• Affected side of face
• Affected segments of face
  • Hemi-face-- indicates unilateral pathology rather than bilateral
  • Forehead sparing – involvement of the mid and lower face with intact upper facial movement may indicate central nervous system insult or distal peripheral branch insult (e.g. parotid tumor or trauma to peripheral upper nerve branch)
  • Segmental – indicates involvement of segmental branches of facial nerve
• Onset of symptoms
  • Date – differential diagnosis, associated work-up, and possible treatment options rely on timing since onset of paralysis
  • Progression — rate of onset can indicate etiology (e.g. Bell’s palsy onset 24-72 hours)
  • Treatment at onset – was there an initial evaluation at the time of onset, how was it managed (e.g. steroids, antiviral medications, imaging) 
• Degree of paralysis
  • Incomplete/weakness/paresis versus complete/paralysis
  • House-Brackmann scale – tool for grading of facial nerve function 
• Associated factors give clues to etiology and further required work-up (e.g. cranial nerve deficits, previous facial paralysis episodes)
  • Otologic symptoms – dizziness, tinnitus, otorrhea, hearing loss, changes in taste or salivation
  • Face/Ear/Neck rash (e.g. herpes vesicles) – may indicate prolonged recovery
  • Head & neck symptoms – parotid or neck mass, progression of incomplete to complete paralysis, other cranial nerve deficits
  • Atypical presentation (e.g. Bell’s palsy with onset beyond typical 24-72 hours), recurrent or bilateral paralysis, concurrent neurologic findings

• Flaccid paralysis – absent movement on the hemi-face
• Non-flaccid paralysis – some movement present that may include:
  • Facial weakness/paresis – some movement; weakness may be segmental 
  • Synkinesis 
  • Mixed weakness/paresis & Synkinesis

Synkinesis – involuntary movements of one region of face due to voluntary/spontaneous movement in another region, which may include hyperkinesia 

• Symptoms 
  • Often present with inability to smile due to synkinetic muscles opposing zygomatic function
  • Patients may complain of tightness, spasm, facial pain
• Examination 
  • Discoordinated musculature
    • E.g. eye closure with attempted mouth movements
  • Hypercontracted musculature
    • Distortion from asymmetrically increased muscular tone  
  • Mixed – examine each segment for weakness also present
• Early interventional options before synkinesis develops
  • Eye protection (see Ocular Management of Incomplete Eye Closure)
  • Refrain from maximal-effort exercises of facial muscles which may worsen asymmetry (i.e. strengthens other muscles)
  • Avoid electrical stimulation – attempted stimulation of paretic area may result in abnormal movements
• Interventional options to treat synkinesis 
  • Chemodenervation injections – temporary inhibition of synkinetic musculature 
    • Most commonly Botox therapy to synkinetic musculature
    • Can use small quantities on contralateral muscles for improvement in symmetry  
  • Neuromuscular retraining therapy
    • Facial training may improve expression through muscle coordination
    • Often administered by occupational therapist 
  • Selective neurolysis surgery or muscle excision 
    • Inhibition of synkinetic musculature through direct muscle excision or removal of neural input

** Remember that synkinesis can co-exist with nerve palsy and impact facial distortion.**

• Wrap-around sunglasses
• Frequent lubrication (e.g. Optive)
• Ophthalmic ointment (e.g. Lacrilube)
• Nighttime moisture chamber 
• Eye taping
• Suture tarsorrhaphy 

For Intact Musculature: Nerve Transfer Reanimation Options

• Intact Proximal Nerve & Distal Nerve (e.g. main trunk disruptions)
  • Primary neurorrhaphy
    • Primary suture repair gold standard
    • Proximal peripheral nerve attachment to distal nerve or branches
  • Cable graft 
    • Best for large defects between distal and proximal nerve ends
    • Common donor nerve grafts – greater auricular nerve & sural nerve
• Unavailable Proximal Nerve, Intact Distal Nerve (e.g. brainstem lesion)
  • Nerve substitution indicated if main trunk of the facial nerve is damaged or unavailable for graft, but distal nerves and corresponding muscles are viable
  • Requires coaptation of other motor nerves 
    • Common ipsilateral donor nerves – masseteric, hypoglossal, cross-face nerve graft 
    • Contralateral donor nerve to intact distal nerve (i.e. cross face nerve graft)
  • Note: These motor nerves also used when main trunk of the facial nerve is damaged/unavailable and musculature is NOT intact. Donor motor nerves drive free tissue transfer

For Non-Intact Musculature: Muscle Transfer Reanimation Options

• Static reconstruction versus Dynamic Reanimation 
  • Dynamic reanimation reestablishes voluntary contractile muscle 
    • Goal: achieve smile either spontaneous with cross face nerve graft or with purposeful activation (e.g. biting or tongue movement)
    • Best suited for optimal smile restoration 
  • Dynamic muscle options when native musculature non-intact (see below)
    • Regional muscle transfer
    • Free muscle transfer with nerve transfer 
  • Static reconstruction procedures aim to optimize suspension of facial structures, 
    • Goals are to improve oral competence, eye closure, facial symmetry at rest, minimize synkinesis and mass movement 
    • Best suited for upper face rehabilitation, midface tissue resuspension, or for those with inability to tolerate larger procedures 
    • Often performed in conjunction with dynamic reanimation procedures. 
    • Examples: upper eyelid weighting and lid procedures; fascia lata sling for nasolabial fold elevation; also for external nasal valve collapse
• Free tissue transfer versus regional transfer 
  • Free flap candidates have reasonable life expectancy without significant comorbidities 
    • Common harvest sites – gracilis muscle (most common), pectoralis minor muscle, latissimus dorsi muscle 
    • Common nerve donors 
      • Split hypoglossal – significant tongue morbidity, synkinesis, poor 
      • Masseteric/Trigeminal nerve – easy volitional triggering, low donor site morbidity, good oral commissure excursion; mastication-triggered activation
      • Cross-facial nerve graft – used with autologous long sural nerve graft; achieves good resting tone, only technique that provides emotive smile; less commissure excursion, blink-triggered activation
  • Regional pedicled flap sites allow for dynamic reanimation of non-intact native musculature without need for separate donor nerve
    • Temporalis muscle – reliable anatomy and vasculature, minimizes hollowing of temporal region; results in possible alopecia of harvest site; relatively contraindicated in edentulous, preoperative wasting, and trigeminal dysfunction 

1. What are some medical etiologies necessitating evaluation in new onset facial nerve paresis or paralysis?
2. How many zones of the face require analysis? What are the zones?
3. What can lead to facial distortion when nerve palsy does not fully account for deficits?
4. Which repair option is ideal for a small defect that is under moderate tension?
5. Which technique in reanimation produces the best spontaneous smile?