As the mother and caregiver of a PCS sufferer,I can only say what I've done (or wish I"d done). I'm no expert.
I keep a "Nathan Notebook" that I should've started a
long time ago! Try to keep notes of dr visits, phone calls, school calls, his bizaare symptoms. I don't do an extraordinary job of this: I have 2 other children at home, own/operate my own business, been sick myself, and just this week took in my friend's 10 y/o while she's in the hospital.
I try to observe more and ask less often how he's feeling BUT he doesn't tell me. We'll be sitting at an appointment and they ask him something and he's like 'yeah, all the time'!!!!
I do assist in his daily vestibular therapies so I can give the PT accurate updates.
I ask him what he wants to do or who he wants to have come over to hang out with him. I usually have to facilitate those meetings, though he's getting better.
I stay out of the way while his school tutor is here. He works way better for her than me.
I spend time with him, mostly next to him while he watched TV shows. This helps reduce his loneliness, anxiety, gives me a chance to observe him, and an ocassional nap lol.
He knows I am advocating for him and is willing to try most things I/dr/you guys on here have suggested.
Hardest part was the other day when he asked me if he's ever going to get better.