Fig. 2.
Neuroinflammation is associated with various insults that evoke painful sensations. These insults include but are not limited to trauma, major surgeries, drug treatments, autoimmune disease conditions, and other painful insults and tissue damage. Some of these insults such as major surgeries (breast surgery, amputation, thoracotomy), chemotherapy, and antiviral treatment will cause nerve injury, as highlighted in red. Others will cause immune activation (highlighted in purple) and tissue injury (highlighted in light blue). Neuroinflammation results in several adverse effects, such as chronic pain and neurodegenerative diseases including Alzheimer disease (AD), Parkinson disease (PD), multiple sclerosis (MS), and stroke. Neuroinflammation is also associated with chronic overlapping pain conditions. After priming of the nociceptive circuit by previous injury, stress, or existing genomic, environmental, and psychologic factors, acute insult may cause transition from acute pain to chronic pain. CNS = central nervous system.