Evidence from FPWR-supported studies shows that Vagus Nerve Stimulation (VNS) may reduce temper outbursts and other disruptive behaviors in individuals with PWS. With your support, FPWR is conducting a clinical trial of a VNS device to make this treatment available to our loved ones with PWS.
Temper outbursts and disruptive behaviors are among the most challenging aspects of PWS, both for the individual with PWS and their family. Affecting between 60 and 80% of people with PWS, temper outbursts are a major cause of family stress and have a detrimental effect on the quality of life of both the person with PWS and their family.
VNS uses brief electrical impulses to stimulate areas of the brain that are important for controlling emotions and behavior. VNS has been approved by the FDA to treat epilepsy and chronic recurrent depression. Now, evidence supports the use of VNS to reduce temper outbursts and improve disruptive behaviors in individuals with PWS. The approach has been studied in a small number of PWS individuals in the U.K., with a significant reduction in both the number and severity of temper outbursts.
VNS was both safe and effective in two small clinical trials
The potential benefits of VNS in people with PWS were first demonstrated using a surgically implanted VNS device, where two of three adult participants showed improvements in temper outbursts. The participant who showed no improvement had no prior history of temper outbursts. The two participants whose behavior improved asked to continue with the VNS after the study finished, and in an informal follow-up eight years later both individuals reported continuing benefits and no unexpected side effects. In one participant, the problem behaviors had recently returned to pre-VNS levels. It was subsequently discovered that the battery of the VNS had run out.
A second clinical trial using transcutaneous vagus nerve stimulation (t-VNS) also showed efficacy. The external device was worn for four hours each day with an electrode in the left ear to stimulate the auricular branch of the vagus nerve. Temper outbursts improved significantly in 4 out of 5 participants after six to nine months of t-VNS. Significant reductions in the number of temper outbursts were observed to the extent that they had no outbursts or, at most, the occasional very minor outburst. Reductions in scores on the Challenging Behavior Inventory (CBI) and improvements on global outcome scales were also noted. Qualitative informant interviews described the participants as showing improved cognitive flexibility and ability to control emotions, and an increased ability to manage unexpected change. No significant side effects were observed.
Ongoing VNS Research: VNS4PWS Clinical Trial
FPWR is conducting a multi-center VNS clinical trial in the U.S. with the aim of making this device available for our loved ones with PWS. The trial has completed enrollment, and the final few participants are completing the 9-month study.
Learn more about VNS for PWS in this recorded webinar with Drs. Theresa Strong, Lauren Schwartz, and Tony Holland.
