I'd say the majority of head bumps, concussion or not will recover just fine.

I had a LOC @ age 15 , but don't recall any other problems other than a bit fatigued for a day or 2 after.
I do think it somewhat affected my neck a bit ( went off horse head first onto ground ) so that in my middle age years and with repetitive job, I started having issues w/ neck, shoulders hands etc..
I definitely think my c1 c2 got knocked out of alignment back then also.
Your neck muscles could be affected , do you know about trigger points and referred pain?
You could ask for a few sessions of PT - they should know how to check for spasmed muscles & trigger points..


Perhaps it could be the actual chewing of the gum more than the nicotine??

It might be wise to see a upper cervical chiro just to make sure there is no problems in the future. Especially if you have had other bumps or falls that might have jarred the neck/head.You can see some videos on youtube if you want to know how it is done.