Is there a connection between brain surgery for epilepsy and bad behavior in children?

Yes: Certain conditions can predispose children to epilepsy while also causing behavior disturbances. An example of this is hypothalamic hamartomas in which children exhibit laughing seizures while also having behavior disturbances. After brain surgery, children can behave "badly" but this is more a response to being ill than caused by surgery.

Cause or effect?: Brain surgery is done only for very severe disorders of the brain. The surgery is designed to remove a cause for one problem, but other problems may remain. Many children have bad behavior due to brain dysfunction that also causes epilepsy. Some epilepsy medications cause bad behavior. Being treated as a defective child may result in bad behavior. Surgery is rarely the cause.