According to the World Health Organization (WHO), only a few countries such as Pakistan and Romania do not recognize brain death as human death. In Japan, while the Organ Transplant Law in enacted, brain death is acknowledged as human death only when a transplant is to be performed.
This interpretation remains unchanged, even after there revision of the Act.

"Brain Death" refers to a condition in which the functions of the entire brain, including the brain stem that controls respiration, are irreversibly lost due to occurrences such as head trauma and cerebral apoplexy. The advent of respirators made it possible to temporarily maintain the heart beat even after the loss of cerebral functions, but the heart will eventually stop beating in a few days.

The "vegetative state" is a condition in which all or some of the cerebral functions are lost and the patient loses consciousness. However, the functions of the brain stem remain, spontaneous respiration is possible in many cases, and sometimes recovery occurs. Therefore a vegetative state is fundamentally different from brain death.

Brain death will only be declared if organic injury is observed in the brain with attributable cause and if the following criteria are met:

  1. Deep coma
  2. Dilated and fixed pupils
  3. Loss of brain stem reflex
  4. Flat brain waves
  5. Loss of spontaneous respiration
  6. Two or more doctors with requisite expertise and experience confirm no changes after a second test conducted six or more hours later.
    (24 hours or more for children between the ages 12 weeks after birth to under 6 years)

Brain death cannot be declared in persons with drug intoxication, low body temperature, or endocrine/metabolic diseases. This evaluation is considered to be medically certain.

However, when respirators are used to maintain respiration and blood flow or when spinal reflexes cause movement in the limbs, brain death may be difficult to evaluate for Japanese who have recognized heart arrest (confirmation of the three signs: 1. Cessation of heart beat; 2. Cessation of spontaneous respiration; and 3. Loss of light reflex/dilated pupils) as human death.

In Japan, brain death is still not widely accepted as human death. Whether one considers heart arrest or brain death to be the benchmark for human death is a matter of personal judgement-- a decision based on personal views regarding life and death. Therefore, it is important for families to have serious discussions and express their intentions regarding this issue.