It’s all very well to tell a patient with Bell palsy – they haven’t had a stroke and they are likely to recover. When half their face appears paralysed such assurances aren’t all that comforting.

No doubt it might help if we knew a little more about why the palsy occurs in particular individuals, if we had a proven effective treatment for it or even if we could say which individuals were most likely to make a full recovery.

Well now a Korean study looks likely to provide some answers to at least part of this puzzle.