continental cast: http://myfishcasting.org/casting_forum/viewtopic.php?p=41263#41263 the finish of it sounds fun !Many people reckon that it's just a version of the Brighton cast. I've also heard of that being called a unitech too so it might well be a version of that. Sleeper cast is a US term as far as I am aware but it's much easier to say and spell than an "aerialized brighton".
Much idea poaching goes on in angling my guess is some one some where tried it, found it was good some one else and others some where noticed and it got named as it spread. Same for a straight Brighton. The 1st cast of that type may have actually been done anywhere.
It's an interesting area. I read and old uk book written long before many people travelled that describes a "continental cast". I've never seen any reference to it anywhere else. Given the nature of some book writers it might be fiction but it does mention light tackle and long rods so who knows. It might even have only been practised in one particular area. It could even have died out.