A new study finds that for some chronic pain sufferers, avoiding the harmful effects of stress may be key to managing their condition. As such, stress management techniques and relaxation or meditation training is highly recommended for individuals with chronic pain.
In a study that appears in the journal Brain, University of Montreal researchers say stress management is particularly important for people with a smaller-than-average hippocampus, as these individuals seem to be particularly vulnerable to stress.
"Cortisol, a hormone produced by the adrenal glands, is sometimes called the 'stress hormone' as it is activated in reaction to stress. Our study shows that a small hippocampal volume is associated with higher cortisol levels, which lead to increased vulnerability to pain and could increase the risk of developing pain chronicity," said researcher and doctoral student Étienne Vachon-Presseau.
As neuropsychologist Dr. Pierre Rainville said, "Our research sheds more light on the neurobiological mechanisms of this important relationship between stress and pain. Whether the result of an accident, illness or surgery, pain is often associated with high levels of stress.
"Our findings are useful in that they open up avenues for people who suffer from pain to find treatments that may decrease its impact and perhaps even prevent chronicity. To complement their medical treatment, pain sufferers can also work on their stress management and fear of pain by getting help from a psychologist and trying relaxation or meditation techniques."
In the study, researchers evaluated 16 patients with chronic back pain and a control group of 18 healthy subjects.
The goal was to analyze the relationships between four factors: 1) cortisol levels, which were determined with saliva samples; 2) the assessment of clinical pain reported by patients prior to their brain scan (self-perception of pain); 3) hippocampal volumes measured with anatomical magnetic resonance imaging (MRI); and 4) brain activations assessed with functional MRI (fMRI) following hot/cold pain stimulations.
Researchers discovered patients with chronic pain generally have higher cortisol levels than healthy individuals.
Data analysis also revealed that patients with a smaller hippocampus have higher cortisol levels and stronger responses to acute pain in a brain region involved in anticipatory anxiety in relation to pain.
The response of the brain to the painful procedure during the scan partly reflected the intensity of the patient's current clinical pain condition.
These findings support the chronic pain vulnerability model in which people with a smaller hippocampus develop a stronger stress response, which in turn increases their pain and perhaps their risk of suffering from chronic pain.
Experts say that the study supports stress management interventions as a treatment option for chronic pain sufferers.
