB. Transcranial direct current stimulation (tDCS) paired with massed practice training to promote adaptive plasticity and motor recovery in chronic incomplete tetraplegia: A pilot study. J Spinal Cord Med 2018; 41:503-517. [PMID: 28784042 PMCID: PMC6117576 DOI: 10.1080/10790268.2017.1361562] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
OBJECTIVE Our goal was to determine if pairing transcranial direct current stimulation (tDCS) with rehabilitation for two weeks could augment adaptive plasticity offered by these residual pathways to elicit longer-lasting improvements in motor function in incomplete spinal cord injury (iSCI). DESIGN Longitudinal, randomized, controlled, double-blinded cohort study. SETTING Cleveland Clinic Foundation, Cleveland, Ohio, USA. PARTICIPANTS Eight male subjects with chronic incomplete motor tetraplegia. INTERVENTIONS Massed practice (MP) training with or without tDCS for 2 hrs, 5 times a week. OUTCOME MEASURES We assessed neurophysiologic and functional outcomes before, after and three months following intervention. Neurophysiologic measures were collected with transcranial magnetic stimulation (TMS). TMS measures included excitability, representational volume, area and distribution of a weaker and stronger muscle motor map. Functional assessments included a manual muscle test (MMT), upper extremity motor score (UEMS), action research arm test (ARAT) and nine hole peg test (NHPT). RESULTS We observed that subjects receiving training paired with tDCS had more increased strength of weak proximal (15% vs 10%), wrist (22% vs 10%) and hand (39% vs. 16%) muscles immediately and three months after intervention compared to the sham group. Our observed changes in muscle strength were related to decreases in strong muscle map volume (r=0.851), reduced weak muscle excitability (r=0.808), a more focused weak muscle motor map (r=0.675) and movement of weak muscle motor map (r=0.935). CONCLUSION Overall, our results encourage the establishment of larger clinical trials to confirm the potential benefit of pairing tDCS with training to improve the effectiveness of rehabilitation interventions for individuals with SCI. TRIAL REGISTRATION NCT01539109.
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Affiliation(s)
- Kelsey A. Potter-Baker
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio, USA,Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veteran’s Affairs, Cleveland, Ohio, USA
| | - Daniel P. Janini
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio, USA
| | - Yin-Liang Lin
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio, USA
| | | | - David A. Cunningham
- Kessler Foundation, Human Performance & Engineering Laboratory, West Orange, New Jersey, USA
| | - Nicole M. Varnerin
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio, USA
| | - Patrick Chabra
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio, USA
| | - Kevin L. Kilgore
- Functional Electrical Stimulation Center, Louis Stokes Cleveland Department of Veteran’s Affairs, Cleveland, Ohio, USA,Department of Orthopaedics, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA,Department of Orthopaedics, MetroHealth Medical Center, Cleveland, Ohio, USA
| | - Mary Ann Richmond
- Spinal Cord Injury and Disorders Service, Louis Stokes Cleveland Department of Veteran’s Affairs, Cleveland, Ohio, USA,Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Frederick S. Frost
- Department of Physical Medicine and Rehabilitation, Neurological Institute, Cleveland Clinic Foundation, Cleveland, Ohio, USA
| | - Ela B. Plow
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio, USA,Department of Physical Medicine and Rehabilitation, Neurological Institute, Cleveland Clinic Foundation, Cleveland, Ohio, USA,Center for Neurological Restoration, Neurosurgery, Neurological Institute, Cleveland Clinic Foundation, Cleveland, Ohio, USA,Correspondence to: Ela B. Plow Assistant Staff, Department of Biomedical Engineering, Assistant Professor, Cleveland Clinic Lerner College of Medicine, Cleveland Clinic Foundation, 9500 Euclid Ave., ND20 Cleveland, OH 44195, USA; Ph: 216-445-4589, Fax: 216-444-9198;
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Matamala JM, Nuñez C, Verdugo RJ, Lera L, Sánchez H, Albala C, Castillo JL. Vitamin B12 status does not influence central motor conduction time in asymptomatic elderly people: a transcranial magnetic stimulation study. Somatosens Mot Res 2014; 31:136-40. [PMID: 24694205 DOI: 10.3109/08990220.2014.897603] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
INTRODUCTION Vitamin B12 deficiency causes neurologic and psychiatric disease, especially in older adults. Subacute combined degeneration is characterized by damage to the posterior and lateral spinal cord affecting the corticospinal tract. OBJECTIVE To test corticospinal tract projections using motor evoked potentials (MEPs) by transcranial magnetic stimulation (TMS) in asymptomatic older adults with low vitamin B12 (B12) levels. METHODS Cross-sectional study of 53 healthy older adults (>70 years). MEPs were recorded in the abductor pollicis brevis and tibialis anterior muscles, at rest and during slight tonic contraction. Central motor conduction time (CMCT) was derived from the latency of MEPs and peripheral motor conduction time (PMCT). Neurophysiological variables were analyzed statistically according to B12 status. RESULTS Median age was 74.3 ± 3.6 years (58.5% women). Twenty-six out of the 53 subjects had low vitamin B12 levels (B12 < 221 pmol/l). MEPs were recorded for all subjects in upper and lower extremities. There were no significant differences in either latency or amplitude of MEPs and CMCT between low and normal B12 groups. There was a significant PMCT delay in the lower extremities in the low B12 group (p = 0.014). CONCLUSIONS No subclinical abnormality of the corticospinal tract is detected in asymptomatic B12-deficient older adults. The peripheral nervous system appears to be more vulnerable to damage attributable to this vitamin deficit. The neurophysiological evaluation of asymptomatic older adults with lower B12 levels should be focused mainly in peripheral nervous system evaluation.
