Thank you very much for this article. I just had a sudden near syncope experience last night after going for a whole body massage... and yes... I had my neck area massaged too. After about 5 minutes from the massage, my husband and I were in our car heading home... suddenly I felt like the car was tilting on one side and my field of vision getting narrower and narrower... like i was being absorbed by an internal black hole. I was calling help from my husband who was driving and he was frantically calling my name and wanted to send me to the hospital. Luckily, I recovered after a few seconds but still dizzy and very pale. We decided not to go to the hospital and observe my condition at home. When we arrived, my bp was110/90 ( my usual bp's always about 100-90/60-70). Just had 25 mg of Captopril and I slept. Good thing I still woke up. Thank God I'm still alive. Still dizzy though today but not as much as last night.
You probably fainted because of the massage. Massage of the carotid arteries will produce a vagal reaction and cause someone to faint. This was an old technique of stage hypnotists. Decades ago it was standard practice in an ER to massage the carotids when someone came in with an extremely high heart rate (i.e. a cocaine overdose).
This was discontinued and prohibited in a hospital where I worked when it was found massage of the carotids could dislodge clots that could (and did, because this happened in front of me, causing a debilitating stroke in a 50 year old female) cause strokes.
The general rule is never let the masseuse get near the carotids and never use a hand-held vibrating massage device near the carotids.
It is usual for the fainting to take place a short time after the massage. There is a high liklihood a small bit of debri (an atherochlerotic deposit) was dislodged in the carotids and traveled to the brain.
It's above my pay grade to determine the ultimate effects,. but the liklihood is this will be absorbed and won't cause further difficulty.