Decorticate posture
Decorticate posture: Excerpt from Handbook of Signs & Symptoms (Third Edition)
Decorticate rigidity, abnormal flexor response
A sign of corticospinal damage, decorticate posture is characterized by adduction of the arms and flexion of the elbows, with wrists and fingers flexed on the chest. The legs are extended and internally rotated, with plantar flexion of the feet. This posture may occur unilaterally or bilaterally. It usually results from stroke or head injury. It may be elicited by noxious stimuli or may occur spontaneously. The intensity of the required stimulus, the duration of the posture, and the frequency of spontaneous episodes vary with the severity and location of cerebral injury.
Although a serious sign, decorticate posture carries a more favorable prognosis than decerebrate posture. However, if the causative disorder extends lower in the brain stem, decorticate posture may progress to decerebrate posture. (SeeComparing decerebrate and decorticate postures,page 185.)
Emergency interventions
Obtain the patient's vital signs and evaluate his level of consciousness (LOC). If his consciousness is impaired, insert an oropharyngeal airway, and take measures to prevent aspiration (unless spinal cord injury is suspected). Evaluate the patient's respiratory rate, rhythm, and depth. Prepare to assist respirations with a handheld resuscitation bag or with intubation and mechanical ventilation, if necessary. Institute seizure precautions.
History and physical examination
Test the patient's motor and sensory functions. Evaluate pupil size, equality, and response to light. Then test cranial nerve function and deep tendon reflexes. Ask about headache, dizziness, nausea, changes in vision, and numbness or tingling. When did the patient first notice these symptoms? Is his family aware of behavioral changes? Also, ask about a history of cerebrovascular disease, cancer, meningitis, encephalitis, upper respiratory tract infection, bleeding or clotting disorders, or recent trauma.
Medical causes
Brain abscess
Decorticate posture may occur with brain abscess. Accompanying findings vary depending on the size and location of the abscess, but may include aphasia, hemiparesis, a headache, dizziness, seizures, nausea, and vomiting. The patient may also experience behavioral changes, altered vital signs, and a decreased LOC.
Brain tumor
A brain tumor may produce decorticate posture that's usually bilateral — the result of increased intracranial pressure (ICP) associated with tumor growth. Related signs and symptoms include a headache, behavioral changes, memory loss, diplopia, blurred vision or vision loss, seizures, ataxia, dizziness, apraxia, aphasia, paresis, sensory loss, paresthesia, vomiting, papilledema, and signs of hormonal imbalance.
Head injury
Decorticate posture may be among the variable features of a head injury, depending on the site and severity of the injury. Associated signs and symptoms include a headache, nausea and vomiting, dizziness, irritability, a decreased LOC, aphasia, hemiparesis, unilateral numbness, seizures, and pupillary dilation.
Stroke.
Typically, a stroke involving the cerebral cortex produces unilateral decorticate posture, also called spastic hemiplegia. Other signs and symptoms include hemiplegia (contralateral to the lesion), dysarthria, dysphagia, unilateral sensory loss, apraxia, agnosia, aphasia, memory loss, a decreased LOC, urine retention, urinary incontinence, and constipation. Ocular effects include homonymous hemianopsia, diplopia, and blurred vision.
Special considerations
Assess the patient frequently to detect subtle signs of neurologic deterioration. Also, monitor his neurologic status and vital signs every 30 minutes to 2 hours. Be alert for signs of increased ICP, including bradycardia, an increasing systolic blood pressure, and a widening pulse pressure.
Pediatric pointers
Decorticate posture is an unreliable sign before age 2 because of nervous system immaturity. In children, this posture usually results from head injury. It also occurs with Reye's syndrome.
Book Source Details
- Book Title: Handbook of Signs & Symptoms (Third Edition)
- Author(s): Springhouse
- Year of Publication: 2006
- Copyright Details: Handbook of Signs & Symptoms (Third Edition), Copyright © 2006 Lippincott Williams & Wilkins.
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Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
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