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1.
J Urol ; 211(2): 294-304, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37930962

RESUMEN

PURPOSE: Transcutaneous spinal cord stimulation (TSCS) is a novel neuromodulation modality developed to promote functional restoration in patients with neurological injury or disease. Previous pilot data suggest that lower urinary tract dysfunction (LUTD) due to stroke may be partially alleviated by TSCS. In this study, we examine the mechanism of this effect by evaluating bladder-related brain activity in patients before and after TSCS therapy and comparing it to healthy volunteers. MATERIALS AND METHODS: Patients who developed storage LUTD after a stroke and healthy volunteers without LUTD were recruited. Patients and healthy volunteers underwent simultaneous urodynamics and functional MRI. Patients then completed 24 biweekly sessions of TSCS and underwent another simultaneous urodynamics-functional MRI study. Clinical outcomes were assessed using validated questionnaires and voiding diary. RESULTS: Fifteen patients and 16 healthy volunteers completed the study. Following TSCS, patients exhibited increased blood-oxygen-level-dependent activity in areas including periaqueductal grey, the insula, the lateral prefrontal cortex, and motor cortex. Prior to TSCS therapy, healthy controls exhibited higher blood-oxygen-level-dependent activity in 17 regions, including multiple regions in the prefrontal cortex and basal ganglia. These differences were attenuated after TSCS with no frontal brain differences remaining between healthy volunteers and stroke participants who completed therapy. Neuroimaging changes were complemented by clinically significant improvements in questionnaire scores and voiding diary parameters. CONCLUSIONS: TSCS therapy modulated bladder-related brain activity, reducing differences between healthy volunteers and stroke patients with LUTD. These changes, alongside improved clinical outcomes, suggest TSCS as a promising approach for LUTD management.


Asunto(s)
Síntomas del Sistema Urinario Inferior , Estimulación de la Médula Espinal , Accidente Cerebrovascular , Humanos , Micción/fisiología , Proyectos Piloto , Síntomas del Sistema Urinario Inferior/etiología , Síntomas del Sistema Urinario Inferior/terapia , Síntomas del Sistema Urinario Inferior/diagnóstico , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/terapia , Encéfalo/diagnóstico por imagen , Oxígeno
2.
J Neurophysiol ; 126(5): 1635-1641, 2021 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-34644129

RESUMEN

In intact and spinal-injured anesthetized animals, stimulation levels that did not induce any visible muscle twitches were used to elicit motor evoked potentials (MEPs) of varying amplitude, reflecting the temporal and amplitude dynamics of the background excitability of spinal networks. To characterize the physiological excitability states of neuronal networks driving movement, we designed five experiments in awake rats chronically implanted with an epidural stimulating interface, with and without a spinal cord injury (SCI). First, an uninjured rat at rest underwent a series of single electrical pulses at sub-motor threshold intensity, which generated responses that were continuously recorded from flexor and extensor hindlimb muscles, showing an intrinsic patterned modulation of MEPs. Responses were recruited by increasing strengths of stimulation, and the amplitudes were moderately correlated between flexors and extensors. Next, after SCI, four awake rats at rest showed electrically induced MEPs, varying largely in amplitude, of both flexors and extensors that were mainly synchronously modulated. After full anesthesia, MEP amplitudes were largely reduced, although stimulation still generated random baseline changes, unveiling an intrinsic stochastic modulation. The present five cases demonstrate a methodology that can be feasibly replicated in a broader group of awake and behaving rats to further define experimental treatments involving neuroplasticity. Besides validating a new technology for a neural stimulating interface, the present data support the broader message that there is intrinsic patterned and stochastic modulation of baseline excitability reflecting the dynamics of physiological states of spinal networks.NEW & NOTEWORTHY Chronic implants of a new epidural stimulating interface trace dynamics of spinal excitability in awake rats, before and after injury. Motor evoked potentials induced by trains of pulses at sub-motor threshold intensity were continuously modulated in amplitude. Oscillatory patterns of amplitude modulation reduced with increasing strengths of stimulation and were replaced by an intrinsic stochastic tone under anesthesia. Variability of baseline excitability is a fundamental feature of spinal networks, affecting their responses to external input.


