Yes I do have occasional brain fog. When I am tired all of my symptoms get worse. I work hard at resting as much as I can during the day and not scheduling too much. The brain fog can also be symptomatic of Fibromyalgia, but I suppose that you have already been examined for that.

Parkinson's (PD) tends to result in a lot of muscle rigidity, somewhat like a bad muscle cramp only worse (feels like knots in your muscles) PD symptoms also tend to be one-sided. There can also be a clumsy-gait with PD. That was my first indication. When I would walk, especially when tired, I would drift to the right and my right foot would also drag and cause me to stumble. While most people think of tremors as the main symptom of PD I have not had very much of that (for which I'm grateful). My neurologist has told me that 15% of PD patients will not have tremors.

There are a lot of non-motor symptoms with PD including sleep disturbances, constipation, very soft voice and many more. i would encourage you to check out the National Parkinson's Foundation website for these non-motor symptoms and see how many apply to you. Also Michael J. Fox has a good website regarding PD with many blogs.

Mayo Connect also has a discussion group regarding PD. Here is the link, https://connect.mayoclinic.org/group/parkinsons-disease/#/!tab=discussions. I would encourage you to read through the different discussion topics there and see how much you might have in common with what PD patients are discussing.

While this may not be much of a comfort, it has been said that it often takes 15 to 20 years before symptoms of many neurological disorders become obvious enough to have a diagnosis. There are Mayo facilities in Minnesota, Arizona and Florida. If you want a second opinion you might consider Mayo. I certainly wish you well in your search. From my own experience I know how difficult this non-diagnosis time can be.

Have you considered another opinion?