Suggest Treatment For A Brain Condition

My dad is 49 years old and seems to be off compared to what he used to be. The beginning of last year a brain aneurysm (unruptured) was found and since he has had 2 embolizations of it. After the surgeries he has seemed to be a lot more spacey. Often times he seems to just randomly wander around the house without a specific purpose or he will wander out back after work and eventually lay in the hammock. There are things that he has been doing for 25 years that he just stopped doing such as locking the doors at night or emptying the trash once its full. His driving has been off to. Driving the car, he lets it swerve at times and almost goes off the road multiple times and has almost gotten in a few accidents blaming it on the other person coming into his lane. Even when he is home it's like he's not home. Could this be a result of his surgery or is it something else?