emotional liability is common in pls,with outbursts/over exaggeration of crying or laughing.
personally i have more problems with suddenly crying.
i can have mood swings or should i say tantrums,this i know is down to frustration when i am over tired or if i can't do something right(omw i sound like a child
i scream and shout for 10 minutes(my barks worse than my bite
) then i am ok like nothings happened.
my son just leaves me to it and knows i need to get it out of my system.
it is frustrating to say the least when your body is no longer able to do what it should.
i hope this helps you understand your relatives emotional state a bit more.
take good care.