Critical Care Registered Nurse (CCRN) Practice Exam

When assessing cranial nerve V, what should the nurse evaluate first?

1. Response to auditory stimuli

2. Response to light stimuli

3. Light touch sensation on the face

4. Muscle strength in the limbs

The correct answer is: Light touch sensation on the face

When assessing cranial nerve V, also known as the trigeminal nerve, the primary focus is on its sensory and motor functions related to the face. This nerve has three branches that provide sensation to the forehead, cheek, and jaw areas. Evaluating light touch sensation on the face specifically assesses the sensory component of cranial nerve V, making it the most appropriate first assessment. Starting with light touch sensation allows the nurse to gauge the integrity of the sensory pathways and determine if there is any impairment in sensation that could indicate neurological issues. Following this assessment, motor function can be tested by evaluating the strength of the jaw muscles, but the initial assessment typically emphasizes sensory perception. Choosing to assess auditory or light stimuli would be relevant for cranial nerve VIII (vestibulocochlear) or cranial nerve II (optic), respectively, and assessing muscle strength in the limbs does not directly pertain to the function of cranial nerve V, which focuses on the face. Therefore, the evaluation of light touch sensation on the face is foundational in assessing cranial nerve V's functionality.