The Glasgow coma scale (GCS) was introduced as a scoring system for patients with impaired consciousness after traumatic brain injury (TBI). Since, it has become the worldwide standard in TBI assessment. The GCS has repeatedly been criticized for its several failures to reflect verbal reaction in intubated patients, and to test brain stem reflexes. Recently, the full outline of unresponsiveness (FOUR) score was introduced, which is composed of four clinically distinct categories of evaluation: eye reaction, motor function, brainstem reflexes and respiratory pattern. This study aims to validate the FOUR score in neurosurgical patients.