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Affiliation(s)
- José Manuel Matamala
- Department of Neurological Science, Faculty of Medicine, University of Chile , Santiago , Chile and
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Matamala JM, Núñez C, Lera L, Verdugo RJ, Sánchez H, Albala C, Castillo JL. Motor evoked potentials by transcranial magnetic stimulation in healthy elderly people. Somatosens Mot Res 2013; 30:201-5. [PMID: 23767989 DOI: 10.3109/08990220.2013.796922] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
INTRODUCTION Transcranial magnetic stimulation (TMS) is a non-invasive, safe, and painless method for evaluating the corticospinal pathway. The population of older adults is growing, along with the prevalence of neurological diseases common to this group. Latency and amplitude of motor evoked potentials (MEPs) vary among healthy subjects and no reference normal values for MEPs in healthy older adults are available. OBJECTIVE To create a reference value for MEPs by TMS for healthy older adults. METHODS Descriptive study in 36 healthy 70-year-old and older subjects. A 90-mm circular coil Magstim® magnetic stimulator was applied over Cz and Fz. Recording was done in the abductor pollicis brevis and tibialis anterior muscles, at rest and during sustained tonic contraction. Central motor conduction time (CMCT) was derived from MEP latency and peripheral motor conduction time (PMCT). Values were related to age, gender, standing height, and knee height. RESULTS Mean age was 73.3 ± 2.4 years (58% female). In the upper extremity, average MEP latency was 23.3 ± 1.9 ms at rest and 19.9 ± 1.9 ms during tonic contraction. In the lower extremity, average MEP latency was 30.6 ± 2.5 ms at rest and 27.2 ± 2.3 ms during tonic contraction. There was a significant correlation between MEP latency and standing height, greater in the lower extremities. Female gender appeared as an independent factor determining lower MEP latency, but not CMCT, in upper and lower extremities. CONCLUSION We have provided clinically useful reference values for MEPs by TMS in healthy adults older than 70 years of age. As in the younger population, standing height is important in defining normal MEPs. The difference between genders might be due to the lower height of women.
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Affiliation(s)
- José Manuel Matamala
- Department of Neurological Science, Faculty of Medicine, University of Chile , Santiago , Chile and
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21
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Bunday KL, Perez MA. Motor recovery after spinal cord injury enhanced by strengthening corticospinal synaptic transmission. Curr Biol 2012. [PMID: 23200989 DOI: 10.1016/j.cub.2012.10.046] [Citation(s) in RCA: 152] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The corticospinal tract is an important target for motor recovery after spinal cord injury (SCI) in animals and humans. Voluntary motor output depends on the efficacy of synapses between corticospinal axons and spinal motoneurons, which can be modulated by the precise timing of neuronal spikes. Using noninvasive techniques, we developed tailored protocols for precise timing of the arrival of descending and peripheral volleys at corticospinal-motoneuronal synapses of an intrinsic finger muscle in humans with chronic incomplete SCI. We found that arrival of presynaptic volleys prior to motoneuron discharge enhanced corticospinal transmission and hand voluntary motor output. The reverse order of volley arrival and sham stimulation did not affect or decreased voluntary motor output and electrophysiological outcomes. These findings are the first demonstration that spike timing-dependent plasticity of residual corticospinal-motoneuronal synapses provides a mechanism to improve motor function after SCI. Modulation of residual corticospinal-motoneuronal synapses may present a novel therapeutic target for enhancing voluntary motor output in motor disorders affecting the corticospinal tract.
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Affiliation(s)
- Karen L Bunday
- Department of Physical Medicine and Rehabilitation, Center for the Neural Basis of Cognition, and Systems Neuroscience Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA
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Plasticity of corticospinal neural control after locomotor training in human spinal cord injury. Neural Plast 2012; 2012:254948. [PMID: 22701805 PMCID: PMC3373155 DOI: 10.1155/2012/254948] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 04/09/2012] [Accepted: 04/10/2012] [Indexed: 12/18/2022] Open
Abstract
Spinal lesions substantially impair ambulation, occur generally in young and otherwise healthy individuals, and result in devastating effects on quality of life. Restoration of locomotion after damage to the spinal cord is challenging because axons of the damaged neurons do not regenerate spontaneously. Body-weight-supported treadmill training (BWSTT) is a therapeutic approach in which a person with a spinal cord injury (SCI) steps on a motorized treadmill while some body weight is removed through an upper body harness. BWSTT improves temporal gait parameters, muscle activation patterns, and clinical outcome measures in persons with SCI. These changes are likely the result of reorganization that occurs simultaneously in supraspinal and spinal cord neural circuits. This paper will focus on the cortical control of human locomotion and motor output, spinal reflex circuits, and spinal interneuronal circuits and how corticospinal control is reorganized after locomotor training in people with SCI. Based on neurophysiological studies, it is apparent that corticospinal plasticity is involved in restoration of locomotion after training. However, the neural mechanisms underlying restoration of lost voluntary motor function are not well understood and translational neuroscience research is needed so patient-orientated rehabilitation protocols to be developed.
