My Dad is 58 years old and a couple of years ago he suffered an episode of memory loss. He was at work and all of a sudden couldn't remember his name, his wife's name, family, etc. He went outside and sat in his car - he did this automatically - and for an hour could not even remember where he lived. Nothing.

His memory returned after around an hour and he went to his doctor where they ran tests - the usual, heart, etc. They did not think it necessary to perform any brain scans. They did not mention stroke or TIA, and gave no explanation for his episode.

Since then his personality seems different - he is more aggressive, doesn't seem to care as much, and seems to have less motivation and energy. He has always had a temper and aggressive streak but now it is so much worse, and he takes it out on my mother (he is not physically violent).

He also has a problem in making inappropriate noises for no particular reason; for example when sat at his computer he just shouts out or makes silly noises, sings silly rhymes, etc. He was always very 'immature' in this way (I take after him in some respects!) but this is just plain weird. He says he makes these noises 'in his head' at work.

Do you think we should persuade him to visit his doctor about this? the problem is that he doesnt think he is any different, he can't see the changes.

Not sure if this is normal or some kind of depression perhaps? I guess I just thought you guys may have heard of this before, or have some suggestions for me.

Thanks in advance.