The word 'brainstorming' is not offensive to the vast majority of people with epilepsy, according to a survey carried out by the National Society for Epilepsy in 2005.
... 93 per cent of people with epilepsy did not find the term derogatory or offensive in any way and many felt that this sort of political correctness singled out people with epilepsy as being easily offended.
Our view is that it depends upon the context: if the word is being used to describe a meeting where participants are suggesting ideas, then its use is not offensive to people with epilepsy. However, it should not be used to describe a seizure or the electrical activity within the brain during a seizure .
http://www.epilepsy.org.uk/press/facts/brainstorming