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Abstract
The corticospinal tract (CST) is a major descending pathway contributing to the control of voluntary movement in mammals. During the last decades anatomical and electrophysiological studies have demonstrated significant reorganization in the CST after spinal cord injury (SCI) in animals and humans. In animal models of SCI, anatomical evidence showed corticospinal sprouts rostral and caudal to the lesion and their integration into intraspinal axonal circuits. Electrophysiological data suggested that indirect connections from the primary motor cortex to forelimb motoneurons, via brainstem nuclei and spinal cord interneurons, or direct connections from slow uninjured corticospinal axons, might contribute to the control of movement after a CST injury. In humans with SCI, post mortem spinal cord tissue revealed anatomical changes in the CST some of which were similar but others markedly different from those found in animal models of SCI. Human electrophysiological studies have provided ample evidence for corticospinal reorganization after SCI that may contribute to functional recovery. Together these studies have revealed a large plastic capacity of the CST after SCI. There is also a limited understanding of the relationship between anatomical and electrophysiological changes in the CST and control of movement after SCI. Increasing our knowledge of the role of CST plasticity in functional restoration after SCI may support the development of more effective repair strategies.
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Affiliation(s)
- Martin Oudega
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, 4074 BST3, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA.
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Leukel C, Taube W, Beck S, Schubert M. Pathway-specific plasticity in the human spinal cord. Eur J Neurosci 2012; 35:1622-9. [DOI: 10.1111/j.1460-9568.2012.08067.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
Background. The description of the natural course of recovery from a spinal cord injury (SCI) with spontaneous improvement of neurological, neurophysiological, and functional measures is an important prerequisite in appraising effects of upcoming interventional therapies. Objective. To describe the spontaneous evolution of motor-evoked potentials of the anterior tibial muscle (TA-MEP) and their relation to outcomes of lower extremity motor scores (LEMS) and walking function in patients recovering from an acute SCI. Methods. TA-MEPs were assessed in 255 SCI subjects within 5 time intervals throughout the first year after SCI with combined neurological and functional measures. Tibial nerve conduction studies were performed to screen for peripheral nerve damage. Results. TA-MEP allowed stratification of SCI according to lesion severity and outcome. As MEP amplitudes increased over 12 months after SCI, this was paralleled by a significant improvement of LEMS and walking function. TA-MEP latencies remained usually stable. Conclusion. Clinical outcome and walking function after SCI can be predicted independent of clinical measures by assessment of TA-MEP reflecting corticospinal tract integrity.
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Affiliation(s)
- Jens A. Petersen
- University Hospital Zurich, Zurich, Switzerland
- University Hospital Balgrist, Zurich, Switzerland
| | | | - Armin Curt
- University Hospital Balgrist, Zurich, Switzerland
| | - Volker Dietz
- University Hospital Balgrist, Zurich, Switzerland
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26
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Cao Q, Whittemore SR. Cell transplantation: stem cells and precursor cells. HANDBOOK OF CLINICAL NEUROLOGY 2012; 109:551-61. [PMID: 23098736 DOI: 10.1016/b978-0-444-52137-8.00034-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Stem cells have been used to approach four different therapeutic repair strategies in spinal cord injury (SCI): (1) replacement of lost neurons, (2) replacement of oligodendrocytes to promote remyelination of demyelinated and/or regenerated axons, (3) providing a permissive substrate for axonal regeneration to overcome the intrinsic inhibition of surface molecules, and (4) engendering host repair. The first two strategies involve cell-specific differentiation of engrafted neural cells and the latter two may involve grafted neural or non-neural cells. The preclinical data for all of these approaches is at times contradictory and there is no consensus as to what type of stem cell is optimal to facilitate repair in specific injuries. Remyelination has been the most successful stem cell replacement strategy. Partial lineage restriction and pharmacological and/or genetic manipulation to express additional trophic support or restrict responses to host signals appears necessary for optimal neuronal and oligodendrocytic differentiation. However, these modifications will make their clinical application exceedingly difficult. Effects of grafted stem cells on abrogating host immune responses and engendering intrinsic repair is also a mechanism through which stem cells are likely therapeutically beneficial. While clinical trials with stem cell grafting into the injured spinal cord are ongoing, preclinical studies have yet to define mechanisms of action that can be definitively translated to those clinical approaches.
