High incidence of acute traumatic spinal cord injury in a rural population in Japan in 2011 and 2012: an epidemiological study

Study design: Retrospective questionnaire-based epidemiological study. Background: Physicians treating acute traumatic spinal cord injury (SCI) in Japan noticed an increased occurrence of cervical SCI without skeletal injury. Objective: To elucidate the precise epidemiology of acute cervical SCI with the aim of planning a prevention program. Methods: Questionnaires were posted to all hospitals in Tokushima prefecture (around 780000 inhabitants) to investigate the annual incidence of SCI in 2011 and 2012. Results: The response rate was 79% in 2011 and 64% in 2012. The returned questionnaires reported on 95 patients in 2011 and 91 patients in 2012, with a mean age of 67.6 and 64.3 years and an annual incidence (per million population) of 121.4 and 117.1, respectively. More than two-thirds of the cases suffered cervical SCI without skeletal injury, and 61% of these were categorized as Frankel D neurological deficits due to low-energy impact as the main cause. Conclusion: The incidence of incomplete cervical SCI does appear to be increasing, and significant regional differences in the incidence of cervical SCI exist across Japan. We speculate that factors other than age are contributing to this increase.