Asunto(s)
Potenciales Evocados Motores/fisiología , Red Nerviosa/fisiología , Traumatismos de la Médula Espinal/fisiopatología , Estimulación de la Médula Espinal , Médula Espinal/fisiología , Anestesia , Animales , Conducta Animal/fisiología , Modelos Animales de Enfermedad , Electromiografía , Ratas
3.
J Neurophysiol ; 126(6): 1843-1859, 2021 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-34669485

RESUMEN

Spinal cord injury (SCI) commonly results in permanent loss of motor, sensory, and autonomic function. Recent clinical studies have shown that epidural spinal cord stimulation may provide a beneficial adjunct for restoring lower extremity and other neurological functions. Herein, we review the recent clinical advances of lumbosacral epidural stimulation for restoration of sensorimotor function in individuals with motor complete SCI and we discuss the putative neural pathways involved in this promising neurorehabilitative approach. We focus on three main sections: review recent clinical results for locomotor restoration in complete SCI; discuss the contemporary understanding of electrical neuromodulation and signal transduction pathways involved in spinal locomotor networks; and review current challenges of motor system modulation and future directions toward integrative neurorestoration. The current understanding is that initial depolarization occurs at the level of large diameter dorsal root proprioceptive afferents that when integrated with interneuronal and latent residual supraspinal translesional connections can recruit locomotor centers and augment downstream motor units. Spinal epidural stimulation can initiate excitability changes in spinal networks and supraspinal networks. Different stimulation parameters can facilitate standing or stepping, and it may also have potential for augmenting myriad other sensorimotor and autonomic functions. More comprehensive investigation of the mechanisms that mediate the transformation of dysfunctional spinal networks to higher functional states with a greater focus on integrated systems-based control system may reveal the key mechanisms underlying neurological augmentation and motor restoration after severe paralysis.


Asunto(s)
Actividad Motora/fisiología , Rehabilitación Neurológica , Recuperación de la Función/fisiología , Traumatismos de la Médula Espinal/fisiopatología , Traumatismos de la Médula Espinal/rehabilitación , Estimulación de la Médula Espinal , Espacio Epidural , Humanos
4.
J Neurophysiol ; 124(3): 774-780, 2020 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-32755339

RESUMEN

Respiratory dysfunction is one of the most debilitating effects of spinal cord injury (SCI) impacting the quality of life of patients and caregivers. In addition, breathing difficulties impact the rehabilitation routine a patient may potentially undergo. Transcutaneous electrical spinal cord neuromodulation (TESCoN) is a novel approach to reactivate and retrain spinal circuits after paralysis. We demonstrate that acute and chronic TESCoN therapy over the cervical spinal cord positively impacts the breathing and coughing ability in a patient with chronic tetraplegia. ln addition, we show that the improved breathing and coughing ability are not only observed in the presence of TESCoN but persisted for a few days after TESCoN was stopped.NEW & NOTEWORTHY Noninvasive spinal neuromodulation improves breathing and coughing in a patient with severe and complete tetraplegia.


Asunto(s)
Médula Cervical/lesiones , Tos , Cuadriplejía/terapia , Trastornos Respiratorios/terapia , Estimulación de la Médula Espinal , Adulto , Médula Cervical/fisiopatología , Enfermedad Crónica , Tos/fisiopatología , Humanos , Masculino , Cuadriplejía/complicaciones , Cuadriplejía/fisiopatología , Trastornos Respiratorios/etiología
5.
Neurourol Urodyn ; 39(8): 2198-2205, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32761953

