What Can I Do About Double Vision And Vertical Diplopia?

Question: Hi,
My mother (age 52) is experiencing double vision. when consulted with eye doctor, he said her eyes are fine and asked us to consult neurologist. She can see clearly with one eye closed but not with both eyes. She is having Thyronorm 50 mg for thyroid. The neurologist says she experiences vertical diplopia and has prescribed blood test( TSH receptor antibody, ESR, sugar , pressure , Tsh, cbc, creatine, ANA, ACE). earlier 26 years back she had facial palsy of the left eye which was cured through medication and physiotherapy.. Once by accident she had fallen on her left face down and experienced slight bleeding for which we had done MRI scan which was all normal. Later she had experienced redness in the same left eye for which again she was on treatment and now it's better. In the current test report, Her thyroid levels, pressure , ESR, and sugar test are all normal. Even the Tsh receptor antibody test and ACE test is normal. The ANA test shows higher value than normal(31.5). Is this any cause for concern. Will a MRI scan will be required and will the vision of the eyes return to normal after treatment.