No, no, it’s not a joke. There really is a health condition known as “Exploding Head Syndrome” and though it may be slightly misnamed, it’s quite real. See Wikipedia for an overview. (I do know there’s also a band named “Exploding Head Syndrome,” but I don’t think I want to hear any of their music.) No kidding, though — Exploding Head Syndrome is real and it’s a bad thing.
But it’s not as bad as “Jumping Frenchmen of Maine Disorder.” Yeah, it’s real too, and no, it’s not some cultish practice or cultural custom. In fact it appears to be genetic, so for the sufferers it’s not like they can wish it away. It’s even listed by the National Organization for Rare Disorders (NORD). Just be glad you don’t have it — it’s much worse than Exploding Head, in fact it can result in exploding somebody else’s head. Beware, and stay away from twitchy-looking French-Canadian lumberjacks.
Don’t say I didn’t warn you.