as Thomas says, it could be Hypnic/Myclonic jerks (
https://en.wikipedia.org/wiki/Hypnic_jerk /
https://en.wikipedia.org/wiki/Myoclonus), which I have suffered from in the past.
I currently have Benign Fasciculation Syndrome (
https://en.wikipedia.org/wiki/Benign...ation_syndrome) which my GP tells me is probably brought on by stress/anxiety.
the problem is that twitching like this is a symptom of lots of things & it's not possible to diagnose anything from the twitches alone. you may find it passes after a few days of not drinking - withdrawal always worsened my symptoms - but if not I would recommend going to see your GP about it & being honest with them