Which posturing is characterized by rigid extension of the arms and legs and indicates severe brainstem injur… - DSSSB 6 September 2024

DSSSB 6 September 2024

Medical & Surgical Nursing

Easy

Appeared in: DSSSB 6 September 2024

Explanation

Decerebrate posturing is characterized by rigid extension of all four extremities.
The arms are extended, adducted, and internally rotated, with the wrists pronated and fingers flexed.
The legs are stiffly extended with plantar flexion of the feet.
This posture indicates severe damage to the brainstem, specifically at or below the level of the red nucleus (e.g., midbrain, pons).
It is generally considered a sign of more severe brain injury than decorticate posturing.

Option A: Decorticate posturing involves flexion of the arms, wrists, and fingers, not extension. The arms are pulled in toward the 'core' of the body.
Option C: Opisthotonus is a more generalized and severe hyperextension of the entire body, causing a characteristic arching of the back. It is not specific to limb posturing from brainstem injury.
Option D: Flaccid paralysis is the complete loss of muscle tone and motor reflexes. This is the opposite of the rigid extension described in the question.

Clinical Relevance

Nursing practice connection: Knowing The concept tested is the identification of abnormal posturing types and their correlation with specific levels of neurological injury helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Recognizing the difference between decorticate and decerebrate posturing is a critical nursing assessment skill. A change from decorticate to decerebrate posturing indicates neurological deterioration and brain herniation, which is a medical emergency requiring immediate intervention.
The Glasgow Coma Scale (GCS) includes motor response as a key component. Decorticate posturing scores a 3, while decerebrate posturing scores a 2, reflecting its greater severity.
What if? If a patient initially presents with decorticate posturing and later develops decerebrate posturing, the nurse must immediately notify the physician. This change signifies that the injury is progressing downward to involve the brainstem, increasing the risk of respiratory and cardiac arrest.

How to Approach the Question

First, analyze the keywords in the question: 'rigid extension of the arms and legs' and 'severe brainstem injury'.
Recall the two main types of abnormal posturing related to severe brain injury: decorticate and decerebrate.
Differentiate between them based on arm position. 'Decorticate' involves flexion (arms to the 'core'). 'Decerebrate' involves extension.
The question specifies 'extension of the arms,' which directly points to decerebrate posturing.
Confirm the location of injury. Decerebrate posturing is associated with brainstem damage, which matches the question.
Eliminate the other options. Opisthotonus is a different type of arching, and flaccid paralysis is the absence of tone.

Concept Tested & Keywords

Concept Tested: The concept tested is the identification of abnormal posturing types and their correlation with specific levels of neurological injury.
Stem keywords: posturing, rigid extension, arms and legs, severe brainstem injury
Lead-in keywords: Which
Negative lead-in flag: false

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E6 Physiology Ganong 27e Vol 1 Part 2 pp. 18-20, 19-21, 30-32