Pain is complicated, not only because of the different types of it but also because of the multidimensional aspects of the physical, emotional and cognitive experience. However, in Understanding Pain, Fernando Cervero provides an updated scientific account that effectively covers the mechanisms involved, current methods of measuring and relieving pain in animals and humans, and the way it influences life on an individual as well as a societal level. He integrates historical background, cultural narratives, case histories and personal experience to paint a clear picture of the subject.
Cervero’s passion and scientific knowledge, as well as his logical design of the book’s building blocks, will help readers to shape their own ideas and think about pain more widely. This is an enjoyable and thought-provoking work, written in an accessible style that will be welcomed by those who are interested in the discipline of pain and have some background knowledge in neuroscience.
He begins the journey by explaining that a brief painful response to a simple injury is a “good” pain that protects us from harming ourselves, and that pain owing to inflammation helps us to heal, whereas abnormal pain caused by damage to the nervous system (neuropathic pain) is bad and difficult to treat. He then describes our current ways of measuring pain in experimental animals as unsatisfactory, criticising the methods of evaluating withdrawal reactions to external stimuli as expressions of a simple spinal reflex, rather than a sensation similar to the human experience. Measuring pain in humans is also tricky because no objective way of doing so yet exists, so we have to rely on subjective ratings by sufferers. However, studies seeking novel approaches to assessing pain in animals and objective methods of measuring it in humans, such as brain imaging, are promising.
Cervero walks us through the physiological processes that lead to pain sensation and its amplification, plus various types of pain, including the abnormal chronic neuropathic pains he rightly characterises as “enigmatic and dreadful”. He cautions that although we have learned a great deal, there is still a long way to go in the study of pain mechanisms, from the first spinal cord relay to complex perception involving the brain. Why do only a small proportion of individuals develop chronic pain after similar physical damage? The answer is unclear, but may depend on the individual’s genetic make-up, the environment and the way our emotions and rational thoughts influence the final pain experience.
Pain has always been with us, but with scientific advancement and the availability of analgesics, as well as changes in political and social views that have led to our seeing pain relief as a fundamental human right, we seem to be getting closer to a pain-free world. Cervero writes: “We have to accept that there will always be a certain amount of pain around us, but we strive to decrease its effects on our lives.” As he discusses, there is an interesting distinction in pain exposure between developed and developing countries. Whereas pain is a commonplace in developing countries, healthy people in today’s developed world are exposed to little of it. Unfortunately, our growing demand for a pain-free life has led to reduced pain tolerance and a vicious circle of pain relief. And there are still some forms of pain that lack effective therapy. This is the end of the tale, but not the end of the quest for better analgesics and a pain-free world.
Understanding Pain: Exploring the Perception of Pain
By Fernando Cervero. MIT Press, 192pp, £17.95. ISBN 9780262018043. Publication 12 October 2012