What would YOU do?

My sister has had an undiagnosed condition for three years now... twitching in her legs daily, muscle pain like you just ran 1000 miles, and leg fatigue. She has seen neurologists, physical therapy, rhematoid doctors and her PCP. Multiple MRIs and blood work. All negative. She's had some genetic testing...that was negative. She has wanted to end her life because the symptoms are there EVERY day, all day. She tried to do a study, but was rejected as they could only accept so many participants. She's at a dead end, what would you do? She does have another appointment with a sixth neurologist, but that may lead to no answer as well. Any ideas?