Decorticate posturing indicates damage to which region?

Decorticate posturing indicates damage to which region?

• A. Brainstem below midbrain
• B. Spinal cord
• C. Cerebellum
• D. Cerebral hemispheres above the red nucleus

Answer: (D)

Posturing patterns show where motor pathways are disrupted along the brain. Decorticate posturing occurs when the corticospinal tract is damaged above the red nucleus in the midbrain. This loss of cortical inhibition lets brainstem pathways predominate, producing flexion of the upper limbs (elbows, wrists, shoulders toward the trunk) with extension of the legs. In other words, when injury is above the red nucleus, the cerebral hemispheres are affected, leading to this characteristic posture. If the injury were at or below the red nucleus in the brainstem, decerebrate posturing would be expected instead, with extensions of all four limbs. Therefore, decorticate posturing points to damage to the cerebral hemispheres above the red nucleus.

Posturing patterns show where motor pathways are disrupted along the brain. Decorticate posturing occurs when the corticospinal tract is damaged above the red nucleus in the midbrain. This loss of cortical inhibition lets brainstem pathways predominate, producing flexion of the upper limbs (elbows, wrists, shoulders toward the trunk) with extension of the legs. In other words, when injury is above the red nucleus, the cerebral hemispheres are affected, leading to this characteristic posture. If the injury were at or below the red nucleus in the brainstem, decerebrate posturing would be expected instead, with extensions of all four limbs. Therefore, decorticate posturing points to damage to the cerebral hemispheres above the red nucleus.