ABSTRACT
The facial muscles are supplied by the VIIth cranial nerve, which arises from the facial
nucleus in the pons (Fig. 7.1). The facial nerve is accompanied, for part of its course, by
the chorda tympani, which innervates the taste receptors of the anterior two-thirds of
the tongue. The muscles of the forehead are represented in the ipsilateral, as well as the
contralateral, cerebral hemisphere (Fig. 7.2). Stroke is the most common cause of an
upper motor neurone facial palsy, and Bell’s1 palsy the most common cause of a lower
motor neurone palsy. Other causes of facial palsy are rare. The site of the lesion causing
facial palsy is assessed by noting: (1) the pattern of facial weakness and (2) the presence
of other signs.
