Flexion reflex modulation during stepping in human spinal cord injury

2009 ◽  
Vol 196 (3) ◽  
pp. 341-351 ◽  
Author(s):  
Maria Knikou ◽  
Claudia A. Angeli ◽  
Christie K. Ferreira ◽  
Susan J. Harkema
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Reflex Modulation ◽  
Human Spinal Cord ◽  
Flexion Reflex ◽  
Cord Injury

Windup of Flexion Reflexes in Chronic Human Spinal Cord Injury: A Marker for Neuronal Plateau Potentials?

2003 ◽  
Vol 89 (1) ◽  
pp. 416-426 ◽  
Author(s):  
T. G. Hornby ◽  
W. Z. Rymer ◽  
E. N. Benz ◽  
B. D. Schmit
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Reflex Response ◽  
Electromyographic Activity ◽  
Plateau Potentials ◽  
Physiological Basis ◽  
Human Spinal Cord ◽  
Reflex Responses ◽  
Flexion Reflex ◽  
Cord Injury

The physiological basis of flexion spasms in individuals after spinal cord injury (SCI) may involve alterations in the properties of spinal neurons in the flexion reflex pathways. We hypothesize that these changes would be manifested as progressive increases in reflex response with repetitive stimulus application (i.e., “windup”) of the flexion reflexes. We investigated the windup of flexion reflex responses in 12 individuals with complete chronic SCI. Flexion reflexes were triggered using trains of electrical stimulation of plantar skin at variable intensities and inter-stimulus intervals. For threshold and suprathreshold stimulation, windup of both peak ankle and hip flexion torques and of integrated tibialis anterior electromyographic activity was observed consistently in all patients at inter-stimulus intervals ≤3 s. For subthreshold stimuli, facilitation of reflexes occurred only at intervals ≤1 s. Similarly, the latency of flexion reflexes decreased significantly at intervals ≤1 s. Patients that were receiving anti-spasticity medications (e.g., baclofen) had surprisingly larger windup of reflex responses than those who did not take such medications, although this difference may be related to differences of spasm frequency between the groups of subjects. The results indicate that the increase in spinal neuronal excitability following a train of electrical stimuli lasts for ≤3 s, similar to previous studies of nociceptive processing. Such long-lasting increases in flexion reflex responses suggest that cellular mechanisms such as plateau potentials in spinal motoneurons, interneurons, or both, may partially mediate spinal cord hyperexcitability in the absence of descending modulatory input.

Plantar Cutaneous Afferents Normalize the Reflex Modulation Patterns During Stepping in Chronic Human Spinal Cord Injury

2010 ◽  
Vol 103 (3) ◽  
pp. 1304-1314 ◽  
Author(s):  
Maria Knikou
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Pulse Train ◽  
H Reflex ◽  
Cutaneous Afferents ◽  
Reflex Modulation ◽  
Flexion Reflex ◽  
Long Latency ◽  
Cord Injury ◽  
Foot Sole Stimulation

Plantar cutaneous afferent transmission is critical for recovery of locomotion in spinalized animals, whereas a phase-dependent reflex modulation is apparent during fictive or real locomotion. In nine people with a chronic spinal cord injury (SCI) the effects of foot sole stimulation on the soleus H-reflex and tibialis anterior (TA) flexion reflex modulation patterns during assisted stepping were established on different days. The soleus H-reflex was elicited by posterior tibial nerve stimulation followed by a supramaximal stimulus 100 ms after the test H-reflex to control for movement of recording electrodes. The flexion reflex was evoked by sural nerve stimulation with a 30-ms pulse train, recorded from the ipsilateral TA muscle, and elicited at 1.2- to twofold the reflex threshold. During assisted stepping, spinal reflexes were conditioned by percutaneous stimulation of the ipsilateral metatarsals at threefold perceptual threshold with a 20-ms pulse train delivered at 9- to 11-ms conditioning-test intervals. Stimuli were randomly dispersed across the step cycle, which was divided into 16 equal bins. The conditioned soleus H-reflex was significantly facilitated at midstance and depressed during midswing when compared with the unconditioned soleus H-reflex recorded during stepping. Foot sole stimulation induced a significant facilitation of the long-latency TA flexion reflex before, during, and after stance-to-swing transition when compared with the unconditioned long-latency TA flexion reflex during stepping. This study provides evidence that plantar cutaneous afferents remarkably influence the soleus H-reflex and TA flexion reflex modulation patterns during stepping and support that actions of plantar cutaneous afferents onto spinal interneuronal circuits engaged in locomotion are manifested in a phase-dependent manner in chronic SCI subjects.

scholarly journals Modulation of flexion reflex induced by hip angle changes in human spinal cord injury

2005 ◽  
Vol 168 (4) ◽  
pp. 577-586 ◽  
Author(s):  
Maria Knikou ◽  
Elizabeth Kay ◽  
William Zev Rymer
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Human Spinal Cord ◽  
Flexion Reflex ◽  
Cord Injury

scholarly journals Impaired Organization of Paired-Pulse TMS-Induced I-Waves After Human Spinal Cord Injury

2015 ◽  
Vol 26 (5) ◽  
pp. 2167-2177 ◽  
Author(s):  
John Cirillo ◽  
Finnegan J. Calabro ◽  
Monica A. Perez
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Paired Pulse ◽  
Human Spinal Cord ◽  
Cord Injury

