From the Guidelines
Decorticate and decerebrate posturing involve different brain locations, with decorticate posturing resulting from damage to the cerebral cortex or its connections above the red nucleus in the midbrain, and decerebrate posturing indicating more severe brain damage involving the brainstem at the midbrain-pontine level. Decorticate posturing causes flexion of the arms, wrists, and fingers with extension of the legs, due to the disruption of the corticospinal tracts above the red nucleus in the midbrain 1. On the other hand, decerebrate posturing produces extension and pronation of the arms with extension of the legs, as a result of the damage to the structures between the red nucleus and vestibular nuclei, particularly the brainstem at the midbrain-pontine level.
The brainstem, which connects the midbrain to the medulla, plays a crucial role in the development of decerebrate posturing, as it contains important white matter tracts and cranial nerve nuclei 1. The pons, a part of the brainstem, is frequently affected by ischemic and hemorrhagic infarcts, which can lead to acute brainstem syndromes and decerebrate posturing. The difference in posturing patterns reflects the progressive loss of inhibitory influences as damage extends downward through the brain.
Key characteristics of decorticate and decerebrate posturing include:
- Decorticate posturing: flexion of the arms, wrists, and fingers with extension of the legs
- Decerebrate posturing: extension and pronation of the arms with extension of the legs
- Brain locations involved: cerebral cortex or its connections above the red nucleus in the midbrain (decorticate), and brainstem at the midbrain-pontine level (decerebrate)
- Prognosis: decerebrate posturing generally indicates a worse prognosis than decorticate posturing, as it suggests deeper brain involvement. When observing either posture in a patient, immediate medical attention is required as they indicate serious neurological compromise.
From the Research
Brain Locations for Decorticate and Decerebrate Posturing
- Decorticate posturing is associated with damage to the cerebral cortex, while decerebrate posturing is associated with damage to the brainstem, specifically the midbrain and pons 2
- Decorticate posturing involves flexion of the upper extremities and extension of the lower extremities, and is typically seen in patients with cerebral cortex damage but intact brainstem function
- Decerebrate posturing, on the other hand, involves extension and pronation of the upper extremities, and is typically seen in patients with brainstem damage, particularly in the midbrain and pons
- The study highlights the importance of distinguishing between decerebrate-like posturing and true decerebrate posturing, as the former can be a spinal cord reflex that occurs after brain death 2
- In the case report presented, the patient exhibited decerebrate-like posturing 36 hours after brain death declaration, which was attributed to spinal cord reflexes rather than retained brain stem function 2