Yes, causing brain damage is violence. No, speech can not cause brain damage.
Unless inaction or speech is directly and unmistakeable the cause of someone’s death, then they cannot be held responsible for that death and trying to do so is just an attempt at manipulation.
So it's not possible to insult or threaten somebody - or in this case a child - during a speech according to you. You need to say this explicitly, because people usually think otherwise. Do I need to send you a random Trump speech to prove it to you, that you just moved the goalpost?
Unless inaction or speech is directly and unmistakeable the cause of someone’s death, then they cannot be held responsible for that death and trying to do so is just an attempt at manipulation.