Transcript Ear and Hearing

Inservice Review
Quinton Gopen, M.D.
UCLA Medical Center
Feb 27th, 2013
75 y.o. gentleman with vertigo when lays on right
side. Counterclockwise nystagmus seen with right
side down. Which semicircular canal is
responsible?
•
•
•
•
Left posterior
Left superior
Right lateral
Right posterior
Answer:
• Right posterior canal
Which type of nystagmus is most
suggestive of central etiology ?
choices:
• decreased with eye fixation
• nystagmus changes with changing eye position
• horizontal nystagmus
• motion induced nystagmus
• nystagmus which stops with fixed gaze
answer:
nystagmus changes with changing
eye position
What structure is under efferent
nerve control in the inner ear?
choices:
• inner hair cell
• stria vascularis
• outer hair cells
• spiral ligament
• Deiter’s cells
answer:
outer hair cells
What form of words is used to test in
SRT?
choices:
• phoneme
• spondee
• balanced
• recruited
• tri-syllabic
answer:
spondee
Pt jammed Qtip into ear now with
bloody discharge; has a perforation
of the TM as well as hearing loss,
vertigo, and nystagmus
choices:
• Bedrest
• Serial audiograms
• Middle ear exploration
• Lumbar Puncture
• Meclizine
answer:
middle ear exploration
Most common autoimmune disease
with middle ear involvement
choices:
• SLE
• polyarteritis nodosum
• Wegerner's
• RA
• Behcet's
• sarcoidosis
answer:
Wegner's granulomatosis
Most common virus implicated in
congenital hearing loss
choices:
• CMV
• Herpes
• Toxoplasmosis
• mumps
• Varicella
discussion: congenital CMV infection accounts for a
large amount of childhood deafness ~ 30-40k
infants/year - roughly 1% of all newborns. All infants
with congenital CMV infection shed the virus in high
titers in bodily secretions. Definitive diagnosis can
be confirmed by means of isolation of the virus from
urine or saliva with PCR techniques within the first 2
weeks of life.
answer:
CMV
In malignant otitis externa, what is
the best modality for following the
infection ?
choices:
• Gallium scan
• CT scan
• PET scan
• technetium scan
• MRI scan
discussion: technetium bone scan evaluates
osteoblastic activity and is excellent for localizing
the infection but will not normalize after infection
has resolved. Gallium bone scan evaluates
inflammation and follows the course of the
malignant otitis externa
answer:
gallium scan
Young woman with bilateral
moderate SNHL and diffuse thyroid
enlargement; what is next step ?
choices:
• perchlorate level
• measure antithyroglobulin antibodies
• renal UTZ
• thyroid uptake scan
• head CT
discussion: The woman has Pendred's syndrome,
which is a defect in tyrosine iodination and
presents as multinodular goiter at 8-14yrs old
from failure of iodine organification - diagnosed
by perchlorate levels (a positive perchlorate test is
decreased perchlorate discharge). The treatment
is exogenous thyroid hormone with thyroidectomy
typically not required.
answer:
perchlorate level
Audiogram of pt with otosclerosis.
H/o LT stapes now with very poor
hearing in left ear (PTA 60dB, discrim
20%) Now with large air bone gap in
right ear.
choices:
• hearing aids
• right stapedectomy
• left stapedectomy
• fluoride
• left cochlear implant
answer:
hearing aids
What happens after stimulation of
Jacobsen's nerve ?
choices:
• increased lacrimation
• decreased lacrimation
• increased submandibular gland flow
• decreased submandibular gland flow
• increase parotid gland flow
discussion: Jacobsen's nerve, a branch of cranial
nerve IX provides parasympathetic innervation via
the otic ganglion and auriculotemporal nerve to
the parotid gland.
answer:
increase parotid gland flow
Pt c/o pain in EAC with hand drawn
picture showing area just inferior to
TM - what is innervation?
choices:
• Vagus
• Trigeminal
• Occipital
• greater auricular
• facial
?
discussion: Innervation
of the inferior aspect of
the EAC comes from the
vagus nerve
see picture for
innervation of the EAC
quadrants
answer:
vagus
Pt with resection of mastoid facial
neuroma how best reconstruct ?
choices:
• XII-VII anastamosis
• cable graft
• VII-VII crossover
• pedicled temporalis flap
• facial sling
discussion: For facial nerve reconstruction, there
is a definite order of preference in the method of
repair. The first choice is always direct
reapproximation of severed nerve ends, however
due to tissue loss or in this case tumor resection
this is not always possible. The second choice is
a cable graft, with things like XII-VII and VII-VII
coming after the cable graft in order of preference.
answer:
cable graft
Profuse bleeding during resection of
a tumor involving the jugular bulb what is blood supply ?
