all lesions are on the myelin which coats the nerve and so (i think i am correct in saying) it is on the cord, as opposed to the spine (I presume by spine, you mean the bony vertebrae).
i had a lesion on my spine (by which i mean the cord) and presumably it has since healed up, because one of the main symptoms was the occasional, ‘electrical buzzing’ sensation called L’Hermittes, which i am no longer entertained by.
it would occur only when i flexed my head forward (ie. chin downwards); the tilt of my head causes the back of my skull to effectively pull the cord in spine upwards. due to the reduced myelin, this movement causes a bit of interference to the messages being transmitted and so my hands / feet / legs would tingle.
not an entirely unpleasant situation, but one which nevertheless provided a constant reminder that not all things were perfect.