From the Wikipedia page on Brainstorming:
Some governmental organisations (The Welsh Development Agency and the Department of Enterprise, Trade and Investment in Belfast) have reached the conclusion that the term ‘brainstorming’ is offensive to people with epilepsy. Some organisations have suggested the alternative “mind shower”. However, research by the National Society for Epilepsy found of those affected by epilepsy questioned, 93% found the term inoffensive. Some resented the term “mind shower” because of the suggestion that people with epilepsy were, as a group, easily offended.