It is rare when thetraditional New England Journal of Medicine forgets it’s past. Thus you have to conclude that the appearance of two “Images in Clinical Medicine” on our topic of yesterday within 12 years is intentional rather than careless:
- The 2010 article shows a volitional facial paralysis in a small cortical right-sided stroke
- The 1998 articles shows both a volitional and an emotional facial paralysis
What do you think?
Whatever, we explore the classic phenomenon of dissociative facial paralysis which led old textbooks to infer a localizing value of volitional facial paralysis (e.g. has to be capsular or higher). Nowadays we know from case reports that emotional facial paralysis can appear in medullary, AICA, capsular and many more lesion locations, leaving the path of emotional facial innervation completely unclear and thus reducing the localizing value of dissociation.
So in my view, it is still one of the most fascinating physiological (and phylogenetic) facts that nature decided to devote so much energy intoproducing emotional facial expression (also having to come up with quite a lot of machinery to recognize them). But it helps nada in the daily life of a Neurologist.