I'm 3 months post concussion and have been using amitriptyline for 2 months at 10mg to help with sleep. It has helped greatly with my sleep in combination with melatonin, otherwise I wasn't able to fall asleep until 2 - 3 am. I haven't experienced migraines with my concussion thus far, so I can't comment on that. I experience mild to moderate headaches when overstimulated, but not everyday. Just a thought, but it may be worth looking into the differences between Nortriptyline and Amitriptyline structurally, as they are probably very similar compounds and you could be allergic to both- a pharmacists would know. Hope this is helpful!