Three types of<unk>  are decorticate<unk> , with the arms flexed over the chest; decerebrate<unk> , with the arms extended at the sides; and opisthotonus, in which the head and back are arched backward. Decorticate Decorticate<unk> , with elbows, wrists and fingers flexed, and legs extended and rotated inward Decorticate<unk>  is also called decorticate response, decorticate rigidity, flexor<unk> , or, colloquially, "mummy baby". Patients with decorticate<unk>  present with the arms flexed, or bent inward on the chest, the hands are clenched into fists, and the legs extended and feet turned inward. A person displaying decorticate<unk>  in response to pain gets a score of three in the motor section of the Glasgow Coma Scale, caused by the flexion of muscles due to the neuro-muscular response to the trauma. There are two parts to decorticate<unk> . * The first is the disinhibition of the red nucleus with facilitation of the rubrospinal tract. The rubrospinal tract facilitates motor neurons in the cervical spinal cord supplying the flexor muscles of the upper extremities. The rubrospinal tract and medullary reticulospinal tract biased flexion outweighs the medial and lateral vestibulospinal and pontine reticulospinal tract biased extension in the upper extremities. * The second component of decorticate<unk>  is the disruption of the lateral corticospinal tract which facilitates motor neurons in the lower spinal cord supplying flexor muscles of the lower extremities. Since the corticospinal tract is interrupted, the pontine reticulospinal and the medial and lateral vestibulospinal biased extension tracts greatly overwhelm the medullary reticulospinal biased flexion tract. The effects on these two tracts (corticospinal and rubrospinal) by lesions above the red nucleus is what leads to the characteristic flexion<unk>  of the upper extremities and extensor<unk>  of the lower extremities. Decorticate<unk>  indicates that there may be damage to areas including the cerebral hemispheres, the internal capsule, and the thalamus. It may also indicate damage to the midbrain. While decorticate<unk>  is still an ominous sign of severe brain damage, decerebrate<unk>  is usually indicative of more severe damage at the rubrospinal tract, and hence, the red nucleus is also involved, indicating a lesion lower in the brainstem. Decerebrate Decerebrate rigidity or<unk>  extensor<unk> . Decerebrate<unk>  is also called decerebrate response, decerebrate rigidity, or extensor<unk> . It describes the involuntary extension of the upper extremities in response to external stimuli. In decerebrate<unk> , the head is arched back, the arms are extended by the sides, and the legs are extended. A hallmark of decerebrate<unk>  is extended elbows. The arms and legs are extended and rotated internally. The patient is rigid, with the teeth clenched. The signs can be on just one side of the body or on both sides, and it may be just in the arms and may be intermittent. A person displaying decerebrate<unk>  in response to pain gets a score of two in the motor section of the Glasgow Coma Scale (for adults) and the Pediatric Glasgow Coma Scale (for infants), due to the muscles extending because of the neuro-muscular response to the trauma. Decerebrate<unk>  indicates brain stem damage, specifically damage below the level of the red nucleus (e.g. mid-collicular lesion). It is exhibited by people with lesions or compression in the midbrain and lesions in the cerebellum. Decerebrate<unk>  is commonly seen in pontine strokes. A patient with decorticate<unk>  may begin to show decerebrate<unk> , or may go from one form of<unk>  to the other. Progression from decorticate<unk>  to decerebrate<unk>  is often indicative of uncal (transtentorial) or tonsilar brain herniation. Activation of gamma motor neurons is thought to be important in decerebrate rigidity due to studies in animals showing that dorsal root transection eliminates decerebrate rigidity symptoms. Transection releases the centres below the site from higher inhibitory controls. In competitive contact sports,<unk>  (typically of the forearms) can occur with an impact to the head and is termed the fencing response. In this case, the temporary<unk>  display indicates transient disruption of brain neurochemicals, which wanes within seconds.
Abnormal posturing
Copropraxia
Dyskinesia
Metamorphopsia
Hemimotor neglect
Hyperreflexia
Diplophonia
Spasticity