Which of the following is NOT a component of the Glasgow Coma Scale?

The Glasgow Coma Scale (GCS) is a neurological scale used to assess a patient's level of consciousness after a brain injury. It comprises three main components: eye response, verbal response, and motor response. Each of these components evaluates different aspects of consciousness and neurological function.

Eye response evaluates how well a patient’s eyes react to stimuli, ranging from no response to spontaneously opening eyes. Verbal response measures the patient's ability to communicate verbally, which can indicate cognitive function. Motor response assesses the patient’s physical movements in response to commands or stimuli, which provides insight into motor function and brain responsiveness.

While pain tolerance might relate to a patient’s overall state, it is not a defined criterion within the Glasgow Coma Scale. Instead, pain response can be assessed through the motor response component by observing how a patient reacts to painful stimuli. Therefore, since pain tolerance does not fit the established categories of the GCS, it is the correct choice as something that is not a component of the Glasgow Coma Scale.