Recent concepts of pain.

Recent evidence shows that pain is not simply a function of the amount of bodily damage alone, but is influenced by attention, anxiety, suggestion, and other psychological variables. The gate control theory proposes than pain signals from the body are modulated by other, concurrent somatic inputs as well as by descending influences from the brain. It is now known that some kinds of pain can be diminished or abolished by anesthetic blocks of trigger points or by intense stimulation of the same points. These effects appear to be mediated by brainstem mechanisms that exert a tonic inhibitory effect on pain signals. Studies of paraplegic patients further elucidate the multiple neural interactions that occur in eliciting and alleviating pain. An example of interacting therapies for cancer pain is the significant augmentation of the effectiveness of the Brompton mixture by a psychologically supportive hospital environment.