Restoring Control Following Spinal Cord Injury
Three spinal-cord injured patients have recovered some ability to walk following treatments at the Mayo Clinic in Minnesota and the Kentucky Spinal Cord Injury Research Center in Louisville. All used the same therapeutic proceedure, which involved implanting an electrical stimulator near the spine below the injury to supplement signals from the few surviving spinal cord connections. Therapists fine-tuned the stimulation by trial and error as they moved the suspended patients' legs in a walking pattern. As the patients gained control themselves they progressed to front-wheeled walkers. One patient was able to walk 102 meters and another 362 meters. Two additional patients were able to stand but not walk, possibly because of a lack of adequate surviving connections. Nature Medicine, DOI: 10.1038/s41591-018-0175-7; New England Journal of Medicine, Vol 379, 1244-1250.
    Another technique involves bypassing the spinal cord completely. A microchip implanted in the brain detects neural activity at 96 points in the motor cortex and sends signals to a decoder, which in turn sends processed signals to electrodes on the surface of the arm. When Ian Burkhart suffered a C5 level spinal cord break in a diving accident he lost the ability to control his lower body as well as his arms below the elbow; with this device he can now grasp objects and manipulate them with his hand. The next step is to make the equipment portable so he can use it at home. Nature Medicine, DOI: 10.1038/s41591-018-0171-y. You can read more about the device and see a video demonstration of the patient using it here.

The Stochastic Entanglement Hypothesis of Phantom Pain
One of the hypotheses offered to explain phantom limb pain is that it is due to the intrusion of neurons from other brain areas into the unused somatosensory area that once served the missing limb. Max Ortiz-Catalan puts a new twist on that idea in his stochastic entanglement hypothesis. According to him, phantom pain occurs when the random firing of unused neurons in the missing limb's somatosensory area coincides with firing of pain fibers, causing the two groups of neurons to form connections with each other. Formation of these new connections represents a time-honored principle attributed to Donald Hebb that "neurons that fire together wire together." According to Ortiz-Catalan, his treatment in which an amputee sees himself on a screen with the amputated limb replaced by a virtual one the patient can move improves phantom pain by weakening those entangled connections. Frontiers in Neurology, DOI: 10.3389/fneur.2018.00748

Brief Weightlessness Alters Body Consciousness and the Default Mode Network
We orient ourselves in space by integrating sensory information about the body and the environment in the right temporo-parietal junction (rTPJ). Weightlessness experienced in space results in spatial disorientation early in flight and again on the return to earth. The ability to produce weightlessness during parabolic flights, in which an airplane repeatedly descends rapidly from higher altitudes, provided the opportunity for researchers to study how this experience affects the brain. Volunteers underwent MRI scans before and after flight. Even though total time of weightlessness amounted to only 10 minutes, activity in the rTPJ was reduced following the flight, presumably as a reaction to conflicting inputs. In addition, reduced connectivity occurred in the default mode network, which is important for cognitive processing and level of consciousness. Nature Scientific Reports, DOI:10.1038/s41598-017-03170-5.

Adding Kinesthesis to Prosthetic Hands
Prosthetic hands are now remarkably well developed, allowing amputees to function reasonably normally, but with one major drawback: Lacking kinesthetic feedback, the user has to monitor the prosthesis visually in order to know where the hand is in space, whether all the fingers are gripping in coordination, and so on. Six amputees have now been fitted with prostheses that send feedback to the upper arm in the form of subtle vibrations. Three of the individuals learned to use this feedback within minutes; they were more accurate in correcting errors and they felt more in control of their prostheses. Science Translational Medicine, DOI: 10.1126/scitranslmed.aao6990.