Attacks or a constant feeling

I have not been ruled out for those. I had an MRI of the brain which was normal. Would they have noticed something of this sort? Also, with respect to Thoracic Outlet Syndrome, I donā€™t seem to have any of the other symptoms this disorder presents.

I will check out the subclavian fistula in the brain.

No, MRI wonā€™t. Please see the articles that is on my Facebook page link to understand the new knowledge on Thoracic Outlet syndrome ( cervical outlet syndrome )

Please keep a diary to what you did before the symptoms started. That will give you a clue. For me , it was my sitting (slouched) , lying on left and my arm movementā€™s. I also weaken my left radial pulse when I go through the symptoms.