A 15-year-old male is brought into the emergency room after being hit by a car while riding his bicycle. The team quickly assesses him for injury and notes on the neurologic exam the client responds to external stimuli by arching back his head, extending and internally rotating the arms and legs, extending the elbows, pronating the wrists, and clenching his teeth. The team suspects injury to

  1. the frontal lobe.
  2. the spinal column.
  3. the midbrain.
  4. the cerebral hemisphere.
Number 3 is correct.
Rationale: Decerebrate posturing includes arching back the head, extending and internally rotating the arms and legs, extending the elbows, pronating the wrists, and clenching the teeth. Decerebrate posturing is indicative of an injury to the midbrain. Frontal lobe injuries usually affect emotions, while cerebral hemisphere injuries can affect problem-solving, memory, and coordination. Injuries to the spinal cord may result in paralysis.