Hello Dr. My Dad Has Been Suffering From Parkinson Disease

Hello Dr.
My Dad has been suffering from Parkinson disease for the past 4 years. He has taken treatment in local hospital, Tirunelveli district and the treatment is of no effect. As we are living in Chennai, its too far for him to visit there once in every 15 days.
Can you Please recommend any best and experienced Doctor in Chennai for the Parkinson Treatment.

Thanks in Advance