I also had a Doppler ultrasound of my neck arteries. They were fine but I know that I need to have my neck in a tilted or twisted position for symptoms to show. The tech did not test with odd postures. It takes 10 minutes of bad posture for inflammation to cause me problems.

For me, prolonged bad neck posture causes Central Apnea where my diaphragm stops pulling breaths. I have learned good habits so this is a rare occurrence.

If you have neck pain, it will also cause inflammation. It is the inflammation that causes problems by slowing blood flow and causing other symptoms.