Hi - Welcome to our group.
You may not be aware, but we are a group focused on Multiple Sclerosis. Also, we are not doctors, just people with MS or in the process of ruling MS in or out.
MS is a disease that effects nerves. The report mentions 'ischemic' probable cause for the lesion. This refers to blood vessel damage not nerve damage. It sounds unlikely that you Mum has MS. We are not qualified to speak about anything else.
Kyle