Dragonfly,

If I understand your posts correctly your father was diagnosed by a neurologist with PD nearly four years ago. He was, and still is, prescribed "a vitamin regimen".

At this stage post-diagnosis, a person of his age and symptoms would typically be prescribed several hundred mg per day of levodopa based drugs. Although they do not cure the disease, they dramatically reduce the symptoms for many people for several years.

Try to find out why this approach has not been tried.

Try to get him to exercise, preferably in a social situation. This is likely to reduce the chances of depression developing, which often intensifies the symptoms.

John