A concussion is a traumatic brain injury or TBI. Usually, it's considered a mTBI, mild traumatic brain injury. But a concussion can cause a moderate or severe brain injury too... I've seen 60 year old death certificates that list the cause of death as only "Concussion".

The term concussion is just a word to describe the theory behind the what kind of brain injury it is. There are many kinds of brain injuries and since some of them can't really be seen unless the brain is examined microscopically postmortem - a diagnosis is typically theoretical. Concussion comes from a latin word that means to "shake violently" or something like that.

Typically, in most recent times, the term concussion is used to diagnose a mTBI where the person doesn't lose consciousness for a long period of time or at all. I've seen some articles that say the only difference between a mild, moderate or severe brain injury is length of LOC (loss of consciousness)... but that's not completely true. Although some people are able to recover well enough to work after sustaining a moderate brain injury and some never do after just one concussion, or mild brain injury.

Also, I think most Doctors think of a concussion's effects as those that don't last too long. Even though we all know that isn't always the case. Maybe a few hours to a a few weeks ... maybe a few months at most. And that's where the term PCS comes in. It's for those of us who have to deal with the effects of one concussion for longer than 3-6 months depending on whose making the diagnosis. Some people have to live with some effects of PCS permanently.

(And I'm not exactly sure whether someone like Mark In Idaho or some other members here who have been permanently effects have been diagnosed with PCS or Multiple Impact Syndrome.)

My boyfriend was confused about this too. Some experts said I had PCS and others would say I had an mTBI. My PCP confirmed that they are the same thing.

There are a lot of theories about what PCS is. I've posted about it in another thread... here... http://neurotalk.psychcentral.com/thread166784.html

Some professionals have been taught that PCS could be caused mainly by psychological issues - but I think research has changed that belief, especially most recently. So your therapist might just be "old school".

I personally think it doesn't really matter because you're getting the therapy you need. So my advice, for what it's worth, is not to worry about stuff like this because you're not really doing your recovery a favor by doing so. But if the information can help ease your anxiety - like it does for me - then by all means: have at it!

I assume you have a good attorney since you mentioned that you were in an auto accident - so your attorney can do all the research (or hopefully already knows about this stuff) and will be able to easily prove that what you're healing from is a brain injury, no matter what it's been called or diagnosed, and that it was caused by the accident you were in.

I hope that helps.