Management of Facial Palsy
Facial palsy can devastate patients. Facial appearance can be grossly distorted by the sagging of half the face, often accompanied by drooling of food and saliva from the paralyzed lip. Blurred vision and ocular pain from exposure and dryness may interfere with the patient’s ability to perform an occupation or interact socially. Many patients with facial palsy experience depression or severe discouragement. Effective management of ocular problems by the ophthalmologist can have a profound effect on the patient’s rehabilitation. The ophthalmologist managing facial palsy should be aware of wide-ranging choices in the medical and surgical armamentarium to treat facial palsy. This chapter describes the varying clinical dimensions of facial palsy so that treatment can be individualized for effective management. The facial nerve (cranial nerve VII) has four important functions: 1. The facial motor nucleus controls muscles of facial expression, including the orbicularis oculi. 2. The superior salivatory nucleus sends parasympathetic fibers for lacrimal gland secretion and salivary secretion. 3. The nucleus solitarius receives sensory fibers of taste for the anterior two thirds of the tongue. 4. The trigeminal sensory nucleus receives sensory fibers for a small portion of the external ear. Facial motor fibers constitute about 58% of the 7,000 fibers of the facial nerve, while preganglionic fibers for tearing and salivation represent about 24%. The facial nerve leaves the cerebellopontine angle caudal to the trigeminal nerve adjacent to the nervus intermedius and then enters the internal auditory canal of the temporal bone. Large lesions of cranial nerve VII or VIII may cause loss of corneal sensation from pressure on the trigeminal nerve. The 30-mm course through the temporal bone is the longest interosseous course of any cranial nerve, which makes the facial nerve vulnerable to swelling. Three branches leave the facial nerve within the temporal bone. The first, and most important, arises at the geniculate ganglion just as the nerve makes a sharp bend, or genu, to head posteriorly. These fibers for lacrimal and palatine gland secretion constitute the greater superficial petrosal nerve carrying lacrimal secretory fibers to the pterygopalatine ganglion.