New Method to Assess Stress Shows Promise

Researchers at Wake Forest Baptist Medical Center have found a new way to understand and potentially help reduce stress symptoms.

Their approach focuses on the source of the body’s stress responses and whether the response is mostly mediated by the sympathetic or parasympathetic nervous system.

Stress responses are managed by the brain. Prior research shows the right side of the brain is involved with sympathetic responses, while the left side is associated with parasympathetic responses.

The sympathetic nervous system mediates the fight-or-flight stress response, and creates almost instant physical reactions, such as increased heart rate and blood pressure, changes in attention, memory, and other bodily functions.

However, if a threat or trauma is especially severe, prolonged or overwhelming, stress can also manifest as a freeze response. This is mediated by the parasympathetic nervous system, with physical reactions opposite of fight-or-flight.

To evaluate sympathetic versus parasympathetic nervous system influences on the cardiovascular system, researchers can measure the downstream effects through recordings of blood pressure and heart rate.

“Greater understanding of the close relationship between the brain and the heart is vital to identifying better ways to manage stress. This study suggests a simple method to evaluate central pathways in the brain that are involved in such stress responses,” write the researchers.

Lead researcher Charles H. Tegeler, M.D., professor of neurology at Wake Forest Baptist, and his team, conducted five-minute recordings of heart rate and blood pressure in 131 study participants to evaluate the effects of the autonomic nervous system on the cardiovascular system.

Then, for three minutes, the researchers conducted scalp recordings of the participants’ temporal lobe brain electrical activity.

To do this, they used a method called high-resolution, relational, resonance-based electroencephalic mirroring (HIRREM). For a one-minute segment recorded with eyes closed, their brainwaves were analyzed to identify electrical asymmetry.

The findings revealed that, among study participants with asymmetry in temporal lobe high frequency electrical activity, those with right compared to left side asymmetry had higher resting heart rates and other differences. These suggested the cardiovascular system may be less adaptable to shifting circumstances.

Researchers say the findings are important because persistent stress is likely responsible for a wide range of health and behavioral conditions.Such data may reveal better strategies to treat associated symptoms.

The study is published online in the journal Brain and Behavior.

Source: Wake Forest Baptist Medical Center