After a 17 month PCS journey (which included brain fog, nausea, anxiety, cranial tingling, fatigue, dizziness and disability) I finally felt like I had turned the corner in january 2015. Since then I've felt normal but always have had that little feeling that something was not quite right.

During and ever since the PCS I suddenly needed 9-10 hours of sleep at night rather than my lifetime usual of 7 hours. Even to this day.

A month or two after my early 2015 recovery I developed AFIB with no know cause and still suffer with episodes once or twice a month.
I recently discovered that I have moderate to severe obstructive sleep apnea(OSA) after requesting a sleep study. OSA can cause AFIB.
I'm also finding out that my OSA may be related to TBI injuries.
Medscape: Medscape Access

BTW, I had no idea I had OSA, it was a complete surprise.
I'm posting this as a FYI if you should have sleep issues. It could be related to the TBI. You may want to consider a sleep study if you are suspicious. Untreated it can lead to more problems.
-Jim