I cannot remember if I have already posted this or not, but there is a Parkinson's disease specific form veterans who served in Vietnam should fill out if they are pursuing service connection for PD and probable Agent Orange exposure.
Here is the link: PD Disability Benefits Questionnaire
I usually help the veteran fill the form out and expand on the information either via a letter or in the comments section of the form, as the form itself is not very descriptive. In addition to this I always have the veteran get connected with their local Veteran Service Officer (VSO) to help with the applicaiton process.
Do many of you work with Vietnam veterans who inquire about service connection benefits for their PD?