KittyLady,
Yes, it's possible the vibrations/buzzing in the girlie parts is caused by a spinal cord lesion. However, does it really matter?
I have dealt, off and on, with vibrations from the waist down including the girlie parts for 27 years. It can be annoying to uncomfortable. I don't really think about which area of the Central Nervous System is causing this.
Vibrations/buzzing are sensory symptoms and do no harm. It's just part of the disease