You could torture me with diphenhydramine. I have restless leg syndrome, bad, take drugs to sleep every night. Women who have slept with me when I missed a pill made damned sure I had one. One gf almost sent me home when I joked about forgetting it. It would have been the couch for sure. Hell, it even gets into my arms when it's bad.
Imagine twitching from the waist down, paralyzed with fatigue from the waist up, screaming to pass out but your legs are doing the Charleston.