Suggest Remedy For Loss Of Mobility In Arms Along With Weakness

My daughter-in-law who lives in Florida has experienced for the last two months loss of mobility in upper body especially arms,and also having weakness. when walking short distances she is also experiencing weakness in legs and gets weak and has to rest. She has been to a neurologist, rheumatologist and has extensive blood work done and no doctor has come up any conclusion from the blood work. I have been told that we may want to ask to see if she could have parasites. Do you have any suggestions of what may need to be checked for at this point? Thank you.