headaches brought on by mild touch to head

I wanted to know if anyone has experience with this. My 18 year old daughter who has had migraines most of her life can have a migraine brought on by a very light tap to her head. I do mean a very light tap - not even a thump. She winds up in severe pain, tears streaming down her cheeks for hours. She is on amitryptiline everyday for migraine control and it works well except when she receives any mild touch to her head.

Thank you for your reply. The pain is immediate and severe and all over her head when she receives even the slightest bump to her head. The pain usually lasts several hours. The tears are a response of the headache, but often are a result of the amount of pain she is in. Most often she will take Excedrin which does help after an hour or so. She also will usually go to sleep to help the pain go away. While on the amytriptiline, she does not have migraines daily like she used to do. Her normal migraines  come on suddenly and usually begin with pain behind her eyes and are typically accompanied by nausea and occassionally vomiting.  Her face is not affected by the headaches other than her eyes become dark underneath and red. She had a cat scan a number of years ago, but it came back normal.

Thanks. I was already planning to take her.