Vagus nerve stimulation helps PTSD patients in the long term

In a first-of-its-kind clinical trial, scientists from the University of Texas at Dallas and Baylor University Medical Center have shown that patients with treatment-resistant PTSD experience symptom relief within six months of receiving conventional therapy combined with vagus nerve stimulation (VNS).

The results of the phase 1 study on nine patients, conducted by scientists from the University of Texas Health Science Center for Biomedical Devices at the University of Dallas in collaboration with researchers from Baylor Scott & White Research Institute, are published in the journal Brain Stimulation.

Dr. Michael Kilgard, professor of neuroscience in the School of Behavioral and Brain Sciences, says the findings highlight the potential of this approach.

“In trials like this, some subjects usually get better, but they rarely escape a diagnosis of post-traumatic stress disorder. Typically, most have that diagnosis for the rest of their lives,” says Kilgard. “In this case, we got 100 percent recovery from the diagnosis. That’s very promising.”

Prolonged exposure therapy, a component of traditional PTSD treatment, is a form of cognitive-behavioral therapy conducted in a safe and supportive environment that involves gradually confronting people with thoughts, memories and situations they have avoided since experiencing the trauma.

In the study, researchers combined this therapy with the simultaneous delivery of short pulses of vagus nerve stimulation using a small device implanted in the participant’s neck. After a standard course of therapy consisting of 12 sessions, four evaluations were conducted at six months post-treatment. The effects persisted throughout this time in all nine participants.

According to Kilgard, the study is the largest clinical trial to date using an implantable device to treat PTSD.

The researchers’ groundbreaking work has previously demonstrated that VNS combined with physical rehabilitation can accelerate neuroplasticity – the remodeling of areas of the brain. Their 13-year effort to treat a wide range of conditions with VNS led to FDA approval for the treatment of upper extremity movement disorders in stroke patients.

The National Center for PTSD, part of the Department of Veterans Affairs, estimates that 5% of U.S. adults suffer from PTSD in any given year, and women are twice as likely to develop PTSD at some point in their lives. Many patients with PTSD do not respond to therapy or pharmacologic intervention, experience intolerable side effects, or experience relapses, leaving them with little hope for remission.

Kilgard emphasized that patients with PTSD are not only common among military veterans, but also among ordinary citizens who have faced traumatic events.

“When you hear ‘PTSD,’ you picture a war zone, but it’s much more widespread. It can be triggered by any event that instills fear of death or bodily harm, or the death of a loved one.

More than a decade ago, Dr. Robert Rennaker, professor of neurology and Texas Instruments Distinguished Chair in Bioengineering, began developing an innovative implantable device for VNS that would be much smaller and less expensive than devices already on the market. The most recent wireless version of the device is about the size of a coin.

The 49 people in the Dallas area who have already been fitted with these devices have a combined 100 years of experience with their implantation.

There have been no problems; all the devices still work. And they don’t interfere with routine medical care: you can get an MRI, CT scan or ultrasound with them.

The VNS  has “changed the game” by improving both the effectiveness of treatment and its tolerability.

The gold standard of treatment for PTSD yields about 85% response rates, 40% recovery from diagnosis and 20% treatment discontinuation. It will soon be possible to use VNS in people who are not helped by cognitive-behavioral therapy alone.