Abstract
The correlation between the occurrence of the cerebrovascular disorders and the meteorologic factors was studied by application of the discriminant analysis.
The present study was accomplished on 235 patients with cerebrovascular accidents (83 hypertensive cerebral hemorrhages, 153 cerebral infarctions with hypertension) who were admitted to Yaeyama Prefectural Hospital from January 1982 to December 1984. The detailed meteorologic data, including air temperature, relative humidity and atmospheric pressure, at the time of the attack were analyzed in 63 cases with hypertensive cerebral hemorrhage and 93 cases of cerebral infarction whose diagnosis was established by CT scan. Remaining 19 cases with cerebral hemorrhage and 60 cases of cerebral infarction were used for external check.
The anaysis of the variables using a personal computer revealed that the following 5 items were most contributory to the the occurrence of the cerebral hemorrhage; (1) atomospheric pressure-yearly mean atmospheric pressure (<P) (2) air temperature-yearly mean air temperatutre (=T) (3) humidity-yearly mean humidity (=H) (4) maximum air temperature at the day of attack-maximum air temperature at the previous day (=Tmax) (5) maximum air temperature at the previous day-minimum air temperature at the day of attack (=Tmin). The discriminant formula (Y
H) was as follows; Y
H=0.008×P+0.014×T-0.002×H-0.004×Tmax-0.009×Tmin-0.235, The rate of correct prediction was 92% by internal check and 84% by external check. For the occurrence of the cerebral infarction, a significant seasonal variation was found.
