Anyone who was misdiagnosed as Parkinson's and later diagnosed as MSA?

Hi

My dad was diagnosed as Parkinson's 3 years ago when he was 69 years old.

I am questioning if he might have MSA and not Parkinson's. The Parkinson's medicine never seemed to be too effective on his condition. He also lost a lot of weight since the beginning .

Does anyone have similar experience of being misdiagnosed as Parkinson's instead of MSA? How did you figure it out ? I am unsure how to approach this.

Thank you in advance. My best wishes for anyone who is suffering from this disease. And also for the caregivers.