Hi Fiona,
I'm a new subscriber to this C-Palsy list. When I read your e-mail, I was so relieved! I thought I was the only person suffering from these problems.
I've had a few counselors who've explained it as related to past family difficulties, but I've never quite agreed with that.
So yes, I too have had problems with odd bursts of laughter. And when I get angry (which is thankfully, not often) watch out!
Thanks for brightening my day!
Vince