RESUMEN

OBJECTIVE: Cerebral stroke is a unique model for studying the role of the brain in lower urinary tract (LUT) control. By its nature, stroke must change the activity of the brain to cause LUT dysfunction. The objective of this study was to describe changes in micturition-related brain activity in patients who develop LUT symptoms (LUTS) after a cerebral stroke. MATERIALS AND METHODS: Healthy controls (HC, n = 10) and patients who developed storage LUTS after a cerebral stroke (n = 7) were recruited. Functional magnetic resonance imaging was used to assess brain activity in each subject. In the task-based block design, blood-oxygen-level-dependent (BOLD) signal was detected during rest, active bladder filling, and bladder voiding. BOLD signal intensity was compared between HCs and stroke subjects during bladder filling, voiding, and voiding initiation. RESULTS: Stroke subjects exhibited higher activity in the periaqueductal gray and cerebellum during bladder filling and bladder voiding. HCs exhibited more intense activity in higher centers, such as the cingulate cortex, motor cortex, and the dorsolateral prefrontal cortex in each of the phases examined. CONCLUSIONS: Subjects with stroke-related LUTS exhibit a specific pattern of brain activity during bladder filling and voiding. There appears to be a greater reliance on primitive centers (cerebellum, midbrain) than in healthy controls during both phases of the micturition cycle. We hypothesize that these findings may reflect loss of connectivity with higher brain centers after a stroke.


Asunto(s)
Encéfalo/fisiopatología , Accidente Cerebrovascular/fisiopatología , Micción/fisiología , Adulto , Encéfalo/diagnóstico por imagen , Mapeo Encefálico , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Proyectos Piloto , Accidente Cerebrovascular/diagnóstico por imagen , Adulto Joven
7.
J Neurophysiol ; 119(4): 1521-1527, 2018 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-29361664

RESUMEN

The lower urinary tract (LUT) may be activated by spinal cord stimulation, but the physiological mapping characteristics of LUT activation with noninvasive transcutaneous spinal cord stimulation (TSCS) are not known. The effects of aging on the contractile properties of the detrusor are also not well understood. Therefore, TSCS was applied over the T10/T11 to L6/L7 spinous processes in adult ( n = 6) and aged ( n = 9) female rhesus macaques. A combination of urodynamic studies and electromyography recordings of the external urethral sphincter (EUS), external anal sphincter (EAS), and pelvic floor muscles was performed. Distinct functional maps were demonstrated for TSCS-evoked detrusor and urethral pressures and for the activation of the EUS, EAS, and pelvic floor muscles. The magnitude of responses for each peripheral target organ was dependent on TSCS location and strength. The strongest detrusor contraction was observed with TSCS at the L1/L2 site in adults and the L3/L4 site in aged subjects. TSCS-evoked bladder pressure at the L1/L2 site was significantly higher for the adults compared with the aged subjects ( P < 0.05). Cumulative normalized TSCS-evoked pressures, calculated for five consecutive sites between the T11/T12 and L3/L4 levels, were significantly lower for aged compared with adult subjects ( P < 0.05). The aged animals also showed a caudal shift for the TSCS site that generated the strongest detrusor contraction. We conclude that natural aging in rhesus macaques is associated with decreased detrusor contractility, a finding of significant translational research relevance as detrusor underactivity is a common occurrence with aging in humans. NEW & NOTEWORTHY Transcutaneous spinal cord stimulation (TSCS) was used to map lower urinary tract function in adult and aged rhesus macaques. Aging was associated with decreased peak pressure responses to TSCS, reduced cumulative normalized evoked bladder pressure responses, and a caudal shift for the site generating the strongest TSCS-induced detrusor contraction. We demonstrate the utility of TSCS as a new diagnostic tool for detrusor contractility assessments and conclude that aging is associated with decreased detrusor contractility in primates.


Asunto(s)
Envejecimiento/fisiología , Canal Anal/fisiología , Estimulación Eléctrica/métodos , Contracción Muscular/fisiología , Músculo Esquelético/fisiología , Médula Espinal/fisiología , Uretra/fisiología , Urodinámica/fisiología , Factores de Edad , Canal Anal/fisiopatología , Animales , Electromiografía , Femenino , Macaca mulatta , Músculo Esquelético/fisiopatología , Diafragma Pélvico/fisiología , Uretra/fisiopatología
8.
J Med Primatol ; 46(6): 359-363, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-28727150

RESUMEN

A female rhesus macaque developed two episodes of generalized convulsions during transcutaneous spinal cord stimulation (TSCS) and urodynamic studies under ketamine anesthesia. The seizures took place in the absence of active TSCS and bladder pressure elevation. Ketamine anesthesia remains the primary risk factor for the convulsions during these experimental procedures.


