countries: Turkey (ranked 9 th), China (12 th), Brazil (15 th) and South Korea (18 th). The geographical analysis reveals: (a) continuous decline of North America's publication share from 46% in 1987 to 38% in 2007; (b) rising importance of the European share to over 46% in 2007, accompanied by an increasing prevalence of the European Union; (c) emergence of the Asian countries for a nearly 20% share of publications in 2007 largely from Japan, China, Taiwan and South Korea; (d) negligible presence of Africa (<2%) and (e) slow growth of South America from <1% in 1977 to <3% in 2007. Conclusion: The rapid evolution and explosion of pain research in the last 30+ years was accompanied by important changes in the landscape of the contributing countries and geographical regions.