dearcolleague,
working with children with autisme is not at all easy. I suggest you read as much as possible about it... on google you can find many sites about this topic, there are patient organisations which I find are very well informed. On the following site you will find some information about sensory intergration therapy.
The SPD Network - About The SPD Network
I wish you a lot of empathy and patience with these patients. AND of course a good assessment is mandatory to see if treatment is indicated at all.
kind regards
esther