Non-invasive vagal nerve stimulation decreases brain activity during trauma scripts

Area of Science:

• Neuroscience
• Psychiatry
• Medical Devices

Background:

• Traumatic stress can lead to long-term neurobiological changes and psychiatric conditions like PTSD.
• Non-invasive vagal nerve stimulation (nVNS) is hypothesized to reduce sympathetic stress reactivity and alleviate trauma symptoms.
• Understanding nVNS's effect on neural responses to trauma is crucial for developing new therapeutic strategies.

Purpose of the Study:

• To investigate how nVNS influences neural activity in response to personalized traumatic scripts.
• To examine the impact of nVNS on brain regions associated with stress and emotional processing.
• To determine if nVNS can modulate sympathetic reactivity in individuals with a history of trauma.

Main Methods:

• A double-blind, sham-controlled study involving 19 participants with trauma history but no PTSD diagnosis.
• Participants were exposed to personalized traumatic scripts followed by either sham or active nVNS in sequential blocks.
• Brain activity was assessed using High-Resolution Positron Emission Tomography (HR-PET) with radiolabeled water to measure cerebral blood flow.

Main Results:

• Traumatic scripts activated several brain areas, including the prefrontal cortex, amygdala, and hippocampus.
• Active nVNS led to reduced activation in the prefrontal cortex, anterior cingulate, and insula compared to sham stimulation.
• Repeated exposure to trauma scripts with nVNS showed a shift from scene appraisal to cognitive processing.

Conclusions:

• nVNS effectively decreases neural reactivity to emotional stressors in key brain areas involved in stress response.
• The findings suggest nVNS may facilitate a cognitive shift in processing emotional events, offering a potential therapeutic avenue.
• nVNS demonstrates promise in mitigating the neural impact of trauma, warranting further investigation for PTSD treatment.