Inclusion Criteria:  Adult ED patients with a decreased level of consciousness (verbal, pain, or unresponsive using the AVPU scale, and a GCS-E score of less than 4) who have stayed at the ED for less than 12 hours at the time of enrollment.  Exclusion Criteria:  Patients with the difficulty of applying EEG due to head trauma or skull deformities. Patients for whom standard treatment may be significantly delayed by applying the EEG device. Patients with a guardian who do not agree to enroll in this study.