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The Brain and the Perception of Chronic Pain and Stress: What Neuroscience teach Us

For the last fifteen years, our knowledge of chronic pain has begun to grow thanks to systematic research in the field of neuroscience. Thanks to neuroscience research, the involvement of our central nervous system in the creation, maintenance and experience of chronic pain is well documented and we begin to understand how pharmacological and psychological therapies improve chronic pain at a cognitive level. Below are some findings on this very interesting topic.

Several neuroscience studies have studied people with chronic pain at rest. When people do not do something specific then a network of brain structures called, the rest state network, are activated. This network is involved in daydreaming and in self-perception. In the case of people with chronic pain, changes were found in this network, leading to a more active state at rest in people with chronic pain in relation to people without chronic pain. This fact suggests that this network may be in a state of constant hyperactivity in chronic pain (Kucyi et al. 2014, Martucci et al. 2015). This network also appears to be affected when taking medications for chronic pain. For example, the analgesic effects of antidepressants appear to be due to the reversal of the hyperactivity of the resting-state network mentioned above (Jensen et al. 2014).

Other studies have focused at different brain structures and how they relate to pain, such as areas involved in motor and sensory processes (Kutch et al. 2015), fear processing (Jiang et al. 2016), reward and motivation (Berger et al. 2014), and in cognitive processes (Weissman-Fogel et al. 2011). In many of these studies it appears that the activity of structures that control cognitive functions reduces the perception of pain. For example, if structures of the prefrontal cortex are activated, which are involved in cognitive pain control, this may lead to reduced reports of pain (Seifert et al. 2009).

Neuroimaging has also explored the effects that psychological sessions have in chronic pain. Such therapies, for example, include cognitive behavioral therapy and stress reduction therapy. People with chronic pain often experience deficits in cognitive and emotional control, which are related to their experience of pain (Bushnell et al. 2013). That is, people are often so absorbed in pain that their brain is unable to control other cognitive processes. For this reason, many times decision-making processes are not so easy to implement or the management of stress is also difficult for people with chronic pain.