[Brain death in a neurosurgical unit in Japan].

Walker states that the incidence of brain death accounts for approximately 1% of all deaths, so that brain death is a common state. According to Jennett et al, the occurrence of brain death is now a relatively frequent event, with about 4000 cases each year in Britain. But the actual circumstances of brain death can not be discovered from any published report. During the last 11 years (1973-1983) at Kyorin University Hospital, we studied 121 cases diagnosed as brain death according to Japanese criteria. The Japanese criteria requires that the pathology be a gross primary brain lesion, so did not concern ourselves with brain deaths due to secondary brain damage. We analysed the factors associated with brain death, that is the annual incidence, age, sex distribution, primary diagnosis and elapsed time from brain death to cardiac death. The increasing incidence of brain death in the last 5 years is probably due to a rise in severely brain-damaged patients (Table 1). In the age distribution, the high number of patients in their fifties presumably reflects the human age tendency for traumatic and vascular disorders respectively (Fig. 1 and Table 2). The fact that males predominate relates to the greater risk faced regarding cerebral trauma (Table 3). The primary diagnoses were cerebrovascular accidents in 60% of the cases especially subarachnoid hemorrhage in 41%, head injury in 31% and brain tumor in 9% (Tables 4 and 5). The elapsed time from brain deaths is measured from diagnosis of clinical brain death to cardiac asystole (Fig. 2). All patients had final cardiac asystole while still being ventilated.(ABSTRACT TRUNCATED AT 250 WORDS)