The Vagus Nerve – A Jack Of All Trades

Researchers in Texas are developing a therapy for a whole range of neurological diseases – including spinal cord injuries. Their focus is a nerve with truly astounding capabilities. The Wings for Life Foundation significantly supports these studies with money raised by the Wings for Life World Run.


The vagus nerve is the most fascinating nerve in our body – and plays a key role in the treatment of spinal cord injuries. Professor Michael Kilgard has discovered a way to utilize its capabilities. After taking part in his clinical trial, the first spinal cord injury patients have regained improved movement of their hands. The beginning of a revolutionary therapy approach.

Are you familiar with the vagus nerve? It runs from the brain, through the neck, and into the abdomen. As one of the longest nerves in the body, it automatically regulates vital functions such as heart rate and digestion. Unlike motor nerves, which we utilise for movement, the vagus nerve cannot be actively influenced. The exciting aspect is that, if stimulated during therapy by targeted electrical impulses, it is capable of forming new nerve connections – which, in the best-case scenario, enables movement.

A new era of nerve therapy

The vagus nerve is easily accessible from the outside, which renders it a highly attractive option for the treatment of neurological diseases such as epilepsy or tinnitus. Professor Kilgard has tapped into this very fact. Over the past 25 years, he and his team at the University of Texas in Dallas have been researching the nerve’s special abilities. Michael Kilgard is a pioneer in the field of vagus nerve stimulation, VNS for short, and has made some truly groundbreaking discoveries. “The reason we’re confident that vagus nerve stimulation is going to work, is that the pairing of VNS with physical therapy already worked in clinical trials that were conducted in individuals with ischemic stroke,” says Kilgard.

A stroke and a spinal cord injury seem to have little in common at first glance, yet a crucial correlation exists. In both cases, neurons in the central nervous system are impaired or disrupted. Depending on the severity of the injury, patients have limited ability to move their hands, arms, and legs, among other symptoms. “We established that vagus nerve stimulation is also effective in treating spinal cord injuries in preclinical models.And we’ve been interested in developing devices to help people restore their own ability to control their arms and legs.”

We established that vagus nerve stimulation is also effective in treating spinal cord injuries. And we’ve been interested in developing devices to help people restore their own ability to control their arms and legs.

HOW VAGUS STIMULATION WORKS

Kilgard and his team have vastly modernised VNS. In the past, it was necessary to wrap electrodes around the nerve. A stimulation device had to be implanted at chest level and connected to the electrodes. Today, a minuscule chip replaces the outdated wire electrodes and bulky stimulator. The procedure takes only 30 minutes and is gentler on the patient.

A band worn around the neck supplies the chip with energy. During therapy the stimulator is switched on and gentle electric shocks are transmitted to the brain via the nerve. This stimulates the regions responsible for learning new movements, for example. Then something truly remarkable occurs. Researchers call it plasticity*. The brain learns that it needs to modify its circuits and access intact pathways in order to trigger certain movements. “Stimulating the vagus nerve while you practice things, triples the number of connections that are made. This ability to strengthen the number of new connections, helps people recover better and faster from spinal cord injury,” the neuroscientist affirms.

Hope for spinal cord injury patients

What impact do all these technical advances have in practice? This is where the crucial next step comes in: the application in patients. Among the first to benefit from VNS are patients suffering from incomplete spinal cord injuries, as in the case of Amanda. She was involved in a car accident in 2015 and has been paralyzed ever since: “Thankfully I’ve gained quite a bit back. I have great arm movement, but obviously these hands – they don’t do much.” Amanda is one of a total of 19 participants in Michael Kilgard’s clinical trial in Texas: “I decided to be part of the study because it just made sense, and it seemed the least invasive treatment option. I personally have seen great results with it,” the American says.

The study participants were each treated over a period of 36 days. They were asked to perform activities that pose problems for them in everyday life, such as buttoning a shirt, tying shoes, or pressing buttons. “We are working with games on tablets, where patients are required to press buttons or perform certain movements,” says Kilgard. Meanwhile, the stimulator is activated via an app to transmit signals to the brain. These signals strengthen the nerve connections. “The movements subsequently increase in strength and the patients’ game high score rises, which increases their motivation to continue training,” the study supervisor reports.

Breakthrough in therapy

The path from basic laboratory research to clinical application in patients is both long and challenging. This makes the fact that Dr. Kilgard’s team was able to successfully complete the study all the more significant. The publication of the results is highly anticipated. Are the findings significant and the therapy therefore effective? “The results remain unpublished, but yes, they are positive,” says the Texan. Patients actually improved their ability to grasp objects, and the researchers noted a marked improvement in hand function. “It’s fantastic, right? This has been 25 years in the planning. Working with all these 19 participants, they all signed up to be the very first people to ever receive this device – it was a daring adventure for them. And so, each person is an interesting story to me. We’re really looking forward to moving from the current 19 to 1,900 patients in the future,” the neuroscientist proudly announces. Following successful approval, the therapy could be available in just a matter of years and provide relief for many patients. It would then even be possible for individuals to conveniently use the device at home after a brief procedure in a clinic.

The clinical study demonstrates the enormous potential of vagus stimulation. It harbours genuine hope for those affected and has the power to sustainably improve their quality of life. Kilgard and his team are working tirelessly to improve walking, bladder, and bowel functions next. The aim is to enable people with spinal cord injuries like Amanda to lead a more independent life: “My biggest hope, I guess, is just to get back to being independent in all ways – and I am definitely getting there.”

Wings for Life already funded the preceding project and the clinical study by Professor Michael Kilgard with a total of 1.1 million Euros. Thank you for making such projects possible with your donations and helping us find a cure for spinal cord injuries.

*Neuronal Plasticity

The architecture of our brain and spinal cord changes daily. New experiences or impulses form new connections between nerve cells. Existing pathways are expanded, while unused ones are reduced. This ability to rewire nerves is called neuronal plasticity. Without it, we would not be able to learn new skills.

You want to know more about the topic? Watch the video below: