A man who spent the last 15 years in a vegetative state is showing signs of consciousness after doctors used a new technique to stimulate his brain.
The 35-year-old patient was involved in a car accident in 2001 and was unresponsive ever since.
Dr Angela Sirigu and her team at the French National Centre for Scientific Research published their study in medical journal, Current Biology, and detailed a new technique they had been researching.
Sirigu told CNN that they decided to run the test on this specific patient because, after regular examinations, had displayed no improvement in 15 years. He wasn’t someone who had been in a vegetative state for a short period of time, and whose health could have improve spontaneously.
Using vagus nerve stimulation (VNS), the team of doctors and scientists connected tiny electrodes to the vagus nerve, located in his neck and began to stimulate it, starting with a low electrical current of 0.25 milliamps.
The impulses would then travel along the nerve to the brain stem where they would transmit to various parts of the brain.
The team treated the patient for six months, each time stimulating the nerve for 30 seconds, then allowing the patient to rest for five minutes. Each week, the electrical current was increased by 0.25 milliamps until it reached 1.5 milliamps.
Connection to many organs
The vagus nerve is said to be the longest cranial nerve in the human body. It is number 10 of the 12 cranial nerves and connects with several organs – from the brain, it connects with the oesophagus (the throat), the heart, the lungs, and the gut.
The word “vagus” is Latin, which translated to English means “wandering”. While the nerve connects to many organs in the body, it is also connected to a few sections of the brain:
- The hypothalamus, which regulates hunger and thirst, body temperature, fatigue and sleep, along with important aspects of parenting.
- The thalamus, which processes and relays sensory information to another part of the brain, regulating consciousness, alertness and sleep.
- The hippocampus, which takes responsibility for your memories – short-term, long-term and navigational memory. It’s also responsible for approach-avoidance conflicts, which is when a situation has both positive and negative effects. It is speculated that the vagus nerve is also responsible for that “gut feeling” when feeling uncertain or having a hunch about something (hyperlink psychology today article).
Before the team began the VNS treatment, they ran many tests and captured data so that once they started treatment, they could see how far they had come.
Once treatment had begun, Sirigu and her team noticed changes in the patient’s behaviour. He was opening his eyes much more than previously, and after a few weeks into the treatment, he began looking at people and following them with his gaze as they moved through the room; he also started moving his head. The team is yet to ask him to answer yes or no questions with a nod or shake of his head.
A viable new treatment
Professor Steven Laureys, head of the Coma Science Group at the University of Liege’s Department of Neurology told New Scientist that he’s happy to see results, because many physicians regard patients in a vegetative state as simply waiting to die.
He said he disagrees and thinks there should always be hope, and instead lauded the team for making use of VNS, saying it may be a viable new treatment.
Sirigu said that the chances of this patient being fully functional again – walking and talking – is basically impossible due to the extent of the damage to his brain. The team however remain hopeful that their discovery could be used to treat other patients in a vegetative state, and will continue using this method of treatment to determine whether comparable results can be achieved.