RESUMEN
A spinal cord injury interrupts the communication between the brain and the region of the spinal cord that produces walking, leading to paralysis1,2. Here, we restored this communication with a digital bridge between the brain and spinal cord that enabled an individual with chronic tetraplegia to stand and walk naturally in community settings. This brain-spine interface (BSI) consists of fully implanted recording and stimulation systems that establish a direct link between cortical signals3 and the analogue modulation of epidural electrical stimulation targeting the spinal cord regions involved in the production of walking4-6. A highly reliable BSI is calibrated within a few minutes. This reliability has remained stable over one year, including during independent use at home. The participant reports that the BSI enables natural control over the movements of his legs to stand, walk, climb stairs and even traverse complex terrains. Moreover, neurorehabilitation supported by the BSI improved neurological recovery. The participant regained the ability to walk with crutches overground even when the BSI was switched off. This digital bridge establishes a framework to restore natural control of movement after paralysis.
Asunto(s)
Interfaces Cerebro-Computador , Encéfalo , Terapia por Estimulación Eléctrica , Rehabilitación Neurológica , Traumatismos de la Médula Espinal , Médula Espinal , Caminata , Humanos , Encéfalo/fisiología , Terapia por Estimulación Eléctrica/instrumentación , Terapia por Estimulación Eléctrica/métodos , Cuadriplejía/etiología , Cuadriplejía/rehabilitación , Cuadriplejía/terapia , Reproducibilidad de los Resultados , Médula Espinal/fisiología , Traumatismos de la Médula Espinal/complicaciones , Traumatismos de la Médula Espinal/rehabilitación , Traumatismos de la Médula Espinal/terapia , Caminata/fisiología , Pierna/fisiología , Rehabilitación Neurológica/instrumentación , Rehabilitación Neurológica/métodos , MasculinoRESUMEN
Spinal cord injury leads to severe locomotor deficits or even complete leg paralysis. Here we introduce targeted spinal cord stimulation neurotechnologies that enabled voluntary control of walking in individuals who had sustained a spinal cord injury more than four years ago and presented with permanent motor deficits or complete paralysis despite extensive rehabilitation. Using an implanted pulse generator with real-time triggering capabilities, we delivered trains of spatially selective stimulation to the lumbosacral spinal cord with timing that coincided with the intended movement. Within one week, this spatiotemporal stimulation had re-established adaptive control of paralysed muscles during overground walking. Locomotor performance improved during rehabilitation. After a few months, participants regained voluntary control over previously paralysed muscles without stimulation and could walk or cycle in ecological settings during spatiotemporal stimulation. These results establish a technological framework for improving neurological recovery and supporting the activities of daily living after spinal cord injury.
Asunto(s)
Tecnología Biomédica , Terapia por Estimulación Eléctrica , Parálisis/rehabilitación , Traumatismos de la Médula Espinal/rehabilitación , Caminata/fisiología , Actividades Cotidianas , Simulación por Computador , Electromiografía , Espacio Epidural , Humanos , Pierna/inervación , Pierna/fisiología , Pierna/fisiopatología , Locomoción/fisiología , Masculino , Neuronas Motoras/fisiología , Músculo Esquelético/inervación , Músculo Esquelético/fisiología , Músculo Esquelético/fisiopatología , Parálisis/fisiopatología , Parálisis/cirugía , Médula Espinal/citología , Médula Espinal/fisiología , Médula Espinal/fisiopatología , Traumatismos de la Médula Espinal/fisiopatología , Traumatismos de la Médula Espinal/cirugíaRESUMEN
People with late-stage Parkinson's disease (PD) often suffer from debilitating locomotor deficits that are resistant to currently available therapies. To alleviate these deficits, we developed a neuroprosthesis operating in closed loop that targets the dorsal root entry zones innervating lumbosacral segments to reproduce the natural spatiotemporal activation of the lumbosacral spinal cord during walking. We first developed this neuroprosthesis in a non-human primate model that replicates locomotor deficits due to PD. This neuroprosthesis not only alleviated locomotor deficits but also restored skilled walking in this model. We then implanted the neuroprosthesis in a 62-year-old male with a 30-year history of PD who presented with severe gait impairments and frequent falls that were medically refractory to currently available therapies. We found that the neuroprosthesis interacted synergistically with deep brain stimulation of the subthalamic nucleus and dopaminergic replacement therapies to alleviate asymmetry and promote longer steps, improve balance and reduce freezing of gait. This neuroprosthesis opens new perspectives to reduce the severity of locomotor deficits in people with PD.
Asunto(s)
Estimulación Encefálica Profunda , Trastornos Neurológicos de la Marcha , Enfermedad de Parkinson , Masculino , Animales , Humanos , Enfermedad de Parkinson/complicaciones , Enfermedad de Parkinson/terapia , Trastornos Neurológicos de la Marcha/etiología , Trastornos Neurológicos de la Marcha/terapia , Marcha/fisiología , Médula EspinalRESUMEN
Epidural electrical stimulation (EES) targeting the dorsal roots of lumbosacral segments restores walking in people with spinal cord injury (SCI). However, EES is delivered with multielectrode paddle leads that were originally designed to target the dorsal column of the spinal cord. Here, we hypothesized that an arrangement of electrodes targeting the ensemble of dorsal roots involved in leg and trunk movements would result in superior efficacy, restoring more diverse motor activities after the most severe SCI. To test this hypothesis, we established a computational framework that informed the optimal arrangement of electrodes on a new paddle lead and guided its neurosurgical positioning. We also developed software supporting the rapid configuration of activity-specific stimulation programs that reproduced the natural activation of motor neurons underlying each activity. We tested these neurotechnologies in three individuals with complete sensorimotor paralysis as part of an ongoing clinical trial ( www.clinicaltrials.gov identifier NCT02936453). Within a single day, activity-specific stimulation programs enabled these three individuals to stand, walk, cycle, swim and control trunk movements. Neurorehabilitation mediated sufficient improvement to restore these activities in community settings, opening a realistic path to support everyday mobility with EES in people with SCI.