Perhaps first to know, is that we couldn't move any muscle(s) in our body without acetylcholine. So it makes sense that if you disrupt the natural workings of acetylcholine with inhibiting drugs, you'll get some kind of reaction from muscles. In most cases, and in most people, it will relax them. But for others, it causes the opposite effect, which can bring on muscle twitching and excitability.
Do you think Stapedial Myoclonus/Dysacusis can be caused by this? Especially when one seems to have neck/jaw issues?