RESUMEN
Neural networks in the spinal cord can generate the walking pattern and control posture in the absence of supraspinal influences. A technology using transcutaneous electrical spinal cord stimulation (tSCS) was created. During walking, tSCS activated spinal locomotor networks, as well as leg flexor/extensor motor pools in the swing/stance phases, respectively. It was assumed that the use of this technology in subjects with locomotion disorders would improve walking. Patients with hemiparesis were studied 3-11 months after stroke, the duration of the course was 2 weeks. Patients of the main and control groups received standard therapy and rehabilitation using the technology; in the control group, sham tSCS was used. After the course, minimal clinically important differences in walking parameters were achieved in the main group, in contrast to the control group. The developed technology is an effective means of restoring walking in patients with hemiparesis.
Asunto(s)
Accidente Cerebrovascular , Estimulación Eléctrica Transcutánea del Nervio , Humanos , Locomoción/fisiología , Caminata/fisiología , Médula Espinal/fisiología , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/terapiaRESUMEN
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..
Asunto(s)
Potenciales Evocados Motores , Extremidades/fisiopatología , Traumatismos de la Médula Espinal/fisiopatología , Estimulación de la Médula Espinal/métodos , Estimulación Eléctrica Transcutánea del Nervio/métodos , Adulto , Extremidades/inervación , Femenino , Humanos , Región Lumbosacra/fisiopatología , Masculino , Contracción Muscular , Traumatismos de la Médula Espinal/terapia , Nervio Cubital/fisiopatologíaRESUMEN
Is it possible to regulate the functional properties of abnormally developed spinal neuronal locomotor networks using transcutaneous spinal cord stimulation? This question has been studied in twenty-eight participants (â¼9 yrs) with spastic cerebral palsy, and mainly Gross Motor Function Classification System for Cerebral Palsy level III. The participants were randomly assigned to two groups. The experimental group received transcutaneous spinal cord stimulation at two spinal levels (over T11 and L1 spinous processes), combined with locomotor treadmill training, whereas the participants of the control group received locomotor treadmill training only. After spinal cord stimulation in the experimental group we found an incremental increase in knee torque whereas in the control group this effect was absent. The amplitude of hip motion increased in both groups. A decrease of co-activation of hip and muscles of the lower extremities was observed in the experimental group while in the control group co-activation decreased only in hip muscles. The results support the idea that locomotor function can be improved significantly with the combination of training and transcutaneous spinal cord stimulation than with training alone.
Asunto(s)
Parálisis Cerebral/terapia , Estimulación de la Médula Espinal , Médula Espinal/fisiopatología , Caminata/fisiología , Parálisis Cerebral/fisiopatología , Niño , Prueba de Esfuerzo/métodos , Humanos , Modalidades de Fisioterapia , Traumatismos de la Médula Espinal/fisiopatología , Traumatismos de la Médula Espinal/terapia , Estimulación de la Médula Espinal/métodos , Estimulación Eléctrica Transcutánea del Nervio/métodosRESUMEN
Multisegmental muscle responses (MMR) are reflexes in the leg muscles evoked by transcutaneous electrical spinal cord stimulation over the Th11Th12 vertebrae. We have used MMR to evaluate the excitability of lumbosacral motor neurons in individuals suffering lower paraplegia. Ten individuals were tested using H-reflexes and MMR bilaterally before (n 0 = 20) and during 4-weeks course of rehabilitation (n=76). The H-reflex and MMR of m. gastrocnemius lateralis were obtained in: 15 and 13 cases out of 20, respectively. Both reflexes were recorded in 11 and were absent in 3 cases, matched up to 70% of recordings. In dynamic, the both methods were 100% reproducible and the responses' amplitude varied in similar directions in 67% of records. The data confirm the validity and reproducibility of the MMR for evaluation of the motor neurons excitability in lumbosacral cord. The H-reflex magnitude shows moderate correlation with MMR in m. gastrocnemius lateralis (r = 0.59, p < 0.001), and low correlation with MMR in mm. rectus femoris, biceps femoris, and tibialis anterior (r < 0.40, p < 0.001). These findings do not allow extrapolate the results from the H-reflex measurement on the state of lumbosacral cord. At the same time, measurements of the MMR allow estimate simultaneously the excitability of motor pools innervating several muscle groups. This makes advantageous to assess the functional state of the motor neurons in the lumbosacral spinal cord for clinical and experimental studies, including the spinal cord damage.
