Hi
Thanks for the question on MedHelp forum!
At times mild traumatic brain injury causes brain damage not very apparent on MRI. MRI would need to be done with and without contrast for these. The frontal lobe is associated with mood and memory. Thus any damage to this lobe can lead to long term memory loss, mood swings, talking too much, and energy bursts leading to over activity. Long term complication is chance of schizophrenia.
There is a possibility that your friend has auditory and visual hallucinations typical of schizophrenia that prompt him to take actions he is taking now. Please get him evaluated in neuropsychiatry or by a psychiatrist.
Hope this helps. Please let me know if there is any thing else and do keep me posted. Take care!
There's a condition called frontal lobe syndrome, where one shows a progressive deterioration in proper social skills and a lack of empathy. They seems to be void of all emotions and they can't understand others emotions. Although, I'm pretty sure this condition is consistent with organic brain damage, seen as lesions on a MRI or CTScan. So, I wouldn't doubt that the manifesting symptoms are extremely noticeable and completely inconsistent with social norms.
Something more likely is post concussion syndrome, where one experiences depression, anxiety, headaches, dizziness, irritability, anger and aggression, with the latter being most common and former being least common.
Issues with school (due to concentration problems or carelessness) and troubling doing daily tasks (psychomotor retardation) may be a warning sign of impending depression, although it's important that he or she have problems in their mood/interest/pleasure, sleep, and appetite to differentiate between PCS and MDD.
A psychiatric disorder manifesting as a personality change, which is commonly reported by loved ones of TBI victims, can't be inferred using traditional medical imaging techniques. But, trust me, it happens, I been there. It is best to get evaluated at a neuropsychiatry and neuropsychology department. In contrast with a neuropsychologist, who evaluates mostly cognitive problems (language, memory, planning, learning, decision-making), a neuropsychiatrist specializes in behavioral disorders after TBI.
I know that sounds like a lot. I'm only assuming the worst. Use your best judgment in deciding whether his actions are purely of free will. Cheating on his girlfriend and not showering could be symptoms of living as a teenage boy in college. Been there too. Good luck with everything.
As I mentioned scans can only show so much. Even people on coma has shown nothing on MRI in several cases. You can go fMRI (functional MRI), SPECT scan. The best bet would be to go for Neuro phycologist.
A family friend who is a doctor first pointed out that it could be brain damage. Scans were done at the hospital on the day of the accident, i don't think they revealed anything.
Any CT scan or MRI done on? Consulted any doctor or neuro phychologist or neurologist? Anything is possible after head injury even if nothing shows on scans. Neuro phychologist will be your best bet.