Hi Mark,

Called "myoclonic jerks". Can be caused by lots of things but you can have them as a "standalone". My late partner (a doctor) had them, boy do they kick the other person out of bed and I'm not talking twitches, here.

It's most likely to be side-effect of the gabapentin-type drugs - neurontin, topomax, lyrica, some new ones I forget. All epilepsy medication, so might mean you need to ease off.

There's stuff on the net about it, but don't get too worried by what you read - many people develop them anyway, after a certain age, for no good reason and, other than morning stiffness, to no ill effect. Tiring and wearing, though and puts a crimp in your social life if you're single
all the best.