Neuromodulation of cancer pain.

Managing cancer-related chronic pain is challenging to health care professionals as well as cancer patients and survivors. The management of cancer-related pain has largely consisted of pharmacological treatments, which has caused researchers to focus on neurotransmitter activity as a mediator of patients' perception of pain rather than the electrical activity during neurobiological processes of cancer-related pain. Consequently, brain-based pain treatment has focused mainly on neurotransmitters and not electrical neuromodulation. Neuroimaging research has revealed that brain activity is associated with patients' perceptions of symptoms across various diagnoses. The brain modulates internally generated neural activity and adjusts perceptions according to sensory input from the peripheral nervous system. Cancer-related pain may result not only from changes in the peripheral nervous system but also from changes in cortical activity over time. Thus, cortical reorganization by way of the brain's natural, plastic ability (neuroplasticity) may be used to manage pain symptoms. Physical and psychological distress could be modulated by giving patients tools to regulate neural activity in symptom-specific regions of interest. Initial research in nononcology populations suggests that encouraging neuroplasticity through a learning paradigm can be a useful technique to help treat chronic pain. Here we review evidence that indicates a measurable link between brain activity and patient-reported psychological and physical distress. We also summarize findings regarding both the neuroelectrical and neuroanatomical experience of symptoms, review research examining the mechanisms of the brain's ability to modify its own activity, and propose a brain-computer interface as a learning paradigm to augment neuroplasticity for pain management.