I recently started stuttering after a car accident. I smacked the left side of my head in the accident. Left side of the brain has the Brocha and Wernkie, both are part of speech. I had prior brain tumor in that area so i You most likely did get a concussion, it just didn't knock you out. See a Neurologist and a speech therapist. Also if your accident claim is open, speak to the adjuster or get a lawyer. Stuttering can be a few weeks or lifetime. Good luck to you.