Worldwide academic contributions of Japanese neurosurgeons.

Based on the data reported in the National Institute of Science and Technology Policy 2010, Japan is ranked in fourth place in the world in terms of the numbers of the articles in the fields of clinical medicine. However, there had not been any objective data regarding the numbers of publications by neurosurgeons. As it is important for neurosurgeons to realize the extent of academic contributions by the neurosurgeons in different countries, the numbers of publications in the major journals by the members of the Japan Neurosurgical Society and those from neurosurgical institutions around the world were analyzed using both the biomedical literature database PubMed and the publication database "ISI Web of Knowledge." Parts of the results were presented in the 69th Annual Meeting of the Japan Neurosurgical Society. As to the number of neurosurgical publications in English from the top 9 countries, the US has been consistently in first place and Japan in second. However, the number of publications from Japan has been decreasing since 2000. With regards to the "top 8 journals" such as the Lancet and the Journal of the American Medical Association, the number of first-author publications by Japanese neurosurgeons increased in the late 1980s and had been 2-9 articles per year until recently. In the "top 12 neuroscience journals" which include Stroke, Neuro-Oncology, Cancer Research, and others, Japan had been in the third next to the US and UK till 2004, but Germany surpassed Japan in 2005. In the "top 6 clinical journals" such as the Journal of Neurosurgery and Neurosurgery, the US has been consistently keeping first place and Japan second place since 1977. Searches using the key word elucidated that Japanese neurosurgeons are greatly contributing in the field of "aneurysm." Regarding the number of publications per neurosurgeon, Canada and UK are in the forefront and Japan is down to eighth place. Japanese neurosurgeons have been contributing greatly next to the Americans to the field of clinical neurosurgery and neuroscience by publishing in English. However, the number of publications by Japanese neurosurgeons has been declining since 2000. The Japan Neurosurgical Society must come up with countermeasures to address this problem.