A 47-year-old woman was admitted to the hospital due to sudden severe headache. The patient presented with drowsiness initially, but soon manifested symptoms of vomiting and convulsions. She then became stuporous, with both pupils fixed at 6 mm. Brain computed tomography (CT) demonstrated subarachnoid hemorrhages in both cerebral hemispheres, a large intracerebral hemorrhage in the left Sylvian cistern area and an intraventricular hemorrhage (Figure 1). CT angiography (CTA) was attempted to locate a possible ruptured brain aneurysm; however, the contrast media was unable to penetrate the brain due to severe brain swelling, so it was impossible to evaluate the intracranial vessels. To reduce the intracranial pressure, an emergency decompressive craniectomy was performed. In addition to the severe brain swelling, a saccular aneurysm in the left middle cerebral artery was identified that was still actively bleeding. Thus, aneurysm neck clipping was performed. The surgery lasted for 3.5 hours, with norepinephrine administered because the patient's blood pressure could not be maintained. The patient's status worsened postoperatively, and she entered a coma, with pupils fixed at 7 mm. There were no notable changes other than a slightly changing pupil size, and her vital signs remained stable. However, movement, respiration, and brainstem reflexes were all completely absent.

Electroencephalography (EEG) performed on postoperative day (POD) 9 to delineate brain activity showed minimal continuous, irregular, and low-amplitude slow activity, and a neurologist confirmed the results as equivalent to brain death. Subsequently, the hospital's brain death review committee evaluated the patient's status and confirmed the diagnosis. Organ donation was recommended to the family, but they declined. Limb movements not seen before were observed on POD 15; the upper limb movements included bilateral arm flexion to the chest and shoulder adduction, similar to the Lazarus sign. The hands were not completely folded together, but instead came into close proximity (e.g., praying hands) before returning to the original position. At the time of the upper limb movements, the lower limbs also showed flexion and extension. The movements occurred intermittently for 15 to 30 seconds, and were observed 3 and 4 times a day. The times of day of occurrence and the factors causing the movements were unclear. When a painful stimulus was applied, such movements were sometimes seen to occur up to 5 times; however, these movements did not always occur in response to pain. With time, their frequency decreased, and the movements disappeared around POD 30.

On POD 40, a follow-up brain CT was performed, demonstrating a large cerebral herniation at the craniectomy site and decreased corticomedullary differentiation of the cerebral hemisphere (Figure 2), confirming the diagnosis of severe hypoxic encephalopathy. The patient remained vitally stable without any notable symptom changes until POD 219, at which time she had a drop in blood pressure and unstable vital signs; she was pronounced dead on POD 220. As her physical status continued without notable changes, we again recommended organ donation two or three times. However, the family refused organ donation stubbornly and asked to continue life-sustaining treatment, which prolonged the time until death. CT images were taken on POD 40, 65, and 142, but no other EEG tests were performed (Figure 3 and 4). Furthermore, basic neurological tests were performed three times a day at the intensive care unit (ICU) following the brain death diagnosis, but no other changes were observed. No reflexes had been observed since POD 30.

A 42-year-old man was admitted to our hospital with reduced consciousness and cyanosis after getting stuck in an escalator. Immediately after he was admitted to the hospital, cardiac arrest occurred. Cardiopulmonary resuscitation was performed, and spontaneous circulation was observed 15 minutes later. He was in a coma and limb reflexes were absent; bilaterally, the pupils were fixed at 6 mm. A brain CT examination showed no evidence of intracranial injury; however, hemopneumothorax was found, and right and left tube insertions were performed. Multiple rib fractures were observed on both sides, and the patient was admitted to the thoracic surgery ICU (Figure 5). An EEG performed on day 4 post-admission showed minimal continuous, irregular, and low-amplitude slow activities, verified as equivalent to brain death by a neurologist. His chest condition improved on day 7 post-admission, but the patient remained in a coma. Brain death was diagnosed, and he was transferred to the neurosurgery ICU for follow-up. Diffuse severe brain swelling with transtentorial herniation was found in the follow-up brain CT performed on day 9 post-admission (Figure 6). The Brain Death Review Committee evaluated the patient's status and confirmed the diagnosis of brain death. Organ donation was recommended to the family, but they refused. Beginning on day 10 post-admission, the Lazarus sign was observed. The patient showed upper extremity movements similar to the patient in Case 1, although without spontaneous and/or reflex movements in the lower extremities. The movements occurred irregularly for 15 to 30 seconds, and were observed 1 and 2 times a day. The times of occurrence and the factors causing the movements were unclear. The movements occurred until day 20 post-admission, after which they were no longer observed. The patient remained vitally stable without any notable symptom changes over several months. As seen in Case 1, the patient's blood pressure dropped and vital signs were unstable for about a day before the patient died; he was pronounced dead on day 117 post-admission. Other than the CT image taken on POD 9, no further CT or CTA imaging was performed. A follow-up EEG was performed on POD 88, but the results continued to indicate brain death. Since the diagnosis, basic neurologic tests were performed three times a day at the ICU, and no other changes were observed.