An update on pain physiology: the relevance of Craig's and Jänig's hypotheses for hypnotic analgesia

The aim of the present review is to discuss two interesting hypotheses that explain the pathophysiology of pain: (1) Arthur Craig's hypothesis that the experience of pain, elicited by specific sensors projecting into the central nervous system through afferent pathways, is relevant for homeostasis and represents a specific emotion related to a homeostatic behavioural drive; and (2) Wilfrid Jänig's hypothesis that, in functional chronic pain syndromes, specific changes occur in autonomic, endocrine and somatic motor systems interactions which, then, result in dysregulation involving peripheral, spinal and brain mechanisms. Theoretically, on the basis of these two hypotheses, hypnotic suggestions for analgesia can affect pain at multiple levels, including its generation at the periphery, secondary sensory neurons sensitization, and modulation of endocrine/immune responses through the modulation of autonomic activity.