How I explained it all to my young children.
I have 2 young children Nick my 3 year old boy and Sammi my 6 year old daughter. Although they were not aware what was really going on, they were aware that Daddy wasn't well and couldn't play the usual rough and tumble games with them before I had the Op.
We decided that because my surgery fell on Easter week, that from a practical point of view, they would be better off staying with their Nanna in Cumbria whilst I had the surgery. This suited us down to the ground as they couldn't visit me anyway (A Neurosurgical ward is not the place for small children for many reasons) and my wife would have the added complication of balancing visiting times with who could look after them at the time. It simply was not fair on them to bounce them around all over the place at meal times and bed time. Anyway, I was scheduled to be in for between 7 to 10 days, so we planned for the worst.
They were non the wiser, and my wife had a little more freedom.
I ended up coming out after 7 days post op, so it was just in time for them to come back, and it meant that I was not going to miss my son's Birthday, which I was more concerned about. So I was looking forward to the early release. Well, the best laid plans of mice and men are never straight forward, and it was decided that the kids would not come home until the day after I got home. My wife was at work, and I couldn't manage to look after them on my own on my first day out. So I did miss my lad's birthday after all.
When they arrived home, I was so glad to see them, and it was all I could do not to give them a big hug and a squeeze. They usually gave me one back you see, and at that point, as tender as I was feeling, I didn't think that it would be a great idea. I had kept the dressing on whilst I explained it to them.
I did not really think that they would understand that Daddy has just had a Foramen Magnum Decompression procedure to alleviate the symptoms of Arnold Chiari Malformation and Syringomyelia and that they had to cut away part of my skull to ensure the proper flow of Cerebrospinal fluid. The same fluid that had been trapped inside my skull (and spine) as there was nowhere for it to go because the Cerebellar Tonsils that belong to my brain had herniated beyond the base of my skull and blocked the usual hole. Hard enough to spell correctly without spell check, never mind explain it to young children whilst keeping their interest.
Instead, I told them that daddy had fallen off his bike, and that he had been to hospital to get it fixed. I had a big sore on the back of my neck, and they weren't to touch it or play rough with me for the time being. Well, kids being kids, they wanted to see it. Nervously I peeled back the very clean and well healed wound - they were not fazed one bit! In fact they wanted to stroke it and kiss it to make it better. I have never been so proud of my 2 kids than I was at that moment.
They both gave me a gentle hug and ran off to play with the toys that they had missed whilst they were away.
To this day, they still ask me if my neck is ok, and tell me to be more careful on my bike! They also do generally remember not to be too rough. Although my son did forget on two occasions and he was worried that he had hurt his daddy by hugging him too tightly. (yes, it is that tender initially that the arm of a 3 year old can knock you down)
Aren't kids brilliant? They are innocent, practical, understanding, loving, forgiving and take everything at face value. We don't really give them enough credit. I never regretted being (fairly) straight with them from the start.
Saying that, all kids will react slightly differently, and often at different times react in a different way to that they did 5 minutes ago. This is just an example of my own experience but one that I will never forget and love them for for the rest of my life.
Of course when they get older I will explain the whole thing to them - if they are at all interested that is.
The thing that I am most scared about, is of we have to re-live the whole thing again but this time with one or both of them involved on a more personal basis. Hereditary risk scares me senseless, but at least we are pre-warned and can act more quickly and have the benefit of total awareness about the condition.
Other links:
Government Online Petition to raise awareness. Please take a few minutes to help by signing this?
Are all Chiari Patients the same?
So what is Chiari Malformation?

Further down the line, I just want to give you all an small update.
My kids have proven to take what we all went through when I had my surgery really well. They, as most kids do, have taken it well, on face value and seem to have had no ill effects from it.
They have long forgotten why and how, and now just refer to it as "when I was in hospital getting my neck fixed".
I think kids are great and handle it sometimes far better than us adults do.