Sheds,

Yes, relapses are common. Except they are called "Decompensations." They are usually the result of a trigger. In your case, I would suggest that you over-worked trying to get as much done a possible when you were at the top of your game. This is a common behavior until we learn that we cannot over-do it. We can but we pay for it later.

Things that can cause decompensations are:
Too much stimulus, crowds, noise, visual clutter
Poor sleep
Pollution such as alcohol, bad diet, excitotoxins such a MSG, NutraSweet, Sucralose.
Mild bumps to the head.
Shaking like from riding down a rough road
Over-doing it.
Emotional stressors
Fever
Pain
Sneezing and coughing
Excessive physical activity
Excessive mental activity
Altitudes, usually above 8000 feet for extended periods
Apnea, sleep apnea both central and obstructive.
A good sign of sleep apnea is a overwhelming need to sleep early in the day. This is a good sign to get checked or have someone watch and listen to your breathing while you sleep

People with prolonged or chronic PCS and mTBI symptoms need to learn to pace themselves. If we want to over-do it to complete a task or social event, we need to plan on decompensating. I can expect a decompensation to last from 4 to 6 hours to as much a two weeks.

I have a recovery routine for when I have a bad decomp. To start my recovery, I go to my bedroom, leave the lights off, turn on my recovery music, and take a long nap.

We can also learn to avoid decomps by understanding when we are starting to over-do-it. At the first sign of a mental or emotional struggle, memory lapse, confusion, etc, we need to drop what we are doing and retreat to a recovery location. Some of the signs are; difficulty sorting out sounds, reading a line over and over, getting spaced out, startle response, blood pressure spikes, feeling sleepy, feeling weak, trouble focusing our eyes on an object, irritability, and a myriad of other symptoms that we learn to recognize.

Hope this helps. I have lived with PCS since I was 10 years old. It took me years to start to recognize the triggers. By avoiding them, I can be free of decomps for extended periods.

Check out Dr Glen Johnson's TBI Guide at www.TBIGuide.com.