Offset Analgesia: At the Crossroads of Pain Modulation and Chronicity

Offset analgesia was first described in 2002 as a disproportionate decrease in perceived pain intensity following a slight incremental decrease in noxious stimulus intensity. Ever since, it has attracted much attention, both for the insights that it can provide into nociceptive processing mechanisms as well as for its clinical relevance to chronic pain. Together with conditioned pain modulation, assessment of offset analgesia has become a key psychophysical paradigm for the evaluation of endogenous pain modulation. Robert Coghill will first provide an overview of the mechanisms supporting offset analgesia and delineate its role in temporal filtering of nociceptive information. Second, Marieke Niesters will discuss the clinical relevance of offset analgesia, with particular focus on how offset analgesia is disrupted during neuropathic pain, and how offset analgesia can be pharmacologically modulated by a variety of analgesic drugs. Lastly, Jiro Kurata will address the involvement of offset analgesia in reward mechanisms as well as descending modulatory systems using evidence derived from neuroimaging studies of both healthy individuals and chronic pain patients. Together, all speakers will address the potential utility of offset analgesia in diagnosing/evaluating chronic pain and how it may serve as a marker for chronic pain.