Recovering from Mild TBI
Mary Ann Keatley, PhD, CCC and Laura L. Whittemore, Brain Injury Hope Foundation
Chapter 3 - The Important Role of Brain Filters

Down the bottom there's a small section called "Changes in energy reserve after injury".

So basically they're saying you need brain rest and at the moment if you're not sleeping well or overdoing it during the day (even though you may think you're taking it easier) you're not getting it and you are left with this foggy brain feeling.

I have to say though, the days my vertigo is worse are the days when I feel foggy brained and blah... sort of a heavy feeling.

I remembered this link about Vestibular Migraine and I'm a person who gets Migraine with Aura from time to time in my life and often wondered if my residual vertigo is actually a vestibular migraine. http://vestibular.org/migraine-associated-vertigo-mav

The days when my vertigo is worse as I described above and feel gross as described are very like I feel when recovering from a migraine. heavy and flat Often takes some days for that feeling to go.

Remembering of course that one doesn't necessarily need the headache component of a migraine for it to actually BE a migraine.