Researchers found adaptive plastic changes in an amputee’s brain following implantation of multielectrode arrays inside peripheral nerves, according to a recent study published in Restorative Neurology and Neuroscience.
Researchers implanted four microelectrode arrays in the ulnar and median nerves of the stump of a 26-year-old man with a transradial left arm amputation. Prior to implantation, he was trained for 2 weeks by video to perform three specific movements with his phantom hand and then used the same hand grip tasks to control a hand prosthesis using the implanted microelectrodes. Researchers delivered electrical pulses to the nerves activated by each movement, providing the patient with sensory feedback. Electroencephalographic data was recorded and analyzed as the patient moved his right hand and the prosthesis.
Prior to implantation, commands to move the phantom left hand triggered the primary sensory and motor areas on the left side of the brain, as well as the pre-motor and supplementary motor cortices on both sides of the brain. After 4 weeks of prosthesis motor control training with implanted microelectrodes, cerebral activation changes were noted. New signals were delivered through peripheral nerves toward the cortex via the intra-fascicular electrodes, producing an intensive exchange of sensori-motor afferent and efferent inputs and outputs. Cortical recruitment became almost symmetrical with right hand movements, and new functional recruitment of sensorimotor areas devoted to hand control were evident.
“We found that a neutrally-interfaced hand prosthesis re-established communication between the central and peripheral nervous systems, not only restructuring the areas directly responsible for motor control but also their functional balance within the bi-hemispheric system necessary for motor control,” Camillo Porcaro, PhD, of the Institute of Neuroscience, Newcastle University Medical School, Newcastle upon Tyne, UK, stated in a press release. “Taken together, the results of this study confirm that neural interfaces are optimal candidates for hand prosthesis control. They establish communication channels needed for natural control of the prosthesis. Furthermore, neural interfaces recreate the connection with the environment that promotes restorative neuroplasticity. Bi-hemispheric networks regain the physiological communication necessary for motor control.”
For more information:
Di Pino G, Porcaro C, Tombini M, et al. A neurally-interfaced hand prosthesis tuned inter-hemispheric communication. Restor Neurol Neurosci. Aug. 21, 2012. [Epub ahead of print]
Disclosure: Porcaro has no relevant financial disclosures.
