There are many things that can cause an increase of PCS symptoms. Sleeping with my head hanging down is one of them for me. I wake up feeling miserable. In me, I believe it has to do with neck inflammation and blood supply.

Quick movements can also cause symptoms. Whether this is a new concussion or just an antagonizing of the past concussion, it would be difficult to tell. Realistically, it is a meaningless question since the issue is the return of symptoms, not the exact cause of the symptoms. The important point might be to notice a trend. If sleeping with your head drooped forward causes symptoms, then it would be good to try to avoid that. If a quick head movement causes symptoms, then it will be good to learn to avoid that, too. I am very intolerant of any quick head movements. I have learned to avoid shaking my head No.

So, try to find the trends that lead to symptoms. This will equip you to better manage your PCS.

My best to you.