What does "癫嘎恰嘎" mean?

形容一个人疯疯癫癫、神神叨叨，不是精神病但行为飘忽到令人迷惑，就像灵魂背着人偷偷出门兜风那种态。

ENThey ain’t nuts, but they sure act like it—“dian-ga-qia-ga” is local code for someone who's just weirdly wacky, like brain’s running its own Netflix show.