Onset of symptoms

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  Etiology: Bell’s palsy, surgery, and stroke

  
  
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  Unilateral or bilateral; complete or incomplete

  
  
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  Duration and rate of progression: Acute, subacute, or chronic

Associated symptoms: Headaches, blurred vision, dry eyes, vertigo, hearing loss, otorrhea, oral incompetence, speech difficulties, snoring, and nasal obstruction

History of trauma, infections (Bell’s palsy, Ramsay-Hunt, Lyme disease, TB), neuromuscular disease (Myasthenia Gravis, Charcot–Marie–Tooth, Guillain–Barre), tumors (Neurofibromatosis Type II), diabetes, travel history, pregnancy, family history, and surgical history (otologic surgery, rhytidectomy, parotidectomy)

Perform complete head, neck, and cranial nerve examination

Examine all branches of facial nerve (complete or incomplete involvement)

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  Temporal (Frontal): Elevation of forehead

  
  
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  Zygomatic: Closure of orbicularis oculi

  
  
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  Buccal: Elevation of cheek and oral commissure

  
  
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  Marginal mandibular: Depression of oral commissure and lower lip

  
  
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  Cervical: Contraction of platysma

Eyes: Evaluate eye closure, vision, corneal defects, and ectropion

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  Schirmer’s test (see Chapter 25)

  
  
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  Bell’s phenomenon (see Chapter 25): If absent, there is greater concern for corneal injury

Evaluate facial movements at rest and in multiple different expressions

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  Assess midline deviation, degree of excursion with movement

  
  
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  Assess brow movement, nasal valve function, and oral competence

  
  
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  Synkinesis: Involuntary contraction of additional facial muscles with voluntary facial movement—due to aberrant neuroregeneration

Assess overall muscle status (hypertonic, normal, or atrophic), voluntary and involuntary movements (synkinesis, dyskinesis, fasciculations)

Hematologic work-up: Complete blood count (CBC) (evaluate for infection, leukemia) and Lyme titer

High resolution contrast-enhanced computed tomography (CT) or gadolinium-enhanced magnetic resonance imaging (MRI)

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  Should include the brain (temporal bone) and parotid gland

Possible biopsy: Facial nerve, lip (for salivary tumors), and FNA of parotid mass

Electrodiagnostic studies: Nerve conduction studies, electromyography (EMG)

Electroneurography (ENoG): Compares amplitude of summation potentials of paralyzed face to normal side