Cognitive impairment

Ten years ago, my father was targeting by several teenagers, they were spying at my dad in the early morning for weeks. They noticed that my father was single and weaponless but obviously carrying money on his money belt.  At the early morning, there was silent and nobody on the street. They hit my father badly with bat and when he was sending newspapers on his way to his clients. Unfortunately, he has been robbed at least five times during his work but nobody has been caught. Once a time, he has been sent to hospital and in a coma for several days.

According to the CT scan profile provided by psychiatric doctor, my father’s brain has the scar which has been recovered after the several hurts made by those robbers. I found that he was easily distracted by unimportant things and got stuck on an idea rather than responding to our conversations for these several years. He had the trouble of understanding our speech but rambling or nonsense speech.
He became severe after reversal his night-day sleep-wake cycles, started changing mood shifts, easily to be irritated or anger.