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Affiliation(s)
- Qilin Cao
- Department of Neurosurgery, University of Texas Medical School, Houston, TX, USA
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Neurophysiological changes in deformity correction of adolescent idiopathic scoliosis with intraoperative skull-femoral traction. Spine (Phila Pa 1976) 2011; 36:1627-38. [PMID: 21897186 DOI: 10.1097/brs.0b013e318216124e] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Retrospective review of 36 consecutive patients undergoing coronal plane deformity correction with intraoperative skull-femoral traction between 2005 and 2008 with motor evoked potential (MEP)/somatosensory evoked potential monitoring. OBJECTIVE To determine the prevalence and significance of neurophysiological changes with intraoperative skull-femoral traction in adolescent idiopathic scoliosis. SUMMARY OF BACKGROUND DATA Intraoperative skeletal traction can be associated with spinal cord stretching and ischemia with resultant electrophysiological changes. The prevalence and risks of such changes and their clinical significance is unknown. METHODS Thirty-seven procedures involving 36 patients (27 females and 9 males) with a mean age of 14.8 (12-18) years were divided into two groups on the basis of the presence (group 1, n = 18 procedures) or absence (group 2, n = 19) of significant MEP changes with surgery. They were compared with patients undergoing correction without traction (group 3). RESULTS Significant differences among the groups were observed in mean preoperative Cobb angle (86° vs. 70° vs. 59°), mean intraoperative posttraction Cobb angle (50.0° vs. 34.6°), traction index (0.41 vs. 0.50), flexibility index (0.14 vs. 0.27 vs. 0.25), and presence of primary lumbar curves (0% vs. 32% vs. 14%). Initial onset of MEP amplitude loss (group 1) occurred at a mean of 94 (1-257) minutes from the onset of surgery, was bilateral in 13 procedures, and improved at a mean of 5.5 (1-29) minutes after decreasing or removing the traction. At closure, complete bilateral recovery to baseline was observed in 10 procedures, recovery to >50% baseline in five, and recovery to <50% baseline in three procedures. There were no neurologic deficits in this series. CONCLUSION Intraoperative traction is associated with frequent changes in MEP monitoring. The thoracic location of the major curve, increasing Cobb angle, and rigidity of major curve are significant risk factors for changes in MEP with traction. The presence of any MEP recordings irrespective of its amplitude at closure was associated with normal neurological function. Somatosensory evoked potential monitoring did not correlate with the traction induced MEP amplitude changes.
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Barthélemy D, Willerslev-Olsen M, Lundell H, Conway BA, Knudsen H, Biering-Sørensen F, Nielsen JB. Impaired transmission in the corticospinal tract and gait disability in spinal cord injured persons. J Neurophysiol 2010; 104:1167-76. [PMID: 20554839 DOI: 10.1152/jn.00382.2010] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Rehabilitation following spinal cord injury is likely to depend on recovery of corticospinal systems. Here we investigate whether transmission in the corticospinal tract may explain foot drop (inability to dorsiflex ankle) in persons with spinal cord lesion. The study was performed in 24 persons with incomplete spinal cord lesion (C1 to L1) and 15 healthy controls. Coherence in the 10- to 20-Hz frequency band between paired tibialis anterior muscle (TA) electromyographic recordings obtained in the swing phase of walking, which was taken as a measure of motor unit synchronization. It was significantly correlated with the degree of foot drop, as measured by toe elevation and ankle angle excursion in the first part of swing. Transcranial magnetic stimulation was used to elicit motor-evoked potentials (MEPs) in the TA. The amplitude of the MEPs at rest and their latency during contraction were correlated to the degree of foot drop. Spinal cord injured participants who exhibited a large foot drop had little or no MEP at rest in the TA muscle and had little or no coherence in the same muscle during walking. Gait speed was correlated to foot drop, and was the lowest in participants with no MEP at rest. The data confirm that transmission in the corticospinal tract is of importance for lifting the foot during the swing phase of human gait.
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Affiliation(s)
- Dorothy Barthélemy
- Department of Physical Exercise and Sport Sciences, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
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Cao Q, He Q, Wang Y, Cheng X, Howard RM, Zhang Y, DeVries WH, Shields CB, Magnuson DSK, Xu XM, Kim DH, Whittemore SR. Transplantation of ciliary neurotrophic factor-expressing adult oligodendrocyte precursor cells promotes remyelination and functional recovery after spinal cord injury. J Neurosci 2010; 30:2989-3001. [PMID: 20181596 PMCID: PMC2836860 DOI: 10.1523/jneurosci.3174-09.2010] [Citation(s) in RCA: 167] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2009] [Revised: 11/09/2009] [Accepted: 12/26/2009] [Indexed: 12/13/2022] Open
Abstract
Demyelination contributes to the dysfunction after traumatic spinal cord injury (SCI). We explored whether the combination of neurotrophic factors and transplantation of adult rat spinal cord oligodendrocyte precursor cells (OPCs) could enhance remyelination and functional recovery after SCI. Ciliary neurotrophic factor (CNTF) was the most effective neurotrophic factor to promote oligodendrocyte (OL) differentiation and survival of OPCs in vitro. OPCs were infected with retroviruses expressing enhanced green fluorescent protein (EGFP) or CNTF and transplanted into the contused adult thoracic spinal cord 9 d after injury. Seven weeks after transplantation, the grafted OPCs survived and integrated into the injured spinal cord. The survival of grafted CNTF-OPCs increased fourfold compared with EGFP-OPCs. The grafted OPCs differentiated into adenomatus polyposis coli (APC(+)) OLs, and CNTF significantly increased the percentage of APC(+) OLs from grafted OPCs. Immunofluorescent and immunoelectron microscopic analyses showed that the grafted OPCs formed central myelin sheaths around the axons in the injured spinal cord. The number of OL-remyelinated axons in ventrolateral funiculus (VLF) or lateral funiculus (LF) at the injured epicenter was significantly increased in animals that received CNTF-OPC grafts compared with all other groups. Importantly, 75% of rats receiving CNTF-OPC grafts recovered transcranial magnetic motor-evoked potential and magnetic interenlargement reflex responses, indicating that conduction through the demyelinated axons in VLF or LF, respectively, was partially restored. More importantly, recovery of hindlimb locomotor function was significantly enhanced in animals receiving grafts of CNTF-OPCs. Thus, combined treatment with OPC grafts expressing CNTF can enhance remyelination and facilitate functional recovery after traumatic SCI.
