Transcutaneous cervical vagal nerve stimulation paired with traumatic script stress significantly decreased sympathetic function, including a 5.7% reduction in heart rate compared to sham, in patients with PTSD.
RCT (n=25)
Double-blind
Simple randomization
No
Does transcutaneous cervical vagal nerve stimulation reduce sympathetic responses to acute stress in patients with posttraumatic stress disorder?
Transcutaneous cervical vagal nerve stimulation significantly attenuates sympathetic arousal and cardiovascular reactivity to traumatic and mental stress in patients with PTSD.
Standardized Mean Difference: 0.43
p-value: p=<0.01
OBJECTIVE: Exacerbated autonomic responses to acute stress are prevalent in posttraumatic stress disorder (PTSD). The purpose of this study was to assess the effects of transcutaneous cervical VNS (tcVNS) on autonomic responses to acute stress in patients with PTSD. The authors hypothesized tcVNS would reduce the sympathetic response to stress compared to a sham device. METHODS: Using a randomized double-blind approach, we studied the effects of tcVNS on physiological responses to stress in patients with PTSD (n = 25) using noninvasive sensing modalities. Participants received either sham (n = 12) or active tcVNS (n = 13) after exposure to acute personalized traumatic script stress and mental stress (public speech, mental arithmetic) over a three-day protocol. Physiological parameters related to sympathetic responses to stress were investigated. RESULTS: Relative to sham, tcVNS paired to traumatic script stress decreased sympathetic function as measured by: decreased heart rate (adjusted β = -5.7%; 95% CI: ±3.6%, effect size d = 0.43, p < 0.01), increased photoplethysmogram amplitude (peripheral vasodilation) (30.8%; ±28%, 0.29, p < 0.05), and increased pulse arrival time (vascular function) (6.3%; ±1.9%, 0.57, p < 0.0001). Similar (p < 0.05) autonomic, cardiovascular, and vascular effects were observed when tcVNS was applied after mental stress or without acute stress. CONCLUSION: tcVNS attenuates sympathetic arousal associated with stress related to traumatic memories as well as mental stress in patients with PTSD, with effects persisting throughout multiple traumatic stress and stimulation testing days. These findings show that tcVNS has beneficial effects on the underlying neurophysiology of PTSD. Such autonomic metrics may also be evaluated in daily life settings in tandem with tcVNS therapy to provide closed-loop delivery and measure efficacy.ClinicalTrials.gov Registration # NCT02992899.
Gurel et al. (Tue,) conducted a rct in Posttraumatic stress disorder (PTSD) (n=25). Transcutaneous cervical vagal nerve stimulation (tcVNS) vs. Sham stimulation (0.2 Hz pulses, peak voltage 14 V) was evaluated on Heart rate response to traumatic script stress (adjusted β = -5.7%, 95% CI ± 3.6%, p=<0.01). Transcutaneous cervical vagal nerve stimulation paired with traumatic script stress significantly decreased sympathetic function, including a 5.7% reduction in heart rate compared to sham, in patients with PTSD.