The effects of methylprednisolone and the ganglioside GM1 on acute spinal cord injury in rats

1994 ◽  
Vol 80 (1) ◽  
pp. 97-111 ◽  
Author(s):  
Shlomo Constantini ◽  
Wise Young
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Body Weight Loss ◽  
Ganglioside Gm1 ◽  
Rat Spinal Cord ◽  
Neuroprotective Effects ◽  
Content Type ◽  
Human Spinal Cord ◽  
Cord Injury ◽  
Fine Print

✓ Recent clinical trials have reported that methylprednisolone sodium succinate (MP) or the monosialic ganglioside GM1 improves neurological recovery in human spinal cord injury. Because GM1 may have additive or synergistic effects when used with MP, the authors compared MP, GM1, and MP+GM1 treatments in a graded rat spinal cord contusion model. Spinal cord injury was caused by dropping a rod weighing 10 gm from a height of 1.25, 2.5, or 5.0 cm onto the rat spinal cord at T-10, which had been exposed via laminectomy. The lesion volumes were quantified from spinal cord Na and K shifts at 24 hours after injury and the results were verified histologically in separate experiments. A single dose of MP (30 mg/kg), given 5 minutes after injury, reduced 24-hour spinal cord lesion volumes by 56% (p = 0.0052), 28% (p = 0.0065), and 13% (p > 0.05) in the three injury-severity groups, respectively, compared to similarly injured control groups treated with vehicle only. Methylprednisolone also prevented injury-induced hyponatremia and increased body weight loss in the spine-injured rats. When used alone, GM1 (10 to 30 mg/kg) had little or no effect on any measured variable compared to vehicle controls; when given concomitantly with MP, GM1 blocked the neuroprotective effects of MP. At a dose of 3 mg/kg, GM1 partially prevented MP-induced reductions in lesion volumes, while 10 to 30 mg/kg of GM1 completely blocked these effects of MP. The effects of MP on injury-induced hyponatremia and body weight loss were also blocked by GM1. Thus, GM1 antagonized both central and peripheral effects of MP in spine-injured rats. Until this interaction is clarified, the authors recommend that MP and GM1 not be used concomitantly to treat acute human spinal cord injury. Because GM1 modulates protein kinase activity, protein kinases inhibit lipocortins, and lipocortins mediate anti-inflammatory effects of glucocorticoids, it is proposed that the neuroprotective effects of MP are partially due to anti-inflammatory effects and that GM1 antagonizes the effects of MP by inhibiting lipocortin. Possible beneficial effects of GM1 reported in central nervous system injury may be related to the effects on neural recovery rather than acute injury processes.

scholarly journals Safety and Feasibility of Autologous Olfactory Ensheathing Cell and Bone Marrow Mesenchymal Stem Cell Co-transplantation in Chronic Human Spinal Cord Injury: A Clinical Trial

2021 ◽  
Author(s):  
Homa Zamani ◽  
Mina Soufizomorrod ◽  
Saeed Oraee-Yazdani ◽  
Dariush Naviafar ◽  
Mohammadhosein Akhlaghpasand ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Bone Marrow ◽  
Spinal Cord Injury ◽  
Stem Cell ◽  
Mesenchymal Stem Cell ◽  
Safety Issue ◽  
Functional Evaluation ◽  
Olfactory Ensheathing Cell ◽  
Human Spinal Cord ◽  
Cord Injury

Abstract Cell-based therapies are considered as promising strategies for spinal cord regeneration. However, a combinatorial cell therapeutic approach seems more beneficial as it can target various aspects of the injury. Here, we assessed the safety and feasibility of autologous mucosal Olfactory Ensheathing Cell (OEC) and bone marrow Mesenchymal Stem Cell (MSC) co-transplantation in patients with chronic, complete (American Spinal Injury Association (ASIA) classification A) Spinal Cord Injury (SCI). Three patients with the traumatic SCI of the thoracic level were enrolled. They received autologous OEC and MSC combination through the lumbar puncture. All adverse events and possible functional outcomes were documented performing pre- and post-operative general clinical examination, Magnetic Resonance Imaging (MRI), neurological assessment based on the International Standard of Neurological Classification for SCI (ISNCSCI), and functional evaluation using Spinal Cord Independence Measure version III (SCIM III). No serious safety issue was recorded during the two years of follow-up. MRI findings remained unchanged with no neoplastic tissue formation. ASIA impairment scale improved from A to B in one of the participants. SCIM III evaluation also showed some degrees of progress in this patient's quality of life. The two other patients had negligible or no improvement in their sensory scores without any changes in the ASIA impairment scale and SCIM III scores. No motor recovery was observed in any of the participants. Overall, this two-year trial was not associated with any adverse findings, which may suggest the safety of autologous OEC and bone marrow MSC combination for the treatment of human SCI.This study was registered at the Iranian Registry of Clinical Trials (IRCT registration number: IRCT20160110025930N2/ registration date: 2018-09-29).

scholarly journals Motoneuron Death after Human Spinal Cord Injury

2017 ◽  
Vol 34 (3) ◽  
pp. 581-590 ◽  
Author(s):  
Robert M. Grumbles ◽  
Christine K. Thomas
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Human Spinal Cord ◽  
Cord Injury
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