scholarly journals Influence of Spine Curvature on the Efficacy of Transcutaneous Lumbar Spinal Cord Stimulation

2021 ◽  
Vol 10 (23) ◽  
pp. 5543
Author(s):  
Veronika E. Binder ◽  
Ursula S. Hofstoetter ◽  
Anna Rienmüller ◽  
Zoltán Száva ◽  
Matthias J. Krenn ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Stimulation ◽  
Thoracolumbar Spine ◽  
Lower Limbs ◽  
Lumbar Spinal Cord ◽  
Specific Effects ◽  
Afferent Fibers ◽  
Lumbar Spinal ◽  
Transcutaneous Spinal Cord Stimulation ◽  
Spinal Flexion

Transcutaneous spinal cord stimulation is a non-invasive method for neuromodulation of sensorimotor function. Its main mechanism of action results from the activation of afferent fibers in the posterior roots—the same structures as targeted by epidural stimulation. Here, we investigated the influence of sagittal spine alignment on the capacity of the surface-electrode-based stimulation to activate these neural structures. We evaluated electromyographic responses evoked in the lower limbs of ten healthy individuals during extension, flexion, and neutral alignment of the thoracolumbar spine. To control for position-specific effects, stimulation in these spine alignment conditions was performed in four different body positions. In comparison to neutral and extended spine alignment, flexion of the spine resulted in a strong reduction of the response amplitudes. There was no such effect on tibial-nerve evoked H reflexes. Further, there was a reduction of post-activation depression of the responses to transcutaneous spinal cord stimulation evoked in spinal flexion. Thus, afferent fibers were reliably activated with neutral and extended spine alignment. Spinal flexion, however, reduced the capacity of the stimulation to activate afferent fibers and led to the co-activation of motor fibers in the anterior roots. This change of action was due to biophysical rather than neurophysiological influences. We recommend applying transcutaneous spinal cord stimulation in body positions that allow individuals to maintain a neutral or extended spine.

scholarly journals Simultaneous Cervical and Lumbar Spinal Cord Stimulation Induces Facilitation of Both Spinal and Corticospinal Circuitry in Humans

2021 ◽  
Vol 15 ◽  
Author(s):  
Behdad Parhizi ◽  
Trevor S. Barss ◽  
Vivian K. Mushahwar
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Stimulation ◽  
Motor Evoked Potential ◽  
H Reflex ◽  
Spinal Reflex ◽  
Lumbar Spinal Cord ◽  
Reflex Amplitude ◽  
Leg Cycling ◽  
Lumbar Spinal ◽  
Neurologically Intact

Coupling between cervical and lumbar spinal networks (cervico-lumbar coupling) is vital during human locomotion. Impaired cervico-lumbar coupling after neural injuries or diseases can be reengaged via simultaneous arm and leg cycling training. Sensorimotor circuitry including cervico-lumbar coupling may further be enhanced by non-invasive modulation of spinal circuity using transcutaneous spinal cord stimulation (tSCS). This project aimed to determine the effect of cervical, lumbar, or combined tSCS on spinal reflex (Hoffmann [H-]) and corticospinal (motor evoked potential [MEP]) excitability during a static or cycling cervico-lumbar coupling task. Fourteen neurologically intact study participants were seated in a recumbent leg cycling system. H-reflex and MEP amplitudes were assessed in the left flexor carpi radialis (FCR) muscle during two tasks (Static and Cycling) and four conditions: (1) No tSCS, (2) tSCS applied to the cervical enlargement (Cervical); (3) tSCS applied to the lumbar enlargement (Lumbar); (4) simultaneous cervical and lumbar tSCS (Combined). While cervical tSCS did not alter FCR H-reflex amplitude relative to No tSCS, lumbar tSCS significantly facilitated H-reflex amplitude by 11.1%, and combined cervical and lumbar tSCS significantly enhanced the facilitation to 19.6%. Neither cervical nor lumbar tSCS altered MEP amplitude alone (+4.9 and 1.8% relative to legs static, No tSCS); however, combined tSCS significantly increased MEP amplitude by 19.7% compared to No tSCS. Leg cycling alone significantly suppressed the FCR H-reflex relative to static, No tSCS by 13.6%, while facilitating MEP amplitude by 18.6%. When combined with leg cycling, tSCS was unable to alter excitability for any condition. This indicates that in neurologically intact individuals where interlimb coordination and corticospinal tract are intact, the effect of leg cycling on cervico-lumbar coupling and corticospinal drive was not impacted significantly with the tSCS intensity used. This study demonstrates, for the first time, that tonic activation of spinal cord networks through multiple sites of tSCS provides a facilitation of both spinal reflex and corticospinal pathways. It remains vital to determine if combined tSCS can influence interlimb coupling after neural injury or disease when cervico-lumbar connectivity is impaired.

scholarly journals A Spinal Arteriovenous Fistula in a 3-Year Old Boy

2014 ◽  
Vol 2014 ◽  
pp. 1-4
Author(s):  
Thomas E. M. Crijnen ◽  
Sandra van Gijlswijk ◽  
Jozef De Dooy ◽  
Maurits H. J. Voormolen ◽  
Dominique Robert ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Family History ◽  
Arteriovenous Fistula ◽  
Epidural Haematoma ◽  
Lower Limbs ◽  
Venous Aneurysm ◽  
Lumbar Spinal Cord ◽  
Mri Scan ◽  
Spinal Arteriovenous Fistula ◽  
Lumbar Spinal

