Not shooting brake related, but I’d bet the VA is barking up the wrong tree. Have you looked into other root causes for migraines, some that most scripts won’t fix. I have had your issue for well over 10 years, went through tons of meds. Narcotics worked cause they relaxed muscles, but I’d be willing to bet your migraines are cervical spine/nerve related.
The docs have just about come to that conclusion for me. My C1-C4 is full of bone spurs, stenosis, and partially collapsed/bulging discs. Twenty dollars says you have lots of tingling that runs down the elbow side of your arm to your outside fingertips as well. Most of it positional or made worse by high intensity activity or prolonged standing?