facial nerve examination

1. Dr. Shahnawaz Alam
Guided by: Dr. Vikas Chandra Jha
HOD, Dept. of Neurosurgery
Moderated by: Dr. Saraj kumar Singh
Faculty, Dept. of Neurosurgery
Facial Nerve Examination

2. Content
• Introduction
• Anatomy
• Clinical Examination
• Applied aspect

5. 1. Supranuclear: Fibers in cerebral
cortex to brain stem
2. Brain stem/intramedullary: from
BS nuclei to its exit point
3. Intra-cranial/cisternal(12 mm): exit
point to entry into IAC
4. Meatal (10 mm): Within Internal
Auditory Canal
5. Labyrinthine (4 mm): Fundus of
I.A.C. to Geniculate ganglion
6. Tympanic (11 mm): Geniculate
ganglion to pyramid
7. Mastoid (13 mm): Pyramid to
stylomastoid foramen
*
**

6. Anatomy of the cisternal and meatal segments
CN VII and VIII exit the brainstem at the CPA (cisternal segment) and enter
the IAC together.CN VII is anterior and superior to CN VIII in the IAC

7. Blood Supply Of The Facial Nerve

10. CLINICAL EXAMINATION

11. Examination of the Motor Functions
Inspection: Facial symmetry at resting position/Atrophy and fasciculations/
Spontaneous blinking/synkinesia/nasolabial fold with forehead wrinkles/width of
palpebral fissure/Observe movements during spontaneous/voluntary facial expression
Facial synkinesias myasthenic smile or snarl parkinsonism
Progressive SNP

12. • Testing the temporal branch: patient is asked to frown and wrinkle his or her forehead
• Testing the Zygomatic branch: patient is asked to close their eyes tightly
• Testing the buccal branch: Puff up cheeks (buccinator)/ Smile and show teeth (orbicularis oris)/ Tap
with finger over each cheek to detect ease of air expulsion on the affected side

13. Examination of Sensory Functions
• Hypesthesia of posterior wall of EAM:
proximal CN VII lesions
• Taste on anterior two-thirds of the
tongue: sweet/salty/bitter/sour

14. Examination of Secretory Functions
• History and observation: tearing/salivation
• Lacrimal and nasolacrimal reflex

15. • Little practical value
• Corneal Reflex: Afferent- CN V1,efferent- CN VII
• Stapedius reflex: by Impedance audiometry, Absence or a
reflex less than half the amplitude is due to a lesion
proximal to stapedius nerve
• Orbicularis oculi reflex: focal/non-focal
• Auditory-palpebral/visuo-palpebral/trigemino-facial reflex
• Chovostek’s sign
Examinations of the reflexes

16. Disorders of functions

19. Peripheral Facial Palsy
• Flaccid weakness (c/o-numbness & wooden feeling)/ Ipsilateral side/ both upper and lower
face/paralysis is usually complete
• Flaccid side of face: smooth/no wrinkles/eye wide open/inferior lid sag (epiphora)/ flattened
nasolabial fold/drooping of angle of mouth
• Can't raise eyebrow/blow out cheek/ clinch or bare teeth
• Talk or smile with one side of mouth, drawn to sound side
• Flaccid cheek- food accumulates/cheek bite/ saliva or liquid spill
• Involved eye Both direct & consensual corneal reflex absent
Bell’s phenomenon
A. Patient is attempting to retract
both angles of the mouth
B. Patient is attempting to elevate
both eyebrows

20. Sir Charles Bell
Bell’s palsy
• Idiopathic PFP/frequently follow viral infection
• Facial weakness on waking (ischemia/narrow labyrinthine part;
enhancement on Gd MRI-SPECIFIC)
• F>>M, during pregnancy
• Criteria: diffuse PFP/sudden onset (1-2 days)/ paralysis reaches max.
within 3 weeks/ full or partial recovery within 6 Months
• Symptoms begin with pain behind ear f/b facial weakness within 1-2
days
• MC symptoms: increased tearing associated with pain in or around
ear/ taste abnormalities (dysgeusia 60%)
• Paralysis complete in both upper & lower face (70%)
• 80% Full recovery within 6 Months
• Aberrant nerve regeneration: synkinesia/crocodile tear
(1829):THE DISCOVERY OF
THE NERVE OF FACIAL
EXPRESSION
• Scottish surgeon,
anatomist & artist
• Book “Anatomy of facial
expression for artists”

21. Wartenberg syndrome
Others causes of PFP
Möbius syndrome
Millard-Gubler
Syndrome
Foville Syndrome
Melkerson-Rosethal
syndrome

22. Facial Weakness of Central Origin
• Weakness of C/L lower face with relative sparing of upper face/ paralysis rarely
complete
• Subtle weakness of orbicularis oculi But involvement of frontalis & corrugator is
unusual
• Always able to close eye/ Bell phenomenon absent/ corneal reflex present
• In most cases, facial asymmetry present in both voluntary & spontaneous facial
movement; But when it is more marked with one than other (Dissociation)
 Two variations:
1. Volitional/voluntary: Facial asymmetry more marked during voluntary
contraction/ Lesion of lower third of the precentral gyrus or the
corticobulbar tract
2. Emotional/mimetic: Thalamic or striatocapsular lesions

23. Diagnosis of Peripheral or Central Facial Weakness and Site of Injury

24. Voluntary Central Facial Weakness > Mimetic (Involuntary) Central Facial Weakness
Mimetic (Involuntary) Central Facial Weakness > Voluntary Central Facial Weakness

25. Abnormal Facial Movements
Hemifacial spasm
• Mostly d/t intermittent compression by an ectatic arterial loop in posterior circulation
( redundant loop of AICA- pulsation cause nerve demyelination)
• May be Sequele Facial synkinesia
• It begins with twitching in orbicularis oculi, progress to other terminal branches
• Fully developed HFS- repetitive, paroxysmal, involuntary, spasmodic, tonic-clonic contraction
of involved side of face
• Mouth twisted to involved side, nasolabial fold deepens, eye closes, there is contraction
frontalis muscle
• Spasm persist in sleep, increased on chewing/speaking
Tic Convulsif: HFS with trigeminal neuralgia
Facial Myokymia: continuous involuntary rippling & worm like facial contraction; brainstem lesions
Brissaud-Sicard syndrome: HFS with C/L hemiplegia; pontine lesion

26. Panel A: UMN type, Panel B: LMN type, Panel C: right hemifacial spasm

27. House-Brackmann grading system

28. Localization of Lesions Affecting CN VII

29. THANK YOU