Asunto(s)
Anestesia/efectos adversos , Anestésicos Disociativos/efectos adversos , Ketamina/efectos adversos , Macaca mulatta , Enfermedades de los Monos/inducido químicamente , Convulsiones/inducido químicamente , Animales , Femenino , Factores de Riesgo , Estimulación de la Médula Espinal , Vejiga Urinaria/diagnóstico por imagen
10.
J Neurophysiol ; 116(1): 98-105, 2016 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-27075538

RESUMEN

We reported previously that both transcutaneous electrical spinal cord stimulation and direct pressure stimulation of the plantar surfaces of the feet can elicit rhythmic involuntary step-like movements in noninjured subjects with their legs in a gravity-neutral apparatus. The present experiments investigated the convergence of spinal and plantar pressure stimulation and voluntary effort in the activation of locomotor movements in uninjured subjects under full body weight support in a vertical position. For all conditions, leg movements were analyzed using electromyographic (EMG) recordings and optical motion capture of joint kinematics. Spinal cord stimulation elicited rhythmic hip and knee flexion movements accompanied by EMG bursting activity in the hamstrings of 6/6 subjects. Similarly, plantar stimulation induced bursting EMG activity in the ankle flexor and extensor muscles in 5/6 subjects. Moreover, the combination of spinal and plantar stimulation exhibited a synergistic effect in all six subjects, eliciting greater motor responses than either modality alone. While the motor responses to spinal vs. plantar stimulation seems to activate distinct but overlapping spinal neural networks, when engaged simultaneously, the stepping responses were functionally complementary. As observed during induced (involuntary) stepping, the most significant modulation of voluntary stepping occurred in response to the combination of spinal and plantar stimulation. In light of the known automaticity and plasticity of spinal networks in absence of supraspinal input, these findings support the hypothesis that spinal and plantar stimulation may be effective tools for enhancing the recovery of motor control in individuals with neurological injuries and disorders.


Asunto(s)
Pierna/fisiología , Locomoción/fisiología , Músculo Esquelético/fisiología , Sensación/fisiología , Médula Espinal/fisiología , Adulto , Fenómenos Biomecánicos , Electromiografía , Humanos , Masculino , Persona de Mediana Edad , Actividad Motora/fisiología , Imagen Óptica , Estimulación Física , Presión , Estimulación Eléctrica Transcutánea del Nervio , Volición , Adulto Joven
11.
J Neurophysiol ; 113(9): 3386-96, 2015 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-25695648

RESUMEN

The spinal cord contains the circuitry to control posture and locomotion after complete paralysis, and this circuitry can be enabled with epidural stimulation [electrical enabling motor control (eEmc)] and/or administration of pharmacological agents [pharmacological enabling motor control (fEmc)] when combined with motor training. We hypothesized that the characteristics of the spinally evoked potentials after chronic administration of both strychnine and quipazine under the influence of eEmc during standing and stepping can be used as biomarkers to predict successful motor performance. To test this hypothesis we trained rats to step bipedally for 7 wk after paralysis and characterized the motor potentials evoked in the soleus and tibialis anterior (TA) muscles with the rats in a non-weight-bearing position, standing and stepping. The middle responses (MRs) to spinally evoked stimuli were suppressed with either or both drugs when the rat was suspended, whereas the addition of either or both drugs resulted in an overall activation of the extensor muscles during stepping and/or standing and reduced the drag duration and cocontraction between the TA and soleus muscles during stepping. The administration of quipazine and strychnine in concert with eEmc and step training after injury resulted in larger-amplitude evoked potentials [MRs and late responses (LRs)] in flexors and extensors, with the LRs consisting of a more normal bursting pattern, i.e., randomly generated action potentials within the bursts. This pattern was linked to more successful standing and stepping. Thus it appears that selected features of the patterns of potentials evoked in specific muscles with stimulation can serve as effective biomarkers and predictors of motor performance.


