A wireless brain-spine interface alleviating gait deficits after Parkinson’s disease in primates

“Levodopa and deep brain stimulation alleviate most of the symptoms associated with Parkinson*s disease. However, axial gait disorders are less responsive to these treatments. These deficits include short and slow steps, balance deficits and freezing of gait that involves episodes during which the affected persons are not capable of initiating locomotion.
Over the past decade, we have established a mechanistic and technological framework that guided the design of electrical spinal cord stimulation protocols engaging extensor and flexor muscle groups. We created an interface between the leg motor cortex activity and these spatially selective stimulation protocols, so as to engineer a brain*spine interface * a neuroprosthetic system that reinforced intended movements. As early as 6 days after spinal cord injury, this brain*spine interface restored weight-bearing locomotor movements of the paralyzed leg in nonhuman primates. Here, we show that the brain- spine interface effectively alleviates axial gait deficits observed in Parkinson*s disease. These experiments were conducted in MPTP-treated Rhesus macaque monkeys, which is the gold model to reproduce Parkinson*s disease symptomatology. After MPTP treatment, a rhesus macaque was implanted with the wireless brain-spine interface. Brain recordings of the left and right leg motor cortex were used to detect neural states related to flexion and extension movements of both legs while the animal walked freely overground or over a horizontal ladder. The detection of these gait events controlled an implanted pulse generator that delivered electrical stimulation through two e-dura electrode array implants that covered the dorsal aspects of the lumbar and sacral spinal cord.”