Two Central Pathways for Pain

Abstract

Goldscheider [6] first described two forms of sensation which were both described as ‘painful’. In addition to ample confirmation of the observation, more recent publications (e.g. Sinclair and Stokes [18]) have stressed that so-called first pain, which is in fact pinprick sensation, is carried by peripheral Aδ fibres; it may be added that it is a purely cutaneous sensation. Second or slow pain, which is real or tissue damage pain, is transduced by polymodal nociceptors (distributed throughout many deep tissues as well as skin) associated with unmyelinated (C) primary afferent fibres [10, 19]. These mechanisms have been reviewed by Mumford and Bowsher [14].