facial nerve examination

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

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

4. 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

5. Blood Supply Of The Facial Nerve

6. CLINICAL EXAMINATION

7. 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

8. 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

9. 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

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

11. 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

12. Disorders of functions

13. Peripheral Facial Palsy F laccid 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 Patient is attempting to retract both angles of the mouth Patient is attempting to elevate both eyebrows

14. 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 ”

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

16. 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: Volitional/voluntary: Facial asymmetry more marked during voluntary contraction/ Lesion of lower third of the precentral gyrus or the corticobulbar tract Emotional/mimetic: Thalamic or striatocapsular lesions

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

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

19. 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

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

21. House-Brackmann grading system

22. Localization of Lesions Affecting CN VII

23. THANK YOU