STUDY - Technical - New Dacian's Medicine
Decerebrate
posture (Classical / Allopathic Medicine)
Decerebrate
posture (decerebrate rigidity, abnormal extensor reflex) is
characterized by adduction and extension of the arms, with the
wrists pronated and the fingers flexed. The legs are stiffly
extended, with plantar flexion of the feet. In severe cases,
the back is acutely arched (opisthotonos). (See Recognizing
decerebrate posture.)
This sign
indicates upper brain stem damage, which may result from
primary lesions, such as infarction, hemorrhage, or tumor;
metabolic encephalopathy; head injury; or brain stem
compression associated with increased intracranial pressure
(ICP).
Decerebrate
posture may be elicited by noxious stimuli or may occur
spontaneously. It may be unilateral or bilateral. With
concurrent brain stem and cerebral damage, decerebrate posture
may affect only the arms, with the legs remaining flaccid.
Alternatively, decerebrate posture may affect one side of the
body and decorticate posture the other. The two postures may
also alternate as the patient's neurologic status fluctuates.
Generally, the duration of each posturing episode correlates
with the severity of brain stem damage.
ALERT:
If you observe decerebrate posture:
- ensure a patent airway
- turn the patient's head to the side to prevent aspiration (Don't disrupt spinal alignment if you suspect spinal cord injury.)
- examine spontaneous respirations, and institute emergency measures if necessary.
After the patient has stabilized, perform a focused assessment.
If you observe decerebrate posture:
- ensure a patent airway
- turn the patient's head to the side to prevent aspiration (Don't disrupt spinal alignment if you suspect spinal cord injury.)
- examine spontaneous respirations, and institute emergency measures if necessary.
After the patient has stabilized, perform a focused assessment.
HISTORY:
Explore the history of the patient's coma. If you can't obtain this information, look for clues to the causative disorder, such as hepatomegaly, cyanosis, diabetic skin changes, needle tracks, or obvious trauma.
Ask the patient's family when his level of consciousness (LOC) began deteriorating. Did it occur abruptly? What did the patient complain of before he lost consciousness?
Review the patient's medical history for diabetes, liver disease, cancer, blood clots, or aneurysm.
Ask the patient's family about an accident or trauma that could be responsible for the coma.
Explore the history of the patient's coma. If you can't obtain this information, look for clues to the causative disorder, such as hepatomegaly, cyanosis, diabetic skin changes, needle tracks, or obvious trauma.
Ask the patient's family when his level of consciousness (LOC) began deteriorating. Did it occur abruptly? What did the patient complain of before he lost consciousness?
Review the patient's medical history for diabetes, liver disease, cancer, blood clots, or aneurysm.
Ask the patient's family about an accident or trauma that could be responsible for the coma.
Recognizing
decerebrate posture
Decerebrate posture results from damage to the upper brain stem. In this posture, the arms are adducted and extended, with the wrists pronated and the fingers flexed. The legs are stiffly extended, with plantar flexion of the feet.
PHYSICAL ASSESSMENT:
Take the patient's vital signs, and determine his LOC; use the Glasgow Coma Scale as a reference. Be alert for signs of increased ICP (such as bradycardia, increasing systolic blood pressure, and widening pulse pressure) and neurologic deterioration (such as altered respiratory pattern and abnormal temperature).
Evaluate the pupils for size, equality, and response to light.
Assess deep tendon and cranial nerve reflexes, and test for doll's eye sign.
Decerebrate posture results from damage to the upper brain stem. In this posture, the arms are adducted and extended, with the wrists pronated and the fingers flexed. The legs are stiffly extended, with plantar flexion of the feet.
PHYSICAL ASSESSMENT:
Take the patient's vital signs, and determine his LOC; use the Glasgow Coma Scale as a reference. Be alert for signs of increased ICP (such as bradycardia, increasing systolic blood pressure, and widening pulse pressure) and neurologic deterioration (such as altered respiratory pattern and abnormal temperature).
Evaluate the pupils for size, equality, and response to light.
Assess deep tendon and cranial nerve reflexes, and test for doll's eye sign.
SPECIAL
CONSIDERATIONS:
Relief of high ICP by removal of spinal fluid during a lumbar puncture may precipitate cerebral compression of the brain stem and cause decerebrate posture and coma.
Relief of high ICP by removal of spinal fluid during a lumbar puncture may precipitate cerebral compression of the brain stem and cause decerebrate posture and coma.
PEDIATRIC
POINTERS:
Children younger than age 2 may not display decerebrate posture because of the immaturity of their central nervous system. However, if the posture does occur, it's usually the more severe opisthotonos. In fact, opisthotonos is more common in infants and young children than in adults and is usually a terminal sign.
In children, the most common cause of decerebrate posture is head injury. It also occurs with Reye's syndrome - the result of increased ICP causing brain stem compression.
Children younger than age 2 may not display decerebrate posture because of the immaturity of their central nervous system. However, if the posture does occur, it's usually the more severe opisthotonos. In fact, opisthotonos is more common in infants and young children than in adults and is usually a terminal sign.
In children, the most common cause of decerebrate posture is head injury. It also occurs with Reye's syndrome - the result of increased ICP causing brain stem compression.
PATIENT
COUNSELING:
Inform the patient's family that decerebrate posture is a reflex response, not a voluntary response to pain or a sign of recovery. Offer emotional support.
Inform the patient's family that decerebrate posture is a reflex response, not a voluntary response to pain or a sign of recovery. Offer emotional support.
Bibliography:
1. Rapid Assessment, A
Flowchart Guide to Evaluating Signs & Symptoms, Lippincott
Williams & Wilkins, 2004.
2. Professional Guide to
Signs and symptoms, Edition V, Lippincott
Williams & Wilkins, 2007.
3. Guide to common
symptoms, Edition V, McGraw - Hill, 2002.
Dorin,
Merticaru (2010)