Interpretation of a grimace response to painful stimuli as the best motor response of the Glasgow Coma Scale in comatose patients

Abstract

We investigated the relation between grimace for painful stimulation and best motor response (M) in Glasgow Coma Scale (GCS) in patients with comatose state. We recorded 51 total GCS scores from 43 patients with comatose state from patients transported to the emergency room or admitted to the emergency ward of Shizuoka Red Cross Hospital. We delivered painful stimulation to all of 43 patients (51 records) on sternum and fingernail bed (or inside of the arms). Grimace was observed more frequently along with M5 than with each of M1 – M4 (p<0.01) Both of intracranial and extracranial diseases showed high percentages of grimace positive in M5, however , grimace was also positive at M4 or lower level of best motor response only with extracranial diseases. The results suggested that grimace for painful stimulation might be equivalent to M5 in comatose state, especially in patients with intracranial diseases and might show that grimace is useful as an indicator in assessing the revel of consciousness. We concluded that grimace might be an alternative criterion of M5 level in case of difficult situation to examine due to traumatic injury or fixation with many vital monitors in extremities.