Decerebration

Decerebration is a term used in neuroscience and clinical neurology to describe a condition in which the cerebrum is disconnected from the brainstem, either as a result of experimental procedures or as a consequence of severe brain injury. In experimental contexts, decerebration has historically been produced by transection of the brain above the brainstem (often at the mesencephalic level), creating a decerebrate preparation that isolates brainstem function from higher cortical influence. Clinically, the term is associated with a pattern of profound brain injury in which cerebral influences are lost while brainstem centers remain functional.

In humans, decerebration is most often discussed in relation to decerebrate posturing (decerebrate rigidity), a severe motor response characterized by extension of all four limbs, with the body sometimes arched and the arms adducted and pronated. This posture reflects disruption of corticospinal pathways and loss of higher cortical control, with relatively preserved brainstem reflexes. Other findings can include impaired consciousness, abnormal respiratory patterns, and varying levels of brainstem reflex activity depending on the extent and location of injury.

Causes of clinically observed decerebrate posturing include large, traumatic or hypoxic-ischemic brain injuries, acute brainstem strokes, intracerebral hemorrhages, and extensive cerebral edema that compromise higher centers while sparing the brainstem to some degree. Prognosis is generally poor and depends on the underlying cause, the extent of brain injury, and the patient’s overall medical condition. In veterinary medicine, decerebration also refers to an experimental state achieved by transection of neural connections, used to study brainstem function.