Jan and Steve are right - I didn't even want to think about work that early after surgery either. My surgery was in March and I went back to work start of August. I probably would have had to go back earlier but I had my surgery in Australia and I work in the UK, so had to hang around in Aus for follow up appointments etc. I'm really glad I had so much time off to recover though - when I did go back, I had a staged return ie: 5 hours a day first week, 6 hours second week and full hours the third week. The first week I was really knackered, even almost fell asleep at my desk! Having said that, I went to Australia for a 7 week holiday last November, and ended up staying for the surgery in March, so I think anyone would be tired after having 8 or 9 months off, let alone someone who had had brain surgery. But the body adapts and although I'm probably not back to full speed (before I left I was doing 7 day weeks without a day off for months...I don't plan on repeating this!!) I'm back to doing the odd 10 hour day of overtime on a Saturday, so after a while Ken will probably be able to do pretty well. I did a lot of air travel in Australia back and from hospital, and found the 23 hour flight back here fine, so I'm sure the travel shouldn't be a prob for Ken either. Just as long as he knows he will be more tired to start with and that every day gets better and that (if he has any balance and SSD issues) subconsciously a lot of energy and effort goes into walking straight and having conversations with people and that is quite tiring too. Sometimes at lunch now if I'm having a full on day, I'll just sit at my desk as I find it really stressful to be up in the lunch room as it's so incredibly noisy and I have to ask people to repeat themselves a lot. It's just not, for me, a very enjoyable break to be sitting in that environment. So yeah, as long as he knows he's not superman and he's not going to be back to full speed as soon as he goes back, but each day will be better.
Best wishes
JB