Sense of touch is essential for hand use, but people with spinal cord injury can lose this basic function.
Now researchers from University of Pittsburgh and University of Chicago use a brain stimulation technique to help paralyzed patients recover their sense of touch. The finding is newly published in Science Translational Medicine.
In the study, researchers implanted microelectrode arrays into the primary somatosensory cortex of a 28-year old patient with spinal cord injury. Primary somatosensory cortex is the main sensory receptive area for the sense of touch.
Researchers delivered current through the electrodes, which generated sensations of touch that were perceived as coming from the patient’s own paralyzed hand.
To the patient, the sensations were felt like pressure, had different intensity, and were stable for months.
Furthermore, researchers could modulate the current amplitude to generate the pressure necessary for holding objects.
Researchers suggest that it is important the microstimulation of sensory cortex can elicit natural sensation rather than tingling. Moreover, the stimulation is safe, and the evoked sensations can last over months.
Nevertheless, more work is needed to create stimulation patterns to help patients make better movements. Achieving such a goal will be much more complex than simply moving hand muscles.
We can differentiate between objects through touch and grasping, and the constant feedback we receive from the sense of touch is very important as it tells the brain where to move and by how much.
In the next step of the study, researchers will look for the right candidate, develop their brain stimulation system, and refine the stimulation procedure. The ultimate goal is to create a system which moves and feels just like a natural arm would.
Citation: Flesher SN, et al. (2016) Intracortical microstimulation of human somatosensory cortex. Science Translational Medicine, published online. DOI:10.1126/scitranslmed.aaf8083.
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