After doing quite a bit of research on "Rage" I am fairly certain (95%) that "rage" is in fact a form of epilepsy. Just as in humans an epileptic will suddenly have an attack, then so will dogs. Some humans are able to "predict" an attack and use bio feedback therapy to lessen the effects of the attack. Unfortunately dogs cant and this is why the rage attacks are very sudden and leave the dog quite confused afterwards.
I feel from the brief information provided that your dog may be depressed at losing her litter, after all she has an inate maternal instinct to care for her litter and has invested herself in their development and weening.
If the pups are local it may be beneficial to briefly reunite mum with one or two of them, as well as providing a surragate pup in the form of a soft toy for her to "mother".
