Certified Rehabilitation Registered Nurse (CRRN) Practice Exam

Which cranial nerves are most affected in persons with multiple sclerosis?

1. I and II

2. II and III

3. III and IV

4. IV and V

The correct answer is: II and III

Persons with multiple sclerosis (MS) commonly experience symptoms related to the optic nerves, which are associated with the second cranial nerve, also known as cranial nerve II. This occurs because MS often leads to demyelination within the central nervous system, including the optic pathways, resulting in vision problems such as blurred vision, double vision, or even loss of vision in severe cases. Additionally, cranial nerve III, the oculomotor nerve, can also be affected in individuals with MS. It controls eye movements and pupil response, and its involvement may contribute to further visual disturbances and issues with eye alignment. The involvement of cranial nerves II and III highlights the visual impairments that often accompany MS, making this combination particularly significant in the context of the condition. In contrast, other cranial nerves listed are less commonly impacted in MS or tend to be associated with different symptoms that are not as directly linked to the hallmark manifestations of the disease. Thus, the focus on cranial nerves II and III aligns with the typical clinical presentations seen in patients with multiple sclerosis.