images in clinical medicine

T h e n e w e ngl a nd j o u r na l o f m e dic i n e

n engl j med 363;16 nejm.org october 14, 2010 e25

A 72-year-old man presented with a sudden onset of slurred speech. His medical history was unremarkable, and he was taking no med-ications and did not smoke. The physical examination revealed left-sided

facial paralysis and dysarthrophonia. Diffusion-weighted magnetic resonance imag-ing showed a hyperintensity in the right precentral gyrus, reflecting acute cerebral ischemia (Panel A, arrow). Three days after the stroke, the patient showed impaired voluntary innervation. When he was asked to smile on command, he was unable to fully smile because of facial paralysis on the left side (Panel B). However, during emotional encounters, the patient was able to overcome the facial paralysis (Panel C). It is hypothesized that this dissociation of emotional and volitional facial move-ment is due to separate origins of corticofacial projections. The nerve tracts affect-ing voluntary facial movement probably originate from the main motor cortex. Those affecting involuntary movement during emotion probably arise from the caudal cingulate motor cortex, a medial brain region with inputs from the limbic system (see figure in the Supplementary Appendix).Copyright © 2010 Massachusetts Medical Society.

Dissociation of Voluntary and Emotional Innervation after Stroke

Ludwig Kappos, M.D.Matthias Mehling, M.D.

University Hospital BaselBasel, Switzerlandlkappos@uhbs.ch

A B C

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