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Affiliation(s)
- Qilin Cao
- Kentucky Spinal Cord Injury Research Center, University of Louisville School of Medicine, Louisville, Kentucky 40202, USA.
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Curt A, Van Hedel HJA, Klaus D, Dietz V. Recovery from a spinal cord injury: significance of compensation, neural plasticity, and repair. J Neurotrauma 2008; 25:677-85. [PMID: 18578636 DOI: 10.1089/neu.2007.0468] [Citation(s) in RCA: 211] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Clinical recovery after a lesion of the central nervous system (CNS) can be attributed to mechanisms of functional compensation, neural plasticity, and/or repair. The relative impact of each of these mechanisms after a human spinal cord injury (SCI) has been explored in a prospective European multi-center study in 460 acute traumatic SCI subjects. Functional (activities of daily living and ambulatory capacity), neurological (sensory-motor deficits), and spinal conductivity (motor- and somato-sensory evoked potentials) measures were repeatedly followed over 12 months. In accordance with previous studies, complete SCI subjects (cSCI; n = 217) improved in activities of daily living unrelated to changes of the neurological condition, while incomplete SCI subjects (iSCI; n = 243) showed a greater functional and neurological recovery. The functional recovery in iSCI subjects was not related to an improvement of spinal conductivity, as reflected in unchanged latencies of the evoked potentials. This is in line with animal studies, where spinal conductivity of damaged spinal tracts has been reported to remain unchanged. These findings support the assumption that functional recovery occurs by compensation, especially in cSCI and by neural plasticity leading to a greater improvement in iSCI. Relevant repair of damaged spinal pathways does not take place.
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Affiliation(s)
- Armin Curt
- Spinal Cord Injury Centre, Balgrist University Hospital, Forchstrasse 340, Zurich, Switzerland
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31
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Figueroa JD, Benton RL, Velazquez I, Torrado AI, Ortiz CM, Hernandez CM, Diaz JJ, Magnuson DS, Whittemore SR, Miranda JD. Inhibition of EphA7 up-regulation after spinal cord injury reduces apoptosis and promotes locomotor recovery. J Neurosci Res 2007; 84:1438-51. [PMID: 16983667 DOI: 10.1002/jnr.21048] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Functional impairment after spinal cord injury (SCI) is partially attributed to neuronal cell death, with further degeneration caused by the accompanying apoptosis of myelin-forming oligodendrocytes. The Eph receptor protein tyrosine kinase family and its cognate ligands, the ephrins, have been identified to be involved in axonal outgrowth, synapse formation, and target recognition, mainly mediated by repulsive activity. Recent reports suggest that ephrin/Eph signaling might also play a role as a physiological trigger for apoptosis during embryonic development. Here, we investigated the expression profile of EphA7, after SCI, by using a combination of quantitative real-time PCR (QRT-PCR) and immunohistochemical techniques. QRT-PCR analysis showed an increase in the expression of full-length EphA7 at 7 days postinjury (DPI). Receptor immunoreactivity was shown mostly in astrocytes of the white matter at the injury epicenter. In control animals, EphA7 expression was observed predominantly in motor neurons of the ventral gray matter, although some immunoreactivity was seen in white matter. Furthermore, blocking the expression of EphA7 after SCI using antisense oligonucleotides resulted in significant acceleration of hindlimb locomotor recovery at 1 week. This was a transient effect; by 2 weeks postinjury, treated animals were not different from controls. Antisense treatment also produced a return of nerve conduction, with shorter latencies than in control treated animals after transcranial magnetic stimulation. We identified EphA7 receptors as putative regulators of apoptosis in the acute phase after SCI. These results suggest a functional role for EphA7 receptors in the early stages of SCI pathophysiology.
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Affiliation(s)
- Johnny D Figueroa
- Department of Physiology, University of Puerto Rico Medical Science Campus, San Juan, Puerto Rico
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Enzmann GU, Benton RL, Talbott JF, Cao Q, Whittemore SR. Functional considerations of stem cell transplantation therapy for spinal cord repair. J Neurotrauma 2006; 23:479-95. [PMID: 16629631 DOI: 10.1089/neu.2006.23.479] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Stem cells hold great promise for therapeutic repair after spinal cord injury (SCI). This review compares the current experimental approaches taken towards a stem cell-based therapy for SCI. It critically evaluates stem cell sources, injury paradigms, and functional measurements applied to detect behavioral changes after transplantation into the spinal cord. Many of the documented improvements do not exclusively depend on lineage-specific cellular differentiation. In most of the studies, the functional tests used cannot unequivocally demonstrate how differentiation of the transplanted cells contributes to the observed effects. Standardized cell isolation and transplantation protocols could facilitate the assessment of the true contribution of various experimental parameters on recovery. We conclude that at present embryonic stem (ES)-derived cells hold the most promise for therapeutic utility, but that non-neural cells may ultimately be optimal if the mechanism of possible transdifferentiation can be elucidated.