Asunto(s)
Terapia por Estimulación Eléctrica/métodos , Potenciales Evocados Motores/fisiología , Músculo Esquelético/fisiología , Recuperación de la Función/fisiología , Traumatismos de la Médula Espinal/fisiopatología , Traumatismos de la Médula Espinal/terapia , Animales , Fenómenos Biomecánicos , Modelos Animales de Enfermedad , Electromiografía , Potenciales Evocados Motores/efectos de los fármacos , Femenino , Glicinérgicos/farmacología , Miembro Posterior/inervación , Quipazina/farmacología , Ratas , Ratas Sprague-Dawley , Agonistas de Receptores de Serotonina/farmacología , Estricnina/farmacología , Factores de Tiempo
12.
Brain ; 136(Pt 11): 3362-77, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24103912

RESUMEN

Can lower limb motor function be improved after a spinal cord lesion by re-engaging functional activity of the upper limbs? We addressed this issue by training the forelimbs in conjunction with the hindlimbs after a thoracic spinal cord hemisection in adult rats. The spinal circuitries were more excitable, and behavioural and electrophysiological analyses showed improved hindlimb function when the forelimbs were engaged simultaneously with the hindlimbs during treadmill step-training as opposed to training only the hindlimbs. Neuronal retrograde labelling demonstrated a greater number of propriospinal labelled neurons above and below the thoracic lesion site in quadrupedally versus bipedally trained rats. The results provide strong evidence that actively engaging the forelimbs improves hindlimb function and that one likely mechanism underlying these effects is the reorganization and re-engagement of rostrocaudal spinal interneuronal networks. For the first time, we provide evidence that the spinal interneuronal networks linking the forelimbs and hindlimbs are amenable to a rehabilitation training paradigm. Identification of this phenomenon provides a strong rationale for proceeding toward preclinical studies for determining whether training paradigms involving upper arm training in concert with lower extremity training can enhance locomotor recovery after neurological damage.


Asunto(s)
Terapia por Ejercicio/métodos , Miembro Anterior/fisiología , Miembro Posterior/fisiopatología , Red Nerviosa/fisiopatología , Neuronas/citología , Traumatismos de la Médula Espinal/rehabilitación , Médula Espinal/citología , Animales , Modelos Animales de Enfermedad , Terapia por Ejercicio/instrumentación , Locomoción/fisiología , Propiocepción/fisiología , Ratas , Médula Espinal/patología , Médula Espinal/fisiopatología , Traumatismos de la Médula Espinal/patología , Traumatismos de la Médula Espinal/fisiopatología , Vértebras Torácicas/lesiones
13.
Bioelectron Med ; 10(1): 1, 2024 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-38167312

RESUMEN

Regaining motor function in individuals with cerebral palsy (CP) has been predominantly studied in children, resulting in an underrepresentation of adults in research efforts. We tested the efficacy of noninvasive spinal neuromodulation with neurorehabilitation (Spinal Cord Innovation in Pediatrics; SCiP™ therapy). A 60-year-old CP participant underwent 8 weeks of SCiP™ therapy, resulting in significant motor recovery measured by 14.2-points increase in gross motor function measure (GMFM-88) score, ~ three times the Minimal Clinically Important Difference (MCID) of 5-points. This represented gains in kneeling, sitting, and walking functions. The improvement in GMFM-88 score was maintained above the MCID at the follow up visit (10.3 points above the baseline), twenty weeks following the last therapy session, indicating a persistent effect of the therapy. Our preliminary findings support the therapeutic promise of SCiP™ therapy for enhancing motor function in CP adults. Broader investigations are needed to establish its wider applicability.

14.
Exp Neurol ; 371: 114589, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-37907125

RESUMEN

Highly varying patterns of electrostimulation (Dynamic Stimulation, DS) delivered to the dorsal cord through an epidural array with 18 independent electrodes transiently facilitate corticospinal motor responses, even after spinal injury. To partly unravel how corticospinal input are affected by DS, we introduced a corticospinal platform that allows selective cortical stimulation during the multisite acquisition of cord dorsum potentials (CDPs) and the simultaneous supply of DS. Firstly, the epidural interface was validated by the acquisition of the classical multisite distribution of CDPs and their input-output profile elicited by pulses delivered to peripheral nerves. Apart from increased EMGs, DS selectively increased excitability of the spinal interneurons that first process corticospinal input, without changing the magnitude of commands descending from the motor cortex, suggesting a novel correlation between muscle recruitment and components of cortically-evoked CDPs. Finally, DS increases excitability of post-synaptic spinal interneurons at the stimulation site and their responsiveness to any residual supraspinal control, thus supporting the use of electrical neuromodulation whenever the motor output is jeopardized by a weak volitional input, due to a partial disconnection from supraspinal structures and/or neuronal brain dysfunctions.


