My symptoms are definitely worse when I look down and attempt to use my arm in anyway. The back of my neck goes goes numb around the C5-C6 area. It has become worse to the point of disability. I do however have a EMG that suggests nTOS and now a MR Neurogram that shows subclavian vein compression. My neurosurgeon wants me to have a diagnostic block at C5-C6 level to see if that improves any of these symptoms.
Ive had every injections (and imaging) known to man, PT/OT, chiropractic, etc. This is getting worse. I suggest having your neck checked out and/or seek out a TOS specialist if you already have one, get 2nd opinion.