Neuro-ophthalmologic complications and manifestations of upper and lower motor neuron facial paresis.

The facial nerve (cranial nerve VII) courses a long pathway beginning in the precentral gyrus and ending at the facial muscles, lacrimal and salivary glands, and structures of the inner ear. Lesions along this pathway, clinically divided into upper and lower motor neuron lesions, present with unique characteristics that assist the physician in identifying the lesion site. The sequelae particularly of peripheral CN VII palsies, may result in significant and chronic damage to the cornea that may be challenging for the physician and patient.