This transcript has been edited for clarity.
Matthew F. Watto, MD: Welcome back to The Curbsiders. We had a great discussion on Parkinson’s Disease for Primary Care with Dr. Albert Hung. Paul, this was something that really made me nervous. I didn’t have a lot of comfort with it. But he taught us a lot of tips about how to recognize Parkinson’s.
I hadn’t been as aware of the premotor symptoms: constipation, hyposmia (loss of sense of smell), and rapid eye movement sleep behavior disorder. If patients have those early on and they aren’t explained by other things (especially the REM sleep behavior disorder), you should really key in because those patients are at risk of developing Parkinson’s years down the line. Those symptoms could present first, which just kind of blew my mind.
What tips do you have about how to recognize Parkinson’s? Do you want to talk about the physical exam?
Paul N. Williams, MD: You know I love the physical exam stuff, so I’m happy to talk about that.
You were deeply upset that cogwheel rigidity was not pathognomonic for Parkinson’s, but you made the point – and our guest agreed – that asymmetry tends to be the key here. And I really appreciated the point about reemergent tremor. This is this idea of a resting tremor. If someone has more parkinsonian features, you might see an intention tremor with essential tremor. If they reach out, it might seem steady at first, but if they hold long enough, then the tremor may kind of reemerge. I thought that was a neat distinction.
And this idea of cogwheel rigidity is a combination of some of the cardinal features of Parkinson’s – it’s a little bit of tremor and a little bit of rigidity too. There’s a baseline increase in tone, and then the tremor is superimposed on top of that. When you’re feeling cogwheeling, that’s actually what you’re feeling on examination. Parkinson’s, with all of its physical exam findings has always fascinated me.
Dr. Watto: He also told us about some red flags.
With classic idiopathic parkinsonism, there’s asymmetric involvement of the tremor. So red flags include a symmetric tremor, which might be something other than idiopathic parkinsonism. He also mentioned that one of the reasons you may want to get imaging (which is not always necessary if someone has a classic presentation), is if you see lower body–predominant symptoms of parkinsonism. These patients have rigidity or slowness of movement in their legs, but their upper bodies are not affected. They don’t have masked facies or the tremor in their hands. You might get an MRI in that case because that could be presentation of vascular dementia or vascular disease in the brain or even normal pressure hydrocephalus, which is a treatable condition. That would be one reason to get imaging.
What if the patient was exposed to a drug like a dopamine antagonist? They will get better in a couple of days, right?