When applying painful stimuli to an unconscious patient, movement is internal rotation, adduction, and flexion of the arms. This posturing is termed:

• A. Decorticate posturing
• B. Decerebrate posturing
• C. Localization of pain
• D. Flexion withdrawal

Answer: (A)

Abnormal posturing in response to painful stimuli reflects the level of brain injury and reflects disruption of motor pathways. When the arms show flexion with internal rotation and adduction, this pattern is decorticate posturing. It results from injury above the red nucleus in the midbrain that disrupts corticospinal and corticobulbar control, leading to unopposed flexor activity in the upper extremities while the legs may extend. This posture indicates a significant brain injury but is not as dire as decerebrate posturing, which involves extension of the arms and legs and points to a brainstem lesion with a poorer prognosis.

Localization of pain is a conscious, purposeful response where the patient indicates where the stimulus hurts, which isn’t possible in an unconscious patient. Flexion withdrawal is a brief, protective reflex to remove the limb from a painful stimulus and does not produce the sustained, triangular posture pattern seen with decorticate posturing.