Pain is a subjective feeling that can be influenced by sensory, affective, and cognitive factors. Chronic pain can have a widespread impact on overall brain function, and both cognitive and psychological factors play key roles in the development and management of pain.

Patients with long-term pain often present structural and emotional impairments associated with cortical regions of the brain that are linked not only to pain itself, but also to the many co-morbidities that often develop in association with chronic pain: depression, anxiety and sleep disturbances, for example.

Patients with chronic pain may require long-term pharmacological treatment; this entails a number of drawbacks mainly due to the undesirable side-effects that often arise with a continued use of analgesic drugs. There is a constant search for better pain management options, including non-pharmacological approaches. In the last decades, neurofeedback has been gaining ground as a potentially successful option.

What is neurofeedback?

Neurofeedback is a form of biofeedback. Biofeedback was born from the observation that one can control and manipulate certain bodily functions by being aware of them. By using instruments that measure physiological activity such as heartbeat, breathing, muscle activity, or skin temperature, a subject can receive fast and accurate information regarding those functions. The use of these monitoring systems allows the perception of the physiological functions, and in turn, and along with changes in thinking, emotions, and behavior (and adequate training), this allows the manipulation of those functions.

Biofeedback is widely applied to processes associated with the autonomic nervous system, such as heart rate, breathing rate or muscle tone. Biofeedback may be used to control those processes, and to improve health and physical performance. Over time, these changes can become long-lasting, enduring even without the continued use of monitorization instruments.

In the case of neurofeedback, these biofeedback techniques are applied to the brain. Neurofeedback, also known as EEG-biofeedback, uses electroencephalograms (EEG) to monitor brain waves, producing a signal that can be used as feedback to learn how to self-regulate brain functions. Lately, other monitorization techniques have begun to be applied, namely functional magnetic resonance imaging (fMRI) biofeedback.

It has actually been known for decades that, with adequate training, brain waves can be controlled. Intellectual activity induces fluctuations in cerebral bioelectric activity that can translate into neurophysiological changes. By understanding the association between the bioelectric activity of different brain areas and the associated cognitive, emotional, behavioral, or even pathological processes, neurofeedback can allow the modification of those specific processes.

Neurofeedback has proven useful in inducing relaxation and attention, in enhancing creativity, and as a therapy for a number of contexts – sleep disorders, epilepsy, depression, anxiety, language processing, neurorehabilitation in stroke, or enhancement of perception and learning. Another context in which neurofeedback has shown interesting effects is chronic pain.

Neurofeedback and pain management

Neurofeedback can have a direct influence on the processing of pain. By learning self-regulation of brain functions, a patient can modify the electrical activity of areas of the brain involved in pain processing, pain perception, or pain memory. This allows the reduction or even elimination of pain, along with many of its co-morbidities, including depression or anxiety, for example.

The psychological factors that influence pain perception have the ability to modify our body’s biochemical processes. Thoughts can have a direct impact on these processes and potentially produce analgesia. In fact, there is evidence indicating that cognitive control of pain can have a direct effect on opiod activity, stimulating the production of endorphins.

Another mechanism through which neurofeedback can modulate pain is the regulation of the emotional component of pain. The frontal cortex is associated with the feeling of unpleasantness associated with pain, and neurofeedback training applied to this region of the brain has been found to be able to induce changes in pain affect in patients with acute and chronic pain syndromes, leading to an increased pain tolerance.

Chronic pain can also induce changes in the functional organization of the brain. Neurofeedback can allow the control of pain by altering the connectivity between brain regions, thereby inducing long-lasting changes in neuronal networks that can counterbalance the changes induced by chronic pain.

Indeed, clinical data has demonstrated the efficacy of neurofeedback therapy in a number of chronic pain conditions: it can decrease headache intensity, being particularly effective in children and adolescents, as well as migraine and pain associated with fibromyalgia. Neurofeedback can also be effective in post-operative pain and in cancer pain.

During the last decades, neurofeedback training approaches and protocols have been steadily improving, along with its efficacy. As new methods arise, it is likely that neurofeedback can gain awareness and importance as a non-pharmacological therapy for a multitude of disorders. fMRI imaging, for example, can be a great upgrade for this therapy by allowing the detection of brain areas affected by chronic pain, and consequently allowing a more targeted intervention.

If one can learn to directly control the activation of specific brain regions, one can potentially be able to control neurophysiological mechanisms that may help in the treatment of disease.

References

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