Asunto(s)
Traumatismos de la Médula Espinal , Estimulación de la Médula Espinal , Humanos , Potenciales Evocados Motores/fisiología , Estimulación Eléctrica , Interneuronas , Médula Espinal , Tractos Piramidales/fisiología
15.
J Neural Eng ; 21(1)2024 02 07.
Artículo en Inglés | MEDLINE | ID: mdl-38271712

RESUMEN

Objective.Electrical spinal cord stimulation (SCS) has emerged as a promising therapy for recovery of motor and autonomic dysfunctions following spinal cord injury (SCI). Despite the rise in studies using SCS for SCI complications, there are no standard guidelines for reporting SCS parameters in research publications, making it challenging to compare, interpret or reproduce reported effects across experimental studies.Approach.To develop guidelines for minimum reporting standards for SCS parameters in pre-clinical and clinical SCI research, we gathered an international panel of expert clinicians and scientists. Using a Delphi approach, we developed guideline items and surveyed the panel on their level of agreement for each item.Main results.There was strong agreement on 26 of the 29 items identified for establishing minimum reporting standards for SCS studies. The guidelines encompass three major SCS categories: hardware, configuration and current parameters, and the intervention.Significance.Standardized reporting of stimulation parameters will ensure that SCS studies can be easily analyzed, replicated, and interpreted by the scientific community, thereby expanding the SCS knowledge base and fostering transparency in reporting.


Asunto(s)
Traumatismos de la Médula Espinal , Estimulación de la Médula Espinal , Humanos , Estimulación de la Médula Espinal/métodos , Médula Espinal
16.
J Neurophysiol ; 110(6): 1311-22, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23761695

RESUMEN

The rat spinal cord isolated from supraspinal control via a complete low- to midthoracic spinal cord transection produces locomotor-like patterns in the hindlimbs when facilitated pharmacologically and/or by epidural electrical stimulation. To evaluate the role of epidural electrical stimulation in enabling motor control (eEmc) for locomotion and posture, we recorded potentials evoked by epidural spinal cord stimulation in selected hindlimb muscles during stepping and standing in adult spinal rats. We hypothesized that the temporal details of the phase-dependent modulation of these evoked potentials in selected hindlimb muscles while performing a motor task in the unanesthetized state would be predictive of the potential of the spinal circuitries to generate stepping. To test this hypothesis, we characterized soleus and tibialis anterior (TA) muscle responses as middle response (MR; 4-6 ms) or late responses (LRs; >7 ms) during stepping with eEmc. We then compared these responses to the stepping parameters with and without a serotoninergic agonist (quipazine) or a glycinergic blocker (strychnine). Quipazine inhibited the MRs induced by eEmc during nonweight-bearing standing but facilitated locomotion and increased the amplitude and number of LRs induced by eEmc during stepping. Strychnine facilitated stepping and reorganized the LRs pattern in the soleus. The LRs in the TA remained relatively stable at varying loads and speeds during locomotion, whereas the LRs in the soleus were strongly modulated by both of these variables. These data suggest that LRs facilitated electrically and/or pharmacologically are not time-locked to the stimulation pulse but are highly correlated to the stepping patterns of spinal rats.


