I don't know much (anything) about Parkinson's and which brain parts
might be affected. Although there are no Organic problems (damage) or
those would have shown up on an MRI, there might still be chemical or
other problems that could be related to the top syndrome-- kind of like
an erratic electric circuit in a string of e.g. Christmas lights.
Someone here back about November had a spouse who stopped breathing a
number of times during the night, then would cough and start up again.
She was a mess, but he didn't seem to be aware he was doing it, since
he was asleep.
  Regarding my comment above about an 'erratic electric circuit', If
such an imbalance occurs it could trigger some electric firing that
might cause some of your symptoms the Dr. is trying to find? Some of us
have had those types of waves show up right away on EEGs, while *lots
of others here show no measurable waves when they had tests.
  Did they ever suggest where the balance problems might be coming
from? (i.e. an area in the brain? ).  I know nothing about Parkinson's
but wouldn't be surprised to hear that some triggers or symptoms could
produce results that were similar between our 2 conditions.
  Stick around if you have time, as some people only read the group
2-3x a week, so someone might have a website or some ideas to share.
And do let us know if anything new turns up in your own case.  This is
a fluid group and a learning place where someone might happen along
with some ideas.
  Have they prescribed anything recently other than antidepressants?
Several of the Anti-ep drugs are used for other conditions cerebral
too.  (Tegretol is used for my type of seizures, but I had heard that
some people who've had strokes or similar conditions are sometimes
given it as well.   And that or some other AED may also open artery
walls slightly, so for some types of bloodflow reduction, it may help
that type of condition too.
  'Read us' for at least a week or 2, as I said some people don't look
here every day, but might have some ideas for you.   G./