@jlam1950 I’m not familiar with this speciality so I looked it up. Here is what I found on the Cleveland Clinic website which is a reliable website with valid information. When you get to the bottom of the page you will see that Clinical Neurophysiologist is described.

Cleveland Clinic: What is a Neurophysiologist?

— https://my.clevelandclinic.org/health/articles/24965-neurophysiologist