Is it possible for doctors to treat concussions?!

Of course. A&E/ ER departments regularly treat people who present with head injuries.
Many of them will just have a soft tissue swelling, some of them will have extreme presentations of skull fractures or open wounds. A lot will have concussion. Its potentially serious. 3 concussive injuries in a 3 year period is considered life threatening.

If people present to me after a head injury I may send them to the ER within 72 hours even though their neuro signs are apparently normal especially if their behaviour is just slightly unusual (which i might not be concerned about if they didn't have a head injury).

NZ registered Osteopath