- The subject population that will be included in the NIS are the consecutive discharged patients ≥18 years old who were hospitalized to Neurosurgical departments. Those whose Glasgow Coma Scale (GCS) ≤10[4] within 24 hours of lesion/admission will be defined as critically ill patients. Three kinds of cases will be included: brain trauma critically ill patients, cerebral haemorrhage critically ill patients or postoperative brain tumour critically ill patients.