Foreword

More than 2000 years ago, Epicurus (341–270 BC) stated that the pursuit of pleasure and absence of pain is the purpose of life. Thus, preventing or removing pain is one of the most beautiful and important aspects of life. Pain has been defined as an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage [1]. Essentially, it means that when treating pain, both the sensory (1⁄4painfulness) and emotional (1⁄4suffering) components need to be addressed. Pain physicians are very competent in treating acute pain, usually related to actual tissue damage, yet when it comes to chronic pain, which is mostly neuropathic or fibromyalgic, the underlying pathophysiological mechanisms may be different and can be considered a centrally controlled imbalance between pain input and pain suppression [2] requiring an alternative approach.