I know for me haldol caused a jaw spasm that caused me to bite my tongue frequently. I could not take cogentin because it blurs my vision. I have been off of the haldol since January, except for a brief period in May when I was trying to regain control. It has certainly lessened, but it is not gone. I fear it may be permanent too. At least it is not noticeable. Just painful when I bite my tongue!