From my personal experience, alcohol has done far worse things to my brain than trauma itself. But, then again, each concussion is highly individualized.

If your initial concussion was alcohol-related, as mine was, I would highly recommend staying away from the stuff as long as possible. Alcohol consumption brings about a chemical environment in the brain very similar to that effected a few hours after large amounts of trauma, and drinking may trigger a "memory effect," therefore putting into motion the secondary processes associated with concussion.

It's your call; I know that, for me at least, if I crush a bunch of beers there's a good chance I won't experience any *perceptible* permanent effects. But there's also a good chance I will. Even if I don't, I know it's probably not the best in terms of long-term recovery and/or re-acquisition of cerebral "toughness." This last part is conjecture, but the toxicity of alcohol and the similarity of its effects to those of alcohol is very much so documented.