We present a case of a 3-year-old boy with neurodegeneration. Family history reveals Rendu-Osler-Weber disease. Magnetic resonance imaging (MRI) of the spinal cord and spinal angiography showed a spinal arteriovenous fistula with venous aneurysm, causing compression of the lumbar spinal cord. Embolisation of the fistula was executed, resulting in clinical improvement. A week after discharge he was readmitted with neurologic regression. A second MRI scan revealed an intraspinal epidural haematoma and increase in size of the aneurysm with several new arterial feeders leading to it. Coiling of the aneurysm and fistulas was performed. Postoperative, the spinal oedema increased despite corticoids, causing more extensive paraplegia of the lower limbs and a deterioration of his mental state. A laminectomy was performed and the aneurysm was surgically removed. Subsequently, the boy recovered gradually. A new MRI scan after two months showed less oedema and a split, partly affected spinal chord. This case shows the importance of excluding possible arteriovenous malformations in a child presenting with progressive neurodegeneration. In particular when there is a family history for Rendu-Osler-Weber disease, scans should be performed instantly to rule out this possibility. The case also highlights the possibility of good recovery of paraplegia in paediatric Rendu-Osler-Weber patients.

Afferent Fibers of the Hypogastric Nerves Are Involved in the Facilitating Effects of Chemical Bladder Irritation in Rats

2001 ◽  
Vol 86 (5) ◽  
pp. 2276-2284 ◽  
Author(s):  
Takahiko Mitsui ◽  
Hidehiro Kakizaki ◽  
Shinobu Matsuura ◽  
Kaname Ameda ◽  
Mitsuhiro Yoshioka ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Acetic Acid ◽  
Marked Decrease ◽  
Lumbar Spinal Cord ◽  
Urinary Frequency ◽  
Acid Infusion ◽  
Afferent Fibers ◽  
Fos Expression ◽  
Lumbar Spinal

To evaluate the role of bladder afferent fibers in the hypogastric nerves (HGN) in modulation of the micturition reflex induced by chemical bladder irritation, voiding behavior, continuous cystometry, and spinal c-fos expression following intravesical acetic acid instillation were investigated in rats with or without HGN transection. Voiding behavior and continuous cystometry were examined in unanesthetized conscious rats. Following chemical bladder irritation, a significant increase in urinary frequency associated with a marked decrease in the voided volume per micturition, was noted in control rats with the intact HGN, but not in HGN-transected rats. Continuous infusion of acetic acid in control rats elicited irritative bladder responses characterized by a marked decrease in the intercontraction interval and a marked increase in maximal vesical pressure, both of which were absent in capsaicin-desensitized rats. HGN transection prevented the decrease in the intercontraction interval but not an increase in maximal vesical pressure following chemical bladder irritation. Compared with saline infusion, acetic acid infusion caused a significant increase in c-fos expression at L1 and L6 of the spinal cord, and HGN transection significantly reduced c-fos expression in the dorsal horn of the spinal cord at L1 but not at L6. These results suggest that capsaicin-sensitive bladder afferent fibers in the HGN, which travel through the rostral lumbar spinal cord, have a role in urinary frequency caused by chemical bladder irritation.

ATP P2× Receptors and Sensory Synaptic Transmission Between Primary Afferent Fibers and Spinal Dorsal Horn Neurons in Rats

1998 ◽  
Vol 80 (6) ◽  
pp. 3356-3360 ◽  
Author(s):  
Ping Li ◽  
Amelita A. Calejesan ◽  
Min Zhuo
Keyword(s):  
Spinal Cord ◽  
Synaptic Transmission ◽  
Dorsal Horn ◽  
Lumbar Spinal Cord ◽  
Superficial Dorsal Horn ◽  
Primary Afferent ◽  
Dorsal Horn Neurons ◽  
Afferent Fibers ◽  
Primary Afferent Fibers ◽  
Lumbar Spinal

Li, Ping, Amelita A. Calean, and Min Zhuo. ATP P2× receptors and sensory synaptic transmission between primary afferent fibers and spinal dorsal horn neurons in rats. J. Neurophysiol. 80: 3356–3360, 1998. Glutamate is a major fast transmitter between primary afferent fibers and dorsal horn neurons in the spinal cord. Recent evidence indicates that ATP acts as another fast transmitter at the rat cervical spinal cord and is proposed to serve as a transmitter for nociception and pain. Sensory synaptic transmission between dorsal root afferent fibers and neurons in the superficial dorsal horn of the lumbar spinal cord were examined by whole cell patch-clamp recording techniques. Experiments were designed to test if ATP could serve as a transmitter at the lumbar spinal cord. Monosynaptic excitatory postsynaptic currents (EPSCs) were completely abolished after the blockade of both glutamatergic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/kainate and N-methyl-d-aspartate receptors. No residual current was detected, indicating that glutamate but not ATP is a fast transmitter at the dorsal horn of the lumbar spinal cord. Pyridoxal-phosphate-6-azophenyl-2′,4′-disulfonic acid (PPADS), a selective P2× receptor antagonist, produced an inhibitory modulatory effect on fast EPSCs and altered responses to paired-pulse stimulation, suggesting the involvement of a presynaptic mechanism. Intrathecal administration of PPADS did not produce any antinociceptive effect in two different types of behavioral nociceptive tests. The present results suggest that ATP P2×2 receptors modulate excitatory synaptic transmission in the superficial dorsal horn of the lumbar spinal cord by a presynaptic mechanism, and such a mechanism does not play an important role in behavioral responses to noxious heating. The involvement of other P2× subtype receptors, which is are less sensitive to PPADS, in acute nociceptive modulation and persistent pain remains to be investigated.

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