Strange symptom ?

I have been on Cabergoline now for a little over 2 months and have developed
a strange symptom. I get a really good night's sleep, but on waking I often find
my right hand clenched tight with fingernail imprints in the hand. This morning
I woke to find my lips numb because my hand was squeezing my mouth so
hard during sleep.
I suppose I shouldn't complain... but isn't it strange ?