Actually, a much fuller; or a full history as possible of his injury and course of treatments etc. may help us have more light shed on what his situation may be and give us a better idea what he may be dealing with to assist you .........

Could he or both of you give us some more details as to what /when he was injured, how; what testing was then done; what followed after that initial period .........

Has he seen any Neurologists, Neuropsychologists, Physiatrists, Physical Medicine specialists ; or is he under anyone's current care?........

Mark is correct:

- Seizure activity could be responsible for some of those behaviors;
- Alcoholism is intrusive in aiding discovery of problems - as well as being totally toxic to individuals with head injuries;

Kenjhee asks a relevant issue:

- where was his head injury - Frontal, Temporal, Posterior(Occipital) - areas of the injured head/brain leave tell-tale injury in the brain that can result in future problems for long periods, including life-long problems that are in need of continued follow-up with specialists in Neurology/NeuroPsychology.