Decorticate and decerebrate posturing

David Goldemund M.D.
Updated on 10/08/2024, published on 11/07/2024

decorticate and decerebrate posturing result from damage to the structures that control motor tone associated with the corticospinal tract
- the brainstem is thus disconnected from inhibitory cortical and subcortical pathways
decorticate posturing – the lesion is rostral to the midbrain (e.g., cortex or internal capsule)
decerebrate posturing – the lesion is at or below the level of the midbrain/caudal diencephalon
patients with posturing are typically comatose and often have a poor prognosis; they are at risk for respiratory failure, cardiac arrhythmias, and cardiovascular collapse
- decorticate posturing has a more favorable prognosis than decerebrate posturing
a progression from a decorticate to a decerebrate posture is associated with progressive destruction/compression of brain structures (→ rostrocaudal deterioration)
both types of posturing require immediate medical evaluation and intervention

decorticate posturing
- arms are flexed at the elbows and held inward and close to the body; the wrists and fingers are clenched and held tightly to the chest
- the legs and feet are usually extended and turned inward; feet are at plantar flexion
decerebrate posturing
- patients exhibit rigidity with arm and leg extension, wrist flexion, and foot plantar flexion
- these signs can be intermittent, unilateral or bilateral and may involve the upper extremities only

mixed decerebrate rigidity (reverse decerebrate syndrome)
- extensor posture in the upper limbs and a flaccid or flexed posture in one or both lower limbs
- results from primary lesions in the pontine tegmentum, particularly affecting the vestibular nuclei and vestibulospinal tracts
- prognosis is fatal (mortality 100%)

Motor response	Lesion location	Mortality
decorticate rigidity	cortico-subcortical level	~ 50%
decerebrate rigidity	caudal diencephalon-upper brainstem	~ 85%
mixed decerebrate rigidity	pons	~ 100%

neurological examination and neuroimaging (CT or MRI) are used to identify the underlying cause (hematoma, contusion, brain edema with herniation, etc.)
- non-contrast computed tomography (NCCT) – baseline imaging in the acute setting
- magnetic resonance imaging (MRI) may better show cerebral edema or tumor progression; however, it is reserved for stable patients

focused on the underlying cause
- surgical intervention
- medical management and supportive care