scholarly journals Common neural structures activated by epidural and transcutaneous lumbar spinal cord stimulation: Elicitation of posterior root-muscle reflexes

PLoS ONE ◽  
2018 ◽  
Vol 13 (1) ◽  
pp. e0192013 ◽  
Author(s):  
Ursula S. Hofstoetter ◽  
Brigitta Freundl ◽  
Heinrich Binder ◽  
Karen Minassian
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Stimulation ◽  
Lumbar Spinal Cord ◽  
Posterior Root ◽  
Lumbar Spinal ◽  
Muscle Reflexes

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 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.

Lipomeningocele associated with diplomyelia in a dog

2018 ◽  
Vol 46 (05) ◽  
pp. 323-329 ◽  
Author(s):  
Nele Ondreka ◽  
Sara Malberg ◽  
Emma Laws ◽  
Martin Schmidt ◽  
Sabine Schulze
Keyword(s):  
Spinal Cord ◽  
Neurological Status ◽  
Split Cord Malformation ◽  
Lumbar Spinal Cord ◽  
Histopathological Diagnosis ◽  
Type I ◽  
Thoracic Spinal Cord ◽  
Thoracic Spinal ◽  
Subcutaneous Mass ◽  
Lumbar Spinal

SummaryA 2-year-old male neutered mixed breed dog with a body weight of 30 kg was presented for evaluation of a soft subcutaneous mass on the dorsal midline at the level of the caudal thoracic spine. A further clinical sign was intermittent pain on palpation of the area of the subcutaneous mass. The owner also described a prolonged phase of urination with repeated interruption and re-initiation of voiding. The findings of the neurological examination were consistent with a lesion localization between the 3rd thoracic and 3rd lumbar spinal cord segments. Magnetic resonance imaging revealed a spina bifida with a lipomeningocele and diplomyelia (split cord malformation type I) at the level of thoracic vertebra 11 and 12 and secondary syringomyelia above the aforementioned defects in the caudal thoracic spinal cord. Surgical resection of the lipomeningocele via a hemilaminectomy was performed. After initial deterioration of the neurological status postsurgery with paraplegia and absent deep pain sensation the dog improved within 2 weeks to non-ambulatory paraparesis with voluntary urination. Six weeks postoperatively the dog was ambulatory, according to the owner. Two years after surgery the owner recorded that the dog showed a normal gait, a normal urination and no pain. Histopathological diagnosis of the biopsied material revealed a lipomeningocele which confirmed the radiological diagnosis.

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