I suffered from tinnitus very badly, it's also an anxiety symptom. Sorry my limited English skills won't tell me what hyperacusis is...
But all the symptoms people experience with migraines, migraine aura, epilepsy can be found in anxiety as well and oh man I had them all. Derialization, blurred vision etc.
Sure people could tell me that was all concussion related but no a slight bump to the head will never do that to you.
I'll quote my neurologist: "I don't know what's wrong with you and why you still have the symptoms. You would have gotten hit my a cannon ball to still experience such symptoms."
That's why so many doctors might give a wrong diagnosis and label you as "brain damaged" and tell you to take it easy, though the main problem might be anxiety.
Anxiety is a wide subject which is unfortunately not clear to all the doctors/therapists out there.
I will give a short summary about anxiety disorders:
Your nervous system is pretty much playing tricks on you. It's not damaged or anything. In most cases people start suffering from anxiety when under a great deal of stress. (Not the most uncommon thing in our society.)
Their nerves get tired/"bad". You react more sensitive to things and might start experiencing symptoms(detachment from the outside world, blurred vision, or just shaky hands etc...)
I think everybody has heard of the flight/fight system before, the nice gift inherited from our acestors.
Well when your nerves are "bad" it kicks in pretty easily and you develop fears. It can be all kinds of fears, fear of health included.
Every slight change in health can be a reason for the person to panic and imagining illnesses.
In my case I heard of concussion a few weeks before I bumped my head. When I bumped it my "bad nerves" convinced me that I had a concussion. I was under a lot of stress before that.
At that my point my body was so tired and run-down that it just shut off and all the symptoms came into place. The diagnosis of the doctors gave me the rest.
There are many ways leading to anxiety and as many people suffer from it.