Thank you for you query.
These Gliotic lesions spoken of are scar tissue in the brain, most commonly caused by exclusion(blockage of )a small blood vessel. Those small areas of blood loss then cause the brain tissue to die causing these spots on MRI
. This might have no symptoms at all or severe symptoms , depending on which area of the brain they occur. I trust this answers your question, please feel free to ask if you require any further information.