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Affiliation(s)
- Gaby U Enzmann
- Kentucky Spinal Cord Injury Research Center, Louisville, Kentucky 40202, USA
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Cao Q, Xu XM, Devries WH, Enzmann GU, Ping P, Tsoulfas P, Wood PM, Bunge MB, Whittemore SR. Functional recovery in traumatic spinal cord injury after transplantation of multineurotrophin-expressing glial-restricted precursor cells. J Neurosci 2006; 25:6947-57. [PMID: 16049170 PMCID: PMC2813488 DOI: 10.1523/jneurosci.1065-05.2005] [Citation(s) in RCA: 237] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Demyelination contributes to the physiological and behavioral deficits after contusive spinal cord injury (SCI). Therefore, remyelination may be an important strategy to facilitate repair after SCI. We show here that rat embryonic day 14 spinal cord-derived glial-restricted precursor cells (GRPs), which differentiate into both oligodendrocytes and astrocytes, formed normal-appearing central myelin around axons of cultured DRG neurons and had enhanced proliferation and survival in the presence of neurotrophin 3 (NT3) and brain-derived neurotrophin factor (BDNF). We infected GRPs with retroviruses expressing the multineurotrophin D15A (with both BDNF and NT3 activities) and then transplanted them into the contused adult thoracic spinal cord at 9 d after injury. Expression of D15A in the injured spinal cord is five times higher in animals receiving D15A-GRP grafts than ones receiving enhanced green fluorescent protein (EGFP)-GRP or DMEM grafts. Six weeks after transplantation, the grafted GRPs differentiated into mature oligodendrocytes expressing both myelin basic protein (MBP) and adenomatus polyposis coli (APC). Ultrastructural analysis showed that the grafted GRPs formed morphologically normal-appearing myelin sheaths around the axons in the ventrolateral funiculus (VLF) of spinal cord. Expression of D15A significantly increased the percentage of APC+ oligodendrocytes of grafted GRPs (15-30%). Most importantly, 8 of 12 rats receiving grafts of D15A-GRPs recovered transcranial magnetic motor-evoked potential responses, indicating that conduction through the demyelinated VLF axons was restored. Such electrophysiological recovery was not observed in rats receiving grafts of EGFP-GRPs, D15A-NIH3T3 cells, or an injection of an adenovirus expressing D15A. Recovery of hindlimb locomotor function was also significantly enhanced only in the D15A-GRP-grafted animals at 4 and 5 weeks after transplantation. Therefore, combined treatment with neurotrophins and GRP grafts can facilitate functional recovery after traumatic SCI and may prove to be a useful therapeutic strategy to repair the injured spinal cord.
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Affiliation(s)
- Qilin Cao
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, Kentucky 40202, USA
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McKay WB, Lee DC, Lim HK, Holmes SA, Sherwood AM. Neurophysiological examination of the corticospinal system and voluntary motor control in motor-incomplete human spinal cord injury. Exp Brain Res 2004; 163:379-87. [PMID: 15616810 DOI: 10.1007/s00221-004-2190-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2004] [Accepted: 10/06/2004] [Indexed: 10/26/2022]
Abstract
This study employed neurophysiological methods to relate the condition of the corticospinal system with the voluntary control of lower-limb muscles in persons with motor-incomplete spinal cord injury. It consisted of two phases. In a group of ten healthy subjects, single and paired transcranial magnetic stimulation (TMS) of the motor cortex was used to study the behavior of the resulting motor evoked potentials (MEP) in lower-limb muscles. Interstimulus intervals (ISIs) of 15-100 ms were examined for augmentation of test MEPs by threshold or subthreshold conditioning stimuli. The second phase of this study examined eight incomplete spinal cord injured (iSCI) subjects, American Spinal Injury Association Impairment Scale C (n = 5) and D (n = 3) in whom voluntary motor control was quantified using the surface EMG (sEMG) based Voluntary Response Index (VRI). The VRI is calculated to characterize relative output patterns across ten lower-limb muscles recorded during a standard protocol of elementary voluntary motor tasks. VRI components were calculated by comparing the distribution of sEMG in iSCI subjects with prototype patterns collected from 15 healthy subjects using the same rigidly administered protocol, The resulting similarity index (SI) and magnitude values provided the measure of voluntary motor control. Corticospinal system connections were characterized by the thresholds for MEPs in key muscles. Key muscles were those that function as the prime-movers, or agonists for the voluntary movements from which the VRI data were calculated. Results include healthy-subject data that showed significant increases in conditioned MEP responses with paired stimuli of 15-50 ms ISI. Stimulus pairs of 75 and 100 ms showed no increase in MEP peak amplitude over that of the single-pulse conditioning stimulus alone, usually no response. For the iSCI subjects, 42% of the agonists responded to single-pulse TMS and 25% required paired-pulse TMS to produce an MEP. American Spinal Injury Association Impairment Scale component motor scores for agonist muscles, Quadriceps, Tibialis Anterior, and Triceps Surae, were significantly lower where MEPs could not be obtained (p < 0.05). VRI values were also significantly lower for motor tasks with agonists that had no resting MEP (p < 0.01). Therefore, the presence of a demonstrable connection between the motor cortex and spinal motor neurons in persons with SCI was related to the quality of post-injury voluntary motor control as assessed by the VRI.
