It is very hard to pinpoint all of these episodes to the VP shunt. These manifestations may be attributed to the primary problem that he had before the shunt was placed in the first place (stroke? pseudotumor? infection?) I believe that there is also some form of mild depression that should be addressed by counseling and some anti-depressant medications. The forgetfulness may also be related to the primary problem. People who had previous strokes have what they call 'vascular dementia' which may be very hard to treat or reverse. I suggest that you inform his neurologist about these episodes and keep close contact with him.
Regards and God bless.
I am 37 and have just had a shunt replaced does stress or anxiety affect vp shunt performance.