When illusion becomes reality
Candy McCabe · Lara D. Veeken · 2011
Ameliorating the effects of chronic pain via visual manipulation This editorial refers to Analgesic effects of multisensory illusions in osteoarthritis, by Catherine Preston and Roger Newport, doi:10.1093/rheumatology/ker104, on pages 2314–2315. The purpose of pain is to alert us to threatening or damaging stimuli (potential or current) and simultaneously to move us to a place of safety. In order for this protective mechanism to work effectively, it requires integration between the sensory-discriminative component of pain and the evaluative effective-motivational component. When one of these is compromized, pain may become an inert sensation with loss of its warning quality. For example, people with pain asymbolia perceive the location and nature of the painful stimulus but do not interpret it as threatening; they actually laugh at the experience. Conversely, when the sensory-discriminative component is lost and painful stimuli are not detected, as in congenital analgesia, life-threatening damage can be inflicted without pain ever being experienced [1]. These two examples tell us that it is entirely possible to live in a pain-free world (albeit with potential negative consequences), and yet chronic pain continues to be one of our largest and costliest global health-care challenges [2]. Traditional therapies for chronic pain commonly provide minimal long-term benefits; technological advances in both spinal and cortical neuromodulation hint at the emergence of more invasive approaches for the future. But informed by our knowledge of pain asymbolia and congenital analgesia, are there perhaps other ways that we can relieve chronic pain?