An experimental treatment may have “started” the brains of two patients who had been in a minimally conscious state for months after a coma, according to a new study.
Both patients had severe brain injuries and had shown only limited signs of consciousness for more than a year. But after receiving the treatment – which involved ultrasound to “excite” cells in a region of the brain called the thalamus – patients experienced a sudden improvement in their condition, according to the study, published Jan. 15 in the newspaper. Cerebral stimulation. For example, after treatment, a patient may move his head to indicate “yes” or “no” in response to certain questions.
This rapid recovery is uncommon in patients in a prolonged state of minimal consciousness – meaning that the person is awake, but shows only small signs of consciousness. In these patients, “any recovery usually occurs slowly over several months and more typically years,” study co-author Martin Monti, professor of psychology and neurosurgery at the University of California, Los Angeles, said in a statement. But these two patients showed significant progress in just a few days to weeks, he said.
Previous studies have found that stimulating the thalamus with surgically implanted electrodes can lead to similar improvements, but this method is invasive and does not work on all patients, said Dr. Neel Singhal, assistant professor of neurology at the University of California, San Francisco who did not participated in the study. Singhal called the new research “innovative” because the method is “non-invasive and can potentially be applied to a much broader group of patients than deep brain stimulation”.
However, the new findings are very preliminary and the ultrasound method does not appear to help all patients. There were a total of three patients in the new study; of the two patients who benefited, one showed an initial improvement, but later regressed, and a third patient showed no benefit.
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Sudden improvement
For the study, doctors used a disk-like device to target ultrasonic pulses in specific areas of the brain. In this case, the researchers targeted the thalamus, a structure deep in the brain that acts as a center for transmitting sensory information to other parts of the brain. They targeted this region because their performance is typically weakened after a coma, the researchers said.
The three patients in the study underwent two 10-minute sessions with the device, one week apart.
One of the patients was a 56-year-old man who was in a minimally conscious state for 14 months after having a leakage. After the ultrasound treatment, the man showed that he was able to consistently respond to commands such as dropping a ball or looking at pictures of his relatives when he heard their names. He can also nod “yes” and shake his head to say “no” when asked about himself. And for the first time since the stroke, he could use a pen and paper and put a bottle in his mouth. However, the man regressed to his minimally conscious state after a few months.
The second patient was a 50-year-old woman who was in a minimally conscious state for 2.5 years after cardiac arrest. She had shown no previous response when receiving any commands, but after treatment, she consistently responded to commands by moving her head or fingers. She was also able to recognize objects, including a pencil and a comb, for the first time in years. The woman maintained her improvements during the six-month follow-up period, they said.
The third patient, a 58-year-old man who had been in a state of minimal consciousness for 5.5 years after a car accident, showed no benefit from the treatment.
Innovative discoveries
In 2016, that same group of researchers used ultrasound treatment on a 25-year-old man who had been in a minimally conscious state for just a few weeks. In that case, the treatment also seemed to light up his brain – he soon recovered fully consciousness and understanding of language.
But at that time, the researchers warned that the discovery may have been just a coincidence – in other words, the man may have recovered spontaneously as soon as the researchers started treatment. In the new report, it is “very unlikely” that the two patients recovered spontaneously, given the time they were in a minimally conscious state, Monti said.
As to why the third patient in the new study did not respond to treatment, the researchers speculate that the person’s thalamus may have been damaged or disconnected from other regions of the brain. In this subset of patients, this method may not help.
“Just to give you an example, if someone had a ‘totally disconnected’ thalamus, we could stimulate it as much as we want, and it would not help to rekindle the complex web of brain networks needed for complex cognitive functions (and behavior),” Monti said Live Science by email.
Although the changes observed in the study are small, they can mean a lot to patients and their families. “For our patients, even if they are only able to communicate with their loved ones – in a restricted way … it can mean recovering the ability to be part of their social environment, the life of their loved ones, and recovering some degree of autonomy personal, “said Monti.
The researchers said they are investigating whether the dose and frequency of exposure to ultrasound can affect the level and duration of the benefit. “With fine-tuning the stimulation protocol, patient selection and device, this can have tangible benefits for patients with severe brain injuries,” who currently do not have definitely effective treatments available to improve neurological recovery, Singhal told Live Science.
The authors emphasized that ultrasound treatment is experimental and probably will not be available to the public for several years.
Originally published on Live Science.