Radiation effects on the incidence of stroke in atomic-bomb survivors

Summary

Stroke is a leading cause of death and disability worldwide. Although stroke has been induced by exposure to high-dose radiation to brain, head, and neck regions by radiotherapy, there is conflicting evidence whether sub-therapeutic irradiation is associated with stroke incidence or mortality. Previous studies on atomic bomb survivors have suggested radiation effects on stroke that differ among subtypes, but some uncertainty exists regarding diagnostic accuracy and ambiguous subtype classification. In this study, we will secure diagnostic and classification accuracy by reviewing charts according to pre-defined diagnostic criteria. The association between radiation and incidence of stroke and its subtypes (cerebral infarction, intracerebral hemorrhage, and subarachnoid hemorrhage) will be analyzed based on diagnoses confirmed from chart review.