EXTREMELY PAINFUL ELECTRIC SHOCK SENSATIONS

WHAT COULD BE CAUSING THE EXTREMELY PAINFUL ELECTRIC SHOCK SENSATIONS MY SISTER IS HAVING IN HER LEGS AND RIGHT ARM. SHE HAS BEEN IN REMISSION FROM CERVICAL CANCER FOR SOMETIME NOW. SHE HAS BEEN DOING WELL. SHE TAKES MORPHINE FOR HER PAIN. HOWEVER, BEFORE SHE STARTED TAKING THE MORPHINE AND NOW IT SEEMS WHEN SHE RUNS OUT OF IT.........SHE STARTS TO BECOME DISORIENTED AND ACTS OUT HOPPING AROUND ON HER FEET, HITTING THINGS, ROCKING IN CHAIRS, SCREAMING HELP AT THE TOP OF HER LUNGS, AND SAYS SHE CAN'T LYE DOWN. THAT WALKING AND STANDING UP MAKES IT BETTER. SHE HAS INSOMNIA ALONG WITH THIS PAIN. SHE DESCRIBES IT AS ELECTRIC SHOCK SENSATIONS DOWN BOTH HER LOGS AND IN HER RIGHT ARM. SHE RECENTLY HAD A WRECK TRYING TO DRIVE TO THE EMERGENCY ROOM BECAUSE OF THIS WHERE THEY MADE HER WAIT FOR HOURS AND DID NOTHING BUT GIVE HER MORPHINE AND AND SHE ENDED UP BACK HOME STILL IN THIS PAIN ALL NIGHT. DOCTORS SAY THEY DON'T KNOW WHAT'S WRONG WITH HER. CAN ANYONE PLEASE HELP ME FIGURE OUT THE PROBLEM SO I CAN HELP HER? SHE IS VERY CLOSE AND DEAR TO ME!