1. This is not caused by a root or nerve injury or other disorder (usually determined by exam)
2. There is no obvious cause of the foot drop particularly if other muscle groups are involved in that leg or both legs
For instance, if your doctors already know the foot drop is caused by MS involving your spinal cord there is no reason to get another MRI.
Revere (Rip) Kinkel MD
Professor of Clinical Neurosciences
Director of the Multiple Sclerosis Program
Clinical Neurosciences Director
University of California San Diego