Not sure how many years of service you have. If you are very close to 20 years, it may be advantageous to continue to serve until at least 20 years of service.
I get you may be trying to be helpful, but the question is not only as to when the condition was incurred. Every member enters the service under the presumption of "sound condition," so, even if it did exist prior to service, the condition is also presumed to have been service aggravated. Absent a notation on entrance medical records, the condition is presumed to have been incurred while entitled to basic pay. Past that, it is also presumed to have been service aggravated. These presumptions can only be overcome by "clear and unmistakable evidence." This is a very high evidentiary standard to overcome.
Lots of "issues" with these questions. First, while it is definitely helpful to have a well-credentialed provider (including a neurologist, be it a military or civilian provider) diagnose or treat you, it is not a requirement to getting an unfit finding or a rating. (Many years ago, there was a whole rigamarole with getting migraines deemed "prostrating" which included a diagnosis and treatment plan that said that you did not need to go to seek medical care each migraine....that is not the case now). An MRI will not diagnose or impact a migraine case. Injury that is causally connected may help with some issues, but is not required at all. Meds are helpful, I guess, as it shows a physician/providers believes you have a severe enough condition, but, this is not required for either an unfit finding or a VA rating.
As for the "in the line of duty" issue, see my previous answer regarding the presumptions and the evidentiary standards required to overcome them.
I don't mean to be purely critical or push back on your efforts to help. My reaction is that you have described many factors (when the migraines were incurred, who diagnosed them, medications, etc.) that, if are present and favorable, would help in making a case. But, none of these factors are strictly needed. I have seen many cases without the factors cited that still resulting in the grant of an unfit finding and a high rating. Each case is different and the facts and circumstances of each case are key in the outcome. I just mean to suggest that a lot of cases are improperly or poorly addressed and it is not a "requirement" that each of the points you raised are needed to be (favorably) present in order to get a rating. I have personally had many cases where none of the factors suggested in your post (time of incurrence, military neurologist providing the diagnosis, medications present) and have gotten a favorable finding. I actually have a current case in Federal Court that is settling with a retirement finding in the absence of the majority of these issues).
I would say that you have identified helpful findings to get a favorable outcome, but, I don't want people to think that the points you raised are neccessary to get a favorable finding.
Additionally, as
@Nala2493 stated, he is a member of the USN....well, the Navy has a habit of finding members fit inappropriately, in my opinion, and experience.
My guess is that your NMA probably was not very strong, or you are relatively senior in grade and have had good evalutions, have had good duty performance, and may have had relatively weak statements from your physicians about impact on your duty performance. Those factors would weigh towards an erroneous fit finding.
Sounds like a good idea/plan.
I don't know why an MRI would be needed or indicated for a migraine diagnosis. An MRI does not factor into a migraine diagnosis.
http://www.webmd.com/migraines-headaches/making-diagnosis-mri#1 . This is just not a factor or exam for migraines.
As for cause, recall, the presumptions I stated above.
You don't need an MRI and one won't help your case.
See all of my above posts.
No, you don't need a cause, you don't need an MRI and the it is not the "honor system." It is the application of the presumptions and the law.
The issue I would guess is that you may have had a weak Non-Medical Assessment, you may have had very good recent performance, or you just had a poorly written NARSUM.
See my above posts. The issues you raised would certainly help. But they are not needed.
All due respect, this is FLAT WRONG. The standard for fitness is your ability to perform the duties of your "grade, rank, rate, or office." It is not whether you can serve in ANY CAPACITY. This is an erroneous standard.
I am not going to write a long response here. I disagre with most of it. The thoughts and input may have been heartfelt and have come from a good place and sentiment. Just most of it is wrong.