This brainstem hemorrhage, as well as other severe cranial traumas or cerebral hemorrhages, if they cause a severe intracranial hypertension, will lead to a condition called stress ulcer, commonly known as Cushing's ulcer. This occurs because the increased intracranial pressure causes ischemia and hypoxia in the gastric mucosa, which then leads to localized, extensive necrosis of the gastric mucosa, resulting in upper gastrointestinal bleeding. This includes brainstem hemorrhages and many other cranial injuries and cerebral hemorrhages with intracranial hypertension as a very common complication. Therefore, it is due to the local ischemia of the gastric mucosa caused by increased intracranial pressure, leading to bleeding caused by gastric acid corrosion.