Hello Mr. Varghese,
Antiphospholipid antibody syndrome (APLA) is a well know disease that is associated with systemic lupus erythematosus (SLE) but can occur on its own as well. The syndrome increases the possibility of clotting, which may have been responsible for the development of your wife's hemichorea.
Unfortunately, there is no known cure for APLA or SLE. To my knowledge, stem cell therapies have not been shown helpful in these diseases. The main treatment issues revolve around preventing clots and suppressing the antibody formation. Your wife may want to see a rheumatologist if she has not already. (Rheumatologists are specialists in autoimmune diseases.)
New breakthrough's in medicine are being made all the time. Hopefully soon there will be a permanent cure for these diseases.
Advice and opinions given are based on the information provided and must not be considered an official medical recommendation. The limitations of the internet prevent an appropriate evaluation. Always consult your doctor if there is concern.