Which component is not part of the Glasgow Coma Scale: eye opening, peripheral reflexes, best motor response, or best verbal response?

Glasgow Coma Scale Components

Peripheral reflexes are not included in the Glasgow Coma Scale. The GCS comprises only three components: eye opening, best motor response, and best verbal response. 1

The Three Components of the Glasgow Coma Scale

The GCS is structured around three distinct assessment categories, each scored independently before being summed for a total score ranging from 3 (deep coma or death) to 15 (fully awake). 1

Eye Opening Response (1-4 points)

• Does not open eyes = 1 point
• Opens eyes in response to painful stimuli = 2 points
• Opens eyes in response to voice = 3 points
• Opens eyes spontaneously = 4 points 1

Best Verbal Response (1-5 points)

• Makes no sounds = 1 point
• Incomprehensible sounds = 2 points
• Utters inappropriate words = 3 points
• Confused, disoriented = 4 points
• Oriented, converses normally = 5 points 1

Best Motor Response (1-6 points)

• Makes no movements = 1 point
• Extension to painful stimuli (decerebrate response) = 2 points
• Abnormal flexion to painful stimuli (decorticate response) = 3 points
• Flexion/withdrawal to painful stimuli = 4 points
• Localizes painful stimuli = 5 points
• Obeys commands = 6 points 1

What the GCS Does NOT Include

Peripheral reflexes are explicitly excluded from the GCS assessment. 1 While brainstem reflexes (pupillary light reflex, corneal reflex, oculovestibular reflex) are critical for neurological prognostication—particularly in post-cardiac arrest patients—they are separate clinical examination findings and not part of the GCS scoring system. 1, 2

Clinical Application Considerations

The motor component has emerged as the most robust predictor of neurological outcome, particularly in intubated patients where verbal assessment is impossible. 1 The GCS must be described according to each of the three components (Eye-Verbal-Motor) rather than just reporting the sum score, as this provides more granular clinical information. 1

Common pitfall: The motor response rating demonstrates the highest interrater variability among nurses and clinicians, with only 35% accuracy in some studies, compared to 89% accuracy for verbal responses. 3 Education in neurosurgical assessment significantly improves GCS scoring accuracy (p=0.004). 3