Figure 3.

(A) Top 10 countries in terms of number of degenerative cervical myelopathy (DCM) research papers published. Japan was dominant in the first decade, publishing 32% to 56% of total papers each year. In the second decade, Japan’s output was frequently 30% or less of total international output. (B) Top 5 countries by number of patients studied. Japan and the United States were consistently the top 2 countries in terms of number of DCM patients studied each year. The relative dominance of the United States in 2007-2009 was due to a peak in number of patients studied in US studies.