Sounds like Dr thinks it's dystonia. My daughter had an episode of that and the ER gave her Benadryl, and her psychiatrist confirmed that that was absolutely what to give if it ever happened again. For my DD1 I think it was because of accidentally skipped medications - winter break always throws us off. However, she was on Wellbutrin SR 150mg and Paxil 10mg at the time ad psychiatrist said both of those had low incidence of dystonia as side effect, but as partial withdrawal, who knows?
From your description, though, it sounds more like stimming than dystonia. On the bright side, Benadryl is a the "magic bullet", the "go-to-guy" of the OTC world - fixes a whole bunch of stuff with minimal, if any, bad effects.
