ENoG - class

6/18/15
Electroneurography (ENoG)
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Facial Nerve Etiologies
EXTRACRANIAL
INTRATEMPORAL
INTRACRANIAL
Extracranial Facial Nerve Etiologies
! 
Traumatic
"  Facial
lacerations
forces
"  Penetrating wounds
"  Mandible fractures
"  Iatrogenic injuries
"  Blunt
! 
Neoplastic
"  Tumors
of EAC and ME
nerve neuroma
"  Metastatic lesions
"  Facial
! 
Congenital
"  Absence
of facial musculature
Intratemporal Facial Nerve Etiologies
! 
Traumatic
"  Fractures
of petrous pyramid
injuries
"  Iatrogenic
"  Penetrating
! 
Neoplastic
"  Glomus
tumor
"  Cholesteatoma
"  Acoustic
neurinomas
"  Meningiomas
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Facial Nerve Etiologies
! 
Infectious
"  Herpes
zoster oticus
otitis media
"  Chronic otitis media
"  Malignant otitis media
"  Chicken pox
"  Mumps
"  Acute
! 
Idiopathic
! 
Congenital
"  Bell’s
palsy
"  Osteopetroses
Intracranial Facial Nerve Etiologies
#  Syndromes
!  Melkersson-Rosenthal
$ Rare,
recurrent facial paralysis
!  Guillain-Barre
$ Infectious
polyneuritis; probably viral
Electroneurography
% Objective test of Nerve VII integrity
% Purpose:
% 2 loci
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ENoG – Testing Window
! 
Wallerian degeneration
! 
Testing after 21 days since onset is of little value
! 
Best time to test is as soon after 72 hours post injury as
possible
Facial Nerve Dysfunction Classification
#  House-Brackmann Scale
!  Grade
I
II
!  Grade III
!  Grade IV
!  Grade V
!  Grade VI
!  Grade
1/6
2/6
3/6
4/6
5/6
6/6
Normal
Mild
Moderate
Moderately severe
Severe
Total paralysis
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Bell’s Palsy
% Named after Sir Charles Bell (Scottish surgeon)
% Symptoms
Etiologies of Bell’s Palsy
!  Viral
infection
!  Influenza
Bell’s Palsy Demographics
#  40,000
#  Prevalence among men and women
#  Ages 16-60
#  At risk
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Bell’s Palsy Diagnosis
% Symptoms
% Imaging
% ENoG
Treatment for Bell’s Palsy
% No cure
% Symptoms last:
% Some relief:
% If eye is involved
% Surgery
Bell’s Palsy Prognosis
% Usually good
% Improvement
% Recover - 3-6 months
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ENog Protocol
% Placement of electrodes
% Huge response
% Instructions to patient:
ENOG Protocol
% Use non-conductive chair
% R/o contra-indications
% Test “good side” first
% Bipolar electrical stimulation
% Only need 2-3 repetitions
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References
% Beck & Hall (2001) Hearing Journal, 54 (30), 36-45.
% Beck & Beneke (1993) JAAA, 4 (2), 109-115.
% National Institute of Neurological Disorders—Bells’
Palsy Fact Sheet
% Baylor College of Medicine, Depatment of
Otorhinolaryngology and Communicative Sciences
http://www.bcm.tmc.edu/oto/studs/face.html
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