History of disease, facial nerve grading systems & clinical evaluation

Obtaining an accurate history of the onset, progress and associated symptoms of newly acquired facial nerve palsy is extremely helpful in determining the potential cause of the palsy. More importantly it serves as a guide for prognosis and timing of any necessary surgical intervention. Acute versus chronic facial nerve palsy, complete versus incomplete facial nerve palsy, recovery and recurrence of the disease will be discussed. The gold standard for grading facial nerve function is the House‐Brackmann grading scale. Due to the limitations and subjectivity of this scale, several new scales of various degrees of objectivity and ease of use have been introduced. These include the Nottingham system, the Sunnybrook scale, the Yanagihara and the Sydney system, all with their advantages and disadvantages. Clinical evaluation of a patient with facial nerve palsy include evaluation of upper eyelid retraction, blink reflex, lagophthalmos, brow ptosis, paralytic ectropion, midface ptosis, mouth symmetry, platysma muscle strength, hearing, corneal sensation, Bell’s phenomenon, tear function and synkinesis.