Minimally conscious people woken with brain zap by their family

[Lance]

From New Scientist  Magazine May 26 2018

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PEOPLE in a minimally conscious state have been "woken" at home for the first time, using brain stimulation therapy delivered by their family.

Some of those in the trial could respond to questions from their loved ones, having been unresponsive for years.

"They were more present... laughing when someone was telling a joke or crying when they heard sad news," said one family member. "It was nice to see them laugh at funny scenes on the TV."

People with severe brain trauma often fall into a coma. This can improve to a state of minimal consciousness, where they might show fluctuating signs of awareness but remain unable to communicate.

In 2014, Steven Laureys at Liège University Hospital in Belgium and his colleagues discovered that people in a minimally conscious state could be temporarily roused using mild electrical stimulation.

The people in his trial were able to respond to commands and answer questions for a few hours before drifting back into an uncommunicative state.

Last year, Laureys and his team showed they could extend the period of awakening to a week by applying the stimulation over five consecutive days.

Now, they have taken the therapy out of the lab and into the patient's own home by teaching their family members or carers to use the stimulation device.

The study involved 27 people, one of whom had been in a minimally conscious state for 33 years (Brain Stimulation, doi.org/cp3j). Each received a 20-minute session of stimulation every weekday for four weeks, or a sham treatment. Eight weeks later, they received the other therapy. No one directly involved was aware of the treatment order.

When the team tested the participants one to two days after the real treatment had finished, a fifth showed improvements in awareness that were not observed at the end of the placebo sessions. A few people regained the ability to answer questions, such as "Am I touching my nose?".

To communicate, each patient was taught a code based on how responsive they were, including thumbs up or down, or even just blinking to signify yes or no.

All those in the trial were in a chronic minimally conscious state, meaning they had shown no improvement for several years. "We'd expect even better results for people with more recent brain injuries," says co-author Géraldine Martens, also at Liège University Hospital.

The study involved a technique called transcranial direct current stimulation (tDCS), which uses a tiny amount of electricity to make neurons more or less likely to fire. The stimulation device is placed over the prefrontal cortex, a brain region involved in higher cognitive functions such as consciousness and decision-making. This area is also linked to neural "hubs" that help direct information around the brain.

In conscious people, electrical activity spreads around the brain like a wave. Increasing the activity in the prefrontal cortex using tDCS is thought to partly recreate this wave of communication.

The device was configured to apply 2 milliamps of stimulation. "We think that a longer protocol with higher current might have better or more long-lasting results," says Martens, "but these people can't communicate pain so we have to be really careful about possible side effects."

The team acknowledges that it can be difficult for families to see improvements in such a trial, only for their relative to return to their previous state. In light of this, an ethics board allowed the families to keep the device after the trial. They have been told not to use it more than once a day, and never at weekends. "They've had it for about a month, so we'll be catching up with them soon to see what has happened," says Martens.

"This is a great step forward," says Joseph Fins, chief of the medical ethics division at Weill Cornell Medicine, New York. But how therapeutically meaningful it is still has to be assessed, he says. Fins and his colleagues previously used deep brain stimulation to temporarily awaken a man who had been in a minimally conscious state for six years, after which he was able to form short sentences and interact with his family.

After stimulation ends, the individual does gradually return to their pre-treatment state, says John Whyte, director of the Moss Rehabilitation Research Institute in Pennsylvania. "However, there is reason to hope that the therapy could be continued indefinitely to maintain the improved performance."

This article appeared in print under the headline "Woken up with a brain zap"

Helen Thomson

Edited May 27, 2018 by Lance