Scientists from UCLA have achieved a remarkable world first by using ultrasound to reactivate the brain of a man who had been left with limited consciousness following a period in a coma. "It's almost as if we were jump-starting the neurons back into function,” explained lead researcher Martin Monti in a statement.

Many people never fully regain their cognitive capacities after being in a coma, and are often left in a vegetative or minimally conscious state for the rest of their lives. Most attempts to restore patients to full brain function tend to focus on activating a brain region called the thalamus, which is sometimes likened to a consciousness switch.

However, at present, there are only two techniques for doing so, both of which have major drawbacks. The first of these is called deep brain stimulation, and involves implanting electrodes into a patient’s brain, which is highly invasive and can sometimes be dangerous. The second, called transcranial direct current stimulation, is non-invasive as it uses electrodes placed on the outside of the head to stimulate certain parts of the brain’s outer cortex, but isn’t strong enough to directly activate deeper regions like the thalamus.

Reporting their work in the journal Brain Stimulation, the researchers describe the case of a 25-year-old man who exhibited minimal signs of being conscious. Pioneering a technique called low intensity focused ultrasound pulsation (LIFUP), the team fired blasts of acoustic energy with a frequency of 100 Hertz at the patient’s thalamus. Using a small device placed close to the man’s head, they delivered a total of 10 pulses, each lasting 30 seconds and separated by 30-second intervals.

^{Acoustic energy was directed at a brain region called the thalamus. Martin Monti/UCLA}

The following day, the patient displayed considerable improvements in his ability to move and talk, and by the third day after treatment he had recovered his full ability to comprehend language and respond to questions by nodding or shaking his head. He was even able to give one of the doctors a fist bump, and on day five made his first attempt to walk.

Because this is the first time that LIFUP has been trialed on a human subject, the study authors are not getting carried away just yet, and say they need to replicate these results on other people before heralding it as a total success. If this can be achieved, however, they hope to see LIFUP become a regular treatment for people in vegetative or minimally conscious states.