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Affiliation(s)
- W B McKay
- Baylor College of Medicine, Houston, TX, USA
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Abstract
PURPOSE To determine the reliability of motor-evoked potentials (MEP) obtained using transcranial magnetic stimulation (TMS) in the first dorsal interosseous (FDI) and biceps brachii muscles. METHODS Fourteen college subjects attended the laboratory on three separate days. TMS was used to obtain MEP with the subject relaxed (resting condition) at stimulation intensities of 70%, 85%, and 100% of maximal stimulator output. MEP were also obtained during four active contraction conditions involving contractions of 25%, 50%, 75%, and 100% of maximal effort (MVC). Reliability was measured using an intraclass correlation analysis of variance (ANOVA) design. RESULTS In the resting condition, substantial increases in MEP amplitude were observed for both muscles from day 1 to day 2. Intraclass reliability estimates were higher for the biceps muscle (ICC = 0.95-0.99) than for the FDI muscle (ICC = 0.60-0.81). During the active conditions, the greatest MEP were observed at 25% and 50% MVC, with smaller MEP at 75% and 100% MVC. Intraclass correlations in the active condition were approximately 0.63-0.73. CONCLUSIONS : Moderate to good reliability of MEP amplitude in the biceps and FDI muscles can be obtained using TMS in both resting and active contraction conditions.
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Affiliation(s)
- Gary Kamen
- Department of Exercise Science, University of Massachusetts-Amherst, Amherst, MA 01003-9258, USA.
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Iles JF, Ali AS, Savic G. Vestibular-evoked muscle responses in patients with spinal cord injury. Brain 2004; 127:1584-92. [PMID: 15128616 DOI: 10.1093/brain/awh173] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The vestibular system was activated by galvanic electrical stimulation in 22 patients with spinal cord injury. Three patients were studied standing and all were studied sitting. Electromyographic responses recorded in soleus (standing patients) and the erectores spinae (all patients) were compared with data from 18 control subjects. The vestibular stimulus polarity and head position were arranged so as to produce excitatory medium latency muscle responses in the controls. Responses in the patient group were present bilaterally, present unilaterally or absent below the level of injury. The amplitude of response recorded in erectores spinae at lumbar levels below the lesion in 21 patients (left and right side responses summed) and five control subjects was positively correlated with American Spinal Injuries Association (ASIA) grade: the smallest amplitudes were found in patients with the most severe impairment (Spearman rank correlation coefficient rs = 0.59; P = 0.002, two-tailed). The latency of response (averaged for both sides) was negatively correlated with ASIA grade in 21 patients: the longest latencies were found in patients with the most severe impairment (rs = -0.57; P < 0.01, two-tailed). Amplitude and latency were negatively correlated (rs = -0.72, P < 0.002, two-tailed). The latencies of responses recorded in the erectores spinae at different vertebral levels were linearly related to the vertical distance from the inion to the recording site in both patient and control groups. The conduction velocities of the spinal pathways activated by vestibular stimulation were 4.6 and 10.4 m/s in patient (recording below lesion) and control groups, respectively. Both clinical status (patients recording below lesion, patients recording above lesion and controls) and distance were significant predictors of latency (general linear model, P < 0.0005). It is concluded that measurement of vestibular-evoked responses could provide information on the level and density of spinal cord lesions.
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Affiliation(s)
- J F Iles
- Department of Zoology, University of Oxford, UK.
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Knikou M, Rymer WZ. Hip angle induced modulation of H reflex amplitude, latency and duration in spinal cord injured humans. Clin Neurophysiol 2002; 113:1698-708. [PMID: 12417222 DOI: 10.1016/s1388-2457(02)00285-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVES To investigate the modulation of the soleus H reflex in spinal cord injured (SCI) subjects resulting from imposed changes in hip angle and to establish whether changes in H reflex amplitude co-vary with changes in reflex latency and duration. METHODS H reflexes were recorded using conventional methods in 7 SCI subjects in the supine position. The right leg was secured by a leg brace and positioned at various angles of hip flexion (30 degrees, 40 degrees ) and at 10 degrees of hip extension. RESULTS We found that imposing 10 degrees of hip extension resulted in a significant facilitation in the size of the soleus H reflex in all of the SCI subjects tested (200% of control reflex; recorded at 10 degrees of hip flexion). In contrast, positioning the hip at 30 degrees and at 40 degrees of flexion resulted in a significant reduction of the H reflex in 6 of 7 SCI subjects tested. In the remaining subject, an increase in the H reflex amplitude was observed. Modulation of H reflex amplitude coincided with shifts in both H reflex latency and duration. The reflex latency was prolonged when the reflex amplitude was reduced following hip flexion, while hip extension shortened the reflex latency. In contrast, the H reflex duration was prolonged with hip extended and shortened with hip flexed. CONCLUSIONS When changes in static hip joint position are imposed in SCI subjects, changes in afferent feedback from hip proprioceptors are capable of promoting a switch between excitatory and inhibitory pathways. Associated changes in H reflex latency and duration are consistent with the hypothesis that oligosynaptic inputs contribute to the hip angle-induced H reflex modulation. Possible mechanisms for these effects are discussed.
