Hi,
Thank you for posting your query.
MRI brain findings as described, in your mother, are suggestive of decrease in blood supply to certain parts of brain, also referred to as brain stroke.
Her neurological deficits such as 
numbness and weakness are a result of that.
Treatment would consist of blood thinners such as 
aspirin, control of risk factors such as 
high BP and sugars, and 
physiotherapy.
Please get back if you require any additional information.
Best wishes,
Dr Sudhir Kumar MD (Internal Medicine), DM (Neurology)
Senior Consultant Neurologist
Apollo Hospitals, Hyderabad,
My personal URL on this website:  http://bit.ly/Dr-Sudhir-kumar 
My email: drsudhirkumar@yahoo.com