Asunto(s)
Potenciales Evocados Motores/efectos de los fármacos , Neurotransmisores/farmacología , Quipazina/farmacología , Médula Espinal/fisiología , Estricnina/farmacología , Caminata/fisiología , Anestesia Epidural , Animales , Estimulación Eléctrica , Femenino , Miembro Posterior/inervación , Miembro Posterior/fisiología , Músculo Esquelético/inervación , Músculo Esquelético/fisiología , Postura , Ratas , Ratas Sprague-Dawley
17.
J Neuroeng Rehabil ; 10: 2, 2013 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-23336733

RESUMEN

BACKGROUND: Stimulation of the spinal cord has been shown to have great potential for improving function after motor deficits caused by injury or pathological conditions. Using a wide range of animal models, many studies have shown that stimulation applied to the neural networks intrinsic to the spinal cord can result in a dramatic improvement of motor ability, even allowing an animal to step and stand after a complete spinal cord transection. Clinical use of this technology, however, has been slow to develop due to the invasive nature of the implantation procedures, the lack of versatility in conventional stimulation technology, and the difficulty of ascertaining specific sites of stimulation that would provide optimal amelioration of the motor deficits. Moreover, the development of tools available to control precise stimulation chronically via biocompatible electrodes has been limited. In this paper, we outline the development of this technology and its use in the spinal rat model, demonstrating the ability to identify and stimulate specific sites of the spinal cord to produce discrete motor behaviors in spinal rats using this array. METHODS: We have designed a chronically implantable, rapidly switchable, high-density platinum based multi-electrode array that can be used to stimulate at 1-100 Hz and 1-10 V in both monopolar and bipolar configurations to examine the electrophysiological and behavioral effects of spinal cord epidural stimulation in complete spinal cord transected rats. RESULTS: In this paper, we have demonstrated the effectiveness of using high-resolution stimulation parameters in the context of improving motor recovery after a spinal cord injury. We observed that rats whose hindlimbs were paralyzed can stand and step when specific sets of electrodes of the array are stimulated tonically (40 Hz). Distinct patterns of stepping and standing were produced by stimulation of different combinations of electrodes on the array located at specific spinal cord levels and by specific stimulation parameters, i.e., stimulation frequency and intensity, and cathode/anode orientation. The array also was used to assess functional connectivity between the cord dorsum to interneuronal circuits and specific motor pools via evoked potentials induced at 1 Hz stimulation in the absence of any anesthesia. CONCLUSIONS: Therefore the high density electrode array allows high spatial resolution and the ability to selectively activate different neural pathways within the lumbosacral region of the spinal cord to facilitate standing and stepping in adult spinal rats and provides the capability to evoke motor potentials and thus a means for assessing connectivity between sensory circuits and specific motor pools and muscles.


Asunto(s)
Terapia por Estimulación Eléctrica/instrumentación , Electrodos Implantados , Espacio Epidural/fisiología , Locomoción/fisiología , Traumatismos de la Médula Espinal/rehabilitación , Animales , Conducta Animal/fisiología , Interpretación Estadística de Datos , Impedancia Eléctrica , Electromiografía , Electrónica , Electrofisiología , Diseño de Equipo , Femenino , Cabeza , Miembro Posterior/fisiología , Músculo Esquelético/inervación , Músculo Esquelético/fisiología , Parálisis/fisiopatología , Parálisis/rehabilitación , Ratas , Ratas Sprague-Dawley , Traumatismos de la Médula Espinal/psicología
18.
J Neuroeng Rehabil ; 10: 108, 2013 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-24156340

RESUMEN

BACKGROUND: Epidural stimulation of the spinal cord can be used to enable stepping on a treadmill (electrical enabling motor control, eEmc) after a complete mid-thoracic spinal cord transection in adult rats. Herein we have studied the effects of eEmc using a sub-threshold intensity of stimulation combined with spontaneous load-bearing proprioception to facilitate hindlimb stepping and standing during daily cage activity in paralyzed rats. METHODS: We hypothesized that eEmc combined with spontaneous cage activity would greatly increase the frequency and level of activation of the locomotor circuits in paralyzed rats. Spontaneous cage activity was recorded using a specially designed swivel connector to record EMG signals and an IR based camcorder to record video. RESULTS AND CONCLUSION: The spinal rats initially were very lethargic in their cages showing little movement. Without eEmc, the rats remained rather inactive with the torso rarely being elevated from the cage floor. When the rats used their forelimbs to move, the hindlimbs were extended and dragged behind with little or no flexion. In contrast, with eEmc the rats were highly active and the hindlimbs showed robust alternating flexion and extension resulting in step-like movements during forelimb-facilitated locomotion and often would stand using the sides of the cages as support. The mean and summed integrated EMG levels in both a hindlimb flexor and extensor muscle were higher with than without eEmc. These data suggest that eEmc, in combination with the associated proprioceptive input, can modulate the spinal networks to significantly amplify the amount and robustness of spontaneous motor activity in paralyzed rats.


