Point 14 Intro Pathway Deficit Note Overview Problems Contents Anatomy

A unilateral lesion interrupting the axons of C.N. VII results in the following: On the ipsilateral side, the forehead is immobile, the corner of the mouth sags, the nasolabial folds of the face are flattened, facial lines are lost, and saliva may drip from the corner of the mouth. The patient is unable to whistle or puff the cheek because the buccinator muscle is paralyzed. When the patient is smiling, the normal muscles draw the contralateral corner of the mouth up while the paralyzed corner continues to sag. Corneal sensitivity remains (C.N. V), but the patient is unable to blink or close the eyelid (CN VII). To protect the cornea from drying, therapeutic closure of the eyelids or other measures are taken (patient wears an eye mask, or lids are closed with sutures). Because of the paralysis of the stapedius muscle, which normally dampens the amplitude of the vibrations of the ear ossicles, the patient will experience sounds as uncomfortably loud. THIS IS CALLED HYPERACUSIS. REMEMBER, THERE WILL BE ATROPHY OF ALL OF THE ABOVE MUSCLES (i.e. Lower Motor Neuron).