You can claim the medical expense only if your mother is your dependent.
Unlike most dependents, your parents do not need to live in your home in order to be your dependent, but there are other requirements, such as Support and Income.
Here are some links that might help you determine if you should claim your mother as your dependent.
Steps
to claiming an elderly parent as a dependent
Can
you claim a parent as a dependent?
IRS
Pub 17
