Читать книгу Neurology - Charles H. Clarke - Страница 115

A complete LMN facial palsy affects all facial muscles on one side. Upper motor neurone (UMN) weakness affects the lower face; this spares blinking and forehead wrinkling. In early UMN facial weakness a hint of slowing of a blink, or grimace is all that may be seen, sometimes with dissociation between voluntary and involuntary movement.

Make suggestions:

 Frontalis: ‘look upwards’ produces furrowing of the brow.

 Orbicularis oculi: ‘screw up your eyes tightly’

 Alae nasae: ‘wrinkle your nose’

 Orbicularis oris: ‘now try to whistle gently’

 Risorius: ‘… and now please show me your teeth’

 Platysma: ‘tension the skin of your neck’.

Involuntary movements (e.g. myokymia, fasciculation and slight hemifacial spasm): illuminate the face well. Finally, as a practical point, gradual emergence of patchy facial weakness is distinctly unusual in Bell’s palsy.