Can nerve damage affect smell?

Kate Lamble - Peter just called in. He wants to know to what extent nerve damage affects your sense of smell. He banged his head once which he says resulted in a temporary loss of smell and a permanent aversion to the smell of vinegar. What's going on there?

Darren Logan - So, the effect of damage to your brain after a head injury often lose the sense of smell and that can be for two reasons. Firstly, you can actually have a shearing of the olfactory neurons which can be quite nasty and can often lead to permanent loss. Secondly, you can have, essentially, bruising of the front of your brain when it hits the front of your skull because your brain is soft and your skull is hard. So, you've got a very jarring motion, you can get bruising and that can either be permanent or temporary smell loss. Why he lost it to vinegar? I have no idea.