[Two cases in which the presence of ciliospinal response led to indecisiveness in the evaluation of brain death].

The ciliospinal reflex was first described by Budge in 1852. This reflex is used as an indicator of brain stem and autonomic nervous system functioning. In the Japanese guideline for determining brain death, the absence of this reflex is considered essential. We reported two cases in which the ciliospinal responses judged to be present resulted in the authors' indecision in determining brain death. They were the cases of a 74-year-old woman who suffered a right putaminal hemorrhage and that of a 28 year-old male with severe head and cervical cord injury. Although brain death was suspected in both cases from its clinical courses, the fact that the ciliospinal reflex was present in each case kept us from declaring that these patients were in the state of brain death. The center of the ciliospinal reflex lies in the first three segments of the thoracic spinal segments and two pathways are involved in this reflex. A noxious stimulation to the face will be registered through the brain stem, but if stimulation is in the neck or upper trunk, it may go directly to the spinal center. Because of the latter pathway to the spinal center, this reflex might remain in patients in whom the brain stem is completely nonfunctioning. Therefore, the presence of this reflex dose not always preclude a state of brain death.