The Japanese experience in hemorrhagic stroke.

AIM

To review current problems with hemorrhagic stroke in Japan and to explore possible explanations for a change not only in the incidence but also the severity of hemorrhagic stroke in recent years in Japan.

METHODS

Mortality statistics, community-based registries and hospital records were used.

RESULTS AND CONCLUSIONS

The age-adjusted stroke mortality rate in Japan has declined over the last 20 years by approximately 75%, a very strong decline compared with other countries. The reduction was much more marked for hemorrhagic stroke than for ischemic stroke. Community-based registries for recent years show that the incidence ratio of brain infarction to brain hemorrhage is 1.5-4.0; this is about one-half, or even less than one-half of the rates reported in Western populations. The incidence of subarachnoid hemorrhage in Japan is 7-12% of total strokes. The growing popularity of antihypertensive treatment and changes in lifestyle, including nutrition, are considered responsible for the marked change observed in the stroke figures. Furthermore, mild to moderate cases of brain hemorrhage have been seen more frequently in recent years than severe cases.