Asunto(s)
Región Lumbosacra/fisiopatología , Neuronas Motoras/fisiología , Traumatismos de la Médula Espinal/fisiopatología , Estimulación de la Médula Espinal/métodos , Médula Espinal/fisiopatología , Estimulación Eléctrica Transcutánea del Nervio/métodos , Adulto , Reflejo H , Humanos , Masculino , Persona de Mediana Edad , Músculo Esquelético/inervación , Paraplejía/fisiopatología , Paraplejía/rehabilitación , Traumatismos de la Médula Espinal/rehabilitación , Adulto JovenRESUMEN
Recently transcutateous electrical spinal cord stimulation began to be used both for experimental studies of motor functions regulation and for rehabilitation of motor functions in patients with spinal cord injury. The spinal cord is a very important center of vital functions regulation and the spinal cord stimulation directed to the activation of spinal locomotor related networks will affect visceral systems as well. This circumstance is necessary to take into account when this new method will be used for rehabilitation as well as for the studies on healthy subjects. Here the review of publications related to effects of electrical spinal cord stimulation on peripheral and cerebral circulation, on the cardiovascular, respiratory, excretory, and digestive systems of mammals is presented.
Asunto(s)
Circulación Sanguínea , Estimulación de la Médula Espinal , Animales , Fenómenos Fisiológicos Cardiovasculares , Fenómenos Fisiológicos del Sistema Digestivo , HumanosRESUMEN
In the present study, the mechanisms of interaction between the breathing and stepping movements were investigated. The investigations were carried out in 8 normal subjects and 4 individuals with complete spinal cord lesion. Additionally, experimental studies were performed in 7 decerebrate and 4 spinal cats. Involuntary reflex stepping movements in the air were induced by vibrators attached above a tendon of m. rectus femoris and m. biceps femoris. In the spinal patients, epidural stimulation was carried out with electrodes located in the posterior epidural space at the vertebral level Th11. It was found that voluntary-induced stepping, which are accompanied by visceral reactions, were mediated by the central mechanisms. Changes in breathing pattern in response to vibration-induced involuntary stepping movements point up to the peripheral component being predominant in such interactions. In the spinal patients under epidural spinal cord stimulation delivered below the site of injury, the reaction in the cardio-respiratory system was abolished. Vibrations to the leg muscles also did not evoke respiratory responses. However, in the condition of forced breathing such vibrations evoked the rhythmic bursting EMG activity in m. rectus femoris, which was in harmony with the breathing rhythm. The results confirmed the presence of an interaction between breathing and stepping generators. This interaction is underlain both by central and peripheral components.
Asunto(s)
Locomoción/fisiología , Músculo Esquelético/fisiología , Mecánica Respiratoria/fisiología , Enfermedades de la Médula Espinal/fisiopatología , Animales , Gatos , Estado de Descerebración , Electrodos Implantados , Electromiografía , Humanos , Músculo Esquelético/fisiopatología , Reflejo/fisiología , CaminataRESUMEN
A method for functional evaluation of spinal cord conducting systems in patients with vertebrospinal diseases is proposed. The method is based on the analysis of changes in electrospinoneurogram recorded with epidural electrodes below the injury during an attempt at voluntary activation of foot muscles. The degree of changes in electrospinoneurogram frequency during voluntary command addressed to motoneurons of the lumbar enlargement reflect the state of descending spinal systems.