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Affiliation(s)
- Maria Knikou
- Department of Physical Medicine and Rehabilitation, Feinberg School of Medicine, Northwestern University, 345 East Superior, Room 1406, Chicago, IL 60611, USA.
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Ioannides AA, Liu L, Khurshudyan A, Bodley R, Poghosyan V, Shibata T, Dammers J, Jamous A. Brain activation sequences following electrical limb stimulation of normal and paraplegic subjects. Neuroimage 2002; 16:115-29. [PMID: 11969323 DOI: 10.1006/nimg.2002.1065] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In current clinical practice the degree of paraplegia or quadriplegia is objectively determined with transcranial magnetic stimulation (TMS) and somatosensory-evoked potentials (SSEP). We measured the MEG signal following electrical stimulation of upper and lower limbs in two normal and three clinically complete paraplegic subjects. From the MEG signal we computed distributed estimates of brain activity and identified foci just behind the central sulcus consistent in location with primary somatosensory (SI) for arm and foot and secondary somatosensory (SII) areas. Activation curves were computed from regions of interest defined around these areas. Activation of the SI foot area was observed in normal and paraplegic subjects when the upper limb was stimulated. Surprisingly, for each paraplegic subject, stimulation below the lesion was followed by cortical activations. These activations were weak, only loosely time-locked to the stimulus and were seen intermittently behind the central sulcus and nearby cortical areas. Statistical analysis of tomographic solutions and activation curves showed consistent responses following foot stimulation in one paraplegic (PS1) and intermittently in another paraplegic subject. We repeated the same experiment for PS1 in a different laboratory and the results from the analysis of foot stimulation from both laboratories revealed statistically significant focal cortical response only in the contralateral SI foot area.
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Affiliation(s)
- Andreas A Ioannides
- Laboratory for Human Brain Dynamics, Brain Science Institute (BSI), RIKEN, 2-1 Hirosawa, Wako-shi, Saitama, 351-0198, Japan
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Calancie B, Alexeeva N, Broton JG, Suys S, Hall A, Klose KJ. Distribution and latency of muscle responses to transcranial magnetic stimulation of motor cortex after spinal cord injury in humans. J Neurotrauma 1999; 16:49-67. [PMID: 9989466 DOI: 10.1089/neu.1999.16.49] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Noninvasive transcranial magnetic stimulation (TMS) of the motor cortex was used to evoke electromyographic (EMG) responses in persons with spinal cord injury (n = 97) and able-bodied subjects (n = 20, for comparative data). Our goal was to evaluate, for different levels and severity of spinal cord injury, potential differences in the distribution and latency of motor responses in a large sample of muscles affected by the injury. The spinal cord injury (SCI) population was divided into subgroups based upon injury location (cervical, thoracic, and thoracolumbar) and clinical status (motor-complete versus motor-incomplete). Cortical stimuli were delivered while subjects attempted to contract individual muscles, in order to both maximize the probability of a response to TMS and minimize the response latency. Subjects with motor-incomplete injuries to the cervical or thoracic spinal cord were more likely to demonstrate volitional and TMS-evoked contractions in muscles controlling their foot and ankle (i.e., distal lower limb muscles) compared to muscles of the thigh (i.e., proximal lower limb muscles). When TMS did evoke responses in muscles innervated at levels caudal to the spinal cord lesion, response latencies of muscles in the lower limbs were delayed equally for persons with injury to the cervical or thoracic spinal cord, suggesting normal central motor conduction velocity in motor axons caudal to the lesion. In fact, motor response distribution and latencies were essentially indistinguishable for injuries to the cervical or thoracic (at or rostral to T10) levels of the spine. In contrast, motor-incomplete SCI subjects with injuries at the thoracolumbar level showed a higher probability of preserved volitional movements and TMS-evoked contractions in proximal muscles of the lower limb, and absent responses in distal muscles. When responses to TMS were seen in this group, the latencies were not significantly longer than those of able-bodied (AB) subjects, strongly suggestive of "root sparing" as a basis for motor function in subjects with injury at or caudal to the T11 vertebral body. Both the distribution and latency of TMS-evoked responses are consistent with highly focal lesions to the spinal cord in the subjects examined. The pattern of preserved responsiveness predominating in the distal leg muscles is consistent with a greater role of corticospinal tract innervation of these muscles compared to more proximal muscles of the thigh and hip.
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Affiliation(s)
- B Calancie
- Miami Project to Cure Paralysis and Department of Neurological Surgery, University of Miami School of Medicine, Florida 33136, USA
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