Asunto(s)
Actividad Motora/fisiología , Traumatismos de la Médula Espinal/fisiopatología , Estimulación de la Médula Espinal/métodos , Médula Espinal/fisiología , Animales , Modelos Animales de Enfermedad , Electrodos Implantados , Electromiografía , Femenino , Ratas , Ratas Sprague-Dawley
19.
Front Rehabil Sci ; 4: 1216281, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37565185

RESUMEN

Motor dysfunction in individuals with cerebral palsy (CP) such as the inability to initiate voluntary movements, walking with compensatory movement patterns, and debilitating spasticity is due to the aberrant neural connectivity between the brain and spinal cord. We tested the efficacy of noninvasive spinal cord neuromodulation (SCiP™, SpineX Inc.) with activity-based neurorehabilitation therapy (ABNT) in improving the sensorimotor function in six children with CP. Children received 8 weeks of either SCiP™ or sham therapy with ABNT (n = 3 per group). At the end of 8 weeks, all participants received 8 weeks of SCiP™ therapy with ABNT. Follow up assessments were done at week 26 (10 weeks after the last therapy session). Sensorimotor function was measured by the Gross Motor Function Measure 88 (GMFM88) test. We observed minimal change in sham group (mean 6% improvement), however, eight weeks of SCiP™ therapy with ABNT resulted in statistically and clinically relevant improvement in GMFM88 scores (mean 23% increase from baseline). We also observed reduced scores on the modified Ashworth scale only with SCiP™ therapy (-11% vs. +5.53% with sham). Similar improvements were observed in sham group but only after the cross over to SCiP™ therapy group at the end of the first eight weeks. Finally, sixteen weeks of SCiP™ therapy with ABNT resulted in further improvement of GMFM88 score. The improvement in GMFM88 scores were maintained at week 26 (10 weeks after the end of therapy), suggesting a sustained effect of SCiP™ therapy.

20.
Front Neurosci ; 17: 1221809, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37564370

RESUMEN

Introduction: Cerebral palsy (CP) affects up to 4 children in 1,000 live births, making it the most common motor disorder in children. It impairs the child's ability to move voluntarily and maintain balance and posture, and results in a wide range of other functional disorders during early development impairments in various sensory modalities, e.g., vision, hearing ability and proprioception. Current standard of care therapy focuses on symptom management and does not mitigate the progression of many of these underlying neurological impairments. The goal of this trial is to conduct a prospective multicenter, double-blinded, sham-controlled, crossover, randomized control trial to demonstrate the safety and efficacy of noninvasive spinal cord neuromodulation (SCiP™, SpineX Inc.) in conjunction with activity-based neurorehabilitation therapy (ABNT) to improve voluntary sensorimotor function in children with cerebral palsy. Methods and analysis: Sixty participants (aged 2-13 years) diagnosed with CP classified as Gross Motor Function Classification Scale Levels I-V will be recruited and divided equally into two groups (G1 and G2). Both groups will receive identical ABNT 2 days/wk. G1 will initially receive sham stimulation, whereas G2 will receive therapeutic SCiP™ therapy for 8 weeks. After 8 weeks, G1 will cross over and receive therapeutic SCiP™ therapy for 8 weeks, whereas G2 will continue to receive SCiP™ therapy for another 8 weeks, for a total of 16 weeks. Primary and secondary outcome measures will include Gross Motor Function Measure-88 and Modified Ashworth Scale, respectively. Frequency and severity of adverse events will be established by safety analyses. Ethics and dissemination: The trial is registered on clinicaltrials.gov (NCT05720208). The results from this trial will be reported on clinicaltrials.gov, published in peer-reviewed journals and presented at scientific and clinical conferences.

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