After 15 years in a vegetative state, patient has consciousness restored by doctors through a new method of nerve stimulation. 

Many people use the word ‘coma’ very generally for a wide variety of conditions affecting conscious parts of the brain. Here’s a short explanation on the difference between a coma and a vegetative state. Comas usually only last a few weeks at most. It is effectively the brain, ‘shutting down’ in response to extreme trauma. A patient in a coma is completely unresponsive. They do not move, react to light, sound or pain. As mentioned before this only usually lasts a few weeks. If the brain injury is serious enough then move into a vegetative state.

A patient that is in a vegetative state is still unconscious. They still have no conscious awareness of anything going on around them. However, the body may seem awake while this is happening. The patient’s eyes might be open giving the effect that they’re awake. They will move parts of their body but these actions are not conscious. These movements include thrashing, grinding teeth and making facial expressions. The patient will also have reflex responses such as jerks of the body in response to pain, bright lights or sound. It is also possible that they may produce sounds such as grunting and even occasional words. 

After four weeks it is considered a prolonged vegetative state. If they remain in a vegetative state for one year then it is considered a permanent vegetative state and the chances of recovery are very low.

But 15 years after the patient fell into a “permanent” vegetative state, doctors used a medical implant to stimulate the vagus nerve. This nerve is one of the most important nerves as it links the head to the rest of the body. Vagnus nerve simulators (VNS) are already used for treating epileptic seizures as they are considered by some “pacemakers for the brain”. Only now has this device been used to try to treat a patient in the vegetative state. 

As the team writes in their report, their unique findings directly contradict the general assumption that spending 12 months or longer in a vegetative state makes the condition irreversible.

before and after vns brain scans activity
Corazzol and Lio et al., Current Biology (2017)

The doctors recorded the patient’s responses to the stimulation provided by the VNS. Over the course of a month, they gradually increased the electric current supplied by the device. At the end of that month, when the device reached 1 miliampere,  the patient transitioned to a minimally conscious state. For the first time in 15 years he showed stable and registerable signs of consciousness.  “The man began responding to simple orders that had been impossible before. For example, he could follow an object with his eyes and turn his head upon request,” the team reported. 

“His mother reported an improved ability to stay awake when listening to his therapist reading a book.” 

This is all confirmed by the EEG and PET scan which confirm an increases and consistent activity in parts of the brain thought to be responsible for consciousness. 

“Brain plasticity and brain repair are still possible even when hope seems to have vanished,” says lead researcher Angela Sirigu

The team is now planning to begin a larger medical trial in order to further investigate the use of VNS as therapy for patients in vegetative states.

The findings were published in Current Biology