Richard A. Lewis, MD explains pseudobulbar affect (PBA) in ALS, including causes, symptoms, and how emotional expression can become out of proportion.
What specific screening question do you use to uncover underreported pseudobulbar affect?
Transcript
PBA is pseudobulbar affect. Pseudobulbar affect is where patients will have somewhat uncontrollable laughter or crying after a minimal trigger.
They may laugh when they want to cry, or experience something that is only a little funny that would normally cause a chuckle, but for them becomes five minutes of laughing out loud. This is usually related to frontal lobe problems, specifically frontotemporal involvement, mostly frontal.
If patients have a significant amount of upper motor neuron problems, particularly if they have bulbar dysfunction with upper motor neurons or brisk jaw jerks, they are more likely to have pseudobulbar affect.
There is a standardized questionnaire that was originally used to allow patients to get Nuedexta that we use in clinical trials and in the clinic to determine what degree someone might have pseudobulbar affect.
We talk to our patients that, given what they are going through, some degree of crying and feeling sad is appropriate. However, pseudobulbar affect has less to do with how someone is feeling and more to do with the expression of emotion being out of proportion to what they are actually feeling.
Nuedexta is an interesting compound. It is basically dextromethorphan, which is a cough medicine that suppresses cough. When you give a small amount of quinidine, which is a heart medicine, it helps drive that dextromethorphan into the brain. It affects the frontal lobes in a way that is very effective.
It is remarkable how effective Nuedexta can be, and I have a relatively low threshold to prescribe it if patients are bothered by pseudobulbar affect.
There is still some evidence that Nuedexta may also have effects on speech and swallowing, particularly related to the upper motor neuron bulbar component. Because of this, some people are prescribing it even for bulbar symptoms, even if the affect is not significantly involved.