Neurophysiological Principles of Brain Stimulation in Pain Management

The mature human brain is capable to undergo substantial long-lasting functional and structural changes of neural pathways and synapses due to changes in behavior, previous experience, physiological demand, or injury. These changes are termed neuroplasticity. Neuroplastic changes can be adaptive, benefiting the organism, for example by facilitating recovery after injury, or maladaptive, contributing to the development and/or maintenance of various pathological phenomena, including chronic pain. Neuromodulation approaches, including brain stimulation methods such as Deep Brain Stimulation (DBS), epidural Motor Cortex Stimulation (MCS), repetitive Transcranial Magnetic Stimulation (rTMS) or transcranial Direct Current Stimulation (tDCS), in pain management build on growing evidence indicating that i) various neuromodulatory approaches can induce enduring alterations of neural activity and connectivity, and therefore can potentially reverse maladaptive neuroplastic changes co-occurring with chronic pain, and ii) a reversal of maladaptive neuroplastic changes in various chronic pain syndromes is indeed associated with pain relief.