choices:
• superior petrosal sinus
• transverse sinus
• inferior petrosal sinus
• ascending pharyngeal
• external carotid
discussion: the jugular bulb becomes the internal
jugular vein inferiorly; superiorly the sigmoid
sinus and the inferior petrosal sinus culminate to
form the jugular bulb, and profuse bleeding
certainly can arise in this area. The superior
petrosal sinus drains into the lateral extent of the
sigmoid sinus. Of the two listed, the inferior
petrosal sinus is the best choice.
answer:
inferior petrosal sinus
Maximum conductive loss comes
from what ?
choices:
• intact drum with ossicular discontinuity
• total perforation
• inferior perforation
• superior perforation
• middle ear effusion
discussion: A maximum conductive hearing loss
is obtained when there is ossicular discontinuity
in the presence of an intact eardrum and is around
60dB
answer:
intact drum with ossicular
discontinuity
Which nerve is responsible for
gustatory sweating ?
choices:
• Glossopharyngeal
• Facial
• Chordae
• Lingual
• Vidian nerve
discussion: the glossopharyngeal nerve
innervates the parotid gland via the following
pathway: inferior salvatory nucleus (medulla) glossophayryngeal nerve (Jacobsen's nerve) lesser superficial petrosal nerve - otic ganglion
(now postganglionic fibers) - auriculotemporal
nerve (CNV3) - partoid gland
After the parotid gland is cut out, the
parasympathetic fibers aberently regenerate into
the sweat glands which leads to Frey's syndrome,
also known as gustatory sweating
answer:
glossopharyngeal
Tumor at fundus with intact hearing
what would be best approach ?
choices:
• Middle fossa
• Suboccipital
• Retrosigmoid
• Translabyrinthine
• Infracochlear
discussion: There are three main types of
approach to CP angle tumors: translab,
retrosigmoid and middle fossa. The translab can
get out any size tumor but has the down side of
destroying any residual hearing. The middle
fossa and retrosigmoid approaches spare hearing
but can only be used in certain instances: middle
fossa is best for small tumors at the fundus (very
far lateral just as nerve enters cochlea) whereas
retrosigmoid (aka suboccipital) is best for tumor
at the meatus (very far medially where the nerve
exits the brainstem at the CP angle.
answer:
middle fossa
Which pt will do worst with a
cochlear implant ?
choices:
• postlingually deaf adult
• postlingually deaf child
• prelingually deaf child of short duration
• sign language before implant
• congenitally deaf
discussion: cochear implants (CI) depend on an
intact cochlear nerve which can be stimulated, so
the patients which do worse have the least viable
cochlear nerve - this would be the congenitally
deaf patient
answer:
congenitally deaf
Best hearing test for 8 month old ?
choices:
• Behavioral
• Play
• Conventional
• Visual reinforced
• Infant
Discussion:
conventional audiometry
3-4 years
behavioral audiometry
0-6months
visual reinforced
7-36months
play audiometry
36-60months
answer:
visual reinforced
CROS hearing aid is for ?
choices:
• unilateral profound hearing loss
• bilateral profound hearing loss
• unilateral conductive hearing loss
• chronic draining ear
• poor manual dexterity
answer:
unilateral profound hearing loss
What structure is contained in the
cochlear aqueduct ?
choices:
• loose arachnoid tissue
• endolymphatic duct
• cochlear artery
• singular nerve
• subarcuate artery
discussion: The structure contained inside the
cochlear aqueduct is called the periotic duct and
consists of loos connective tissue/loose
arachnoid tissue
answer:
loose arachnoid tissue
While in surgery, the surgeon notes
that he cog has been eroded by
cholesteatoma, what is the most
likely other structure to be affected ?
choices:
• lateral semicircular canal
• verticle facial nerve
• labyrinthine facial nerve
• tympanic facial nerve
• Posterior semicircular canal
discussion: The cog is a ridge of bone that extends
inferiorly from the tegmen and separates the anterior
epitympanum. The cog lies immediately superior to
the cochleariform process. The tympanic segment of
the facial nerve courses under the base of the cog.
answer:
tympanic segment of facial nerve
Site of ototoxicity of cisplatin ?
choices:
• basal cochlea
• apical cochlea
• saccule
• utricle
• lateral semicircular canal
discussion: cisplatin causes selective loss of
outer hair cells in basal turn of the cochlea;
toxicity related to dose of individual cycle rather
than total dose of therapy; elderly and young
children more at risk
answer:
basal cochlea
What is the most common
complication of cochlear implantation ?
choices:
• flap necrosis
• facial nerve stimulation
• misplaced electrode
• meningitis
• encephalocele
discussion: Ear, Nose & Throat Journal, Dec, 1999, by
Arvind Kumar, Richard Mugge, Marci Lipner
Flap-related problems continue to be the most
common complications, although their rates have
fallen from 5.44% in 1988 [1] to 2.79% in l995. [5] The
incidence of compressed/misplaced electrodes has
also declined, from 1.74 to 1.18%, as has the incidence
of facial paresis, from 1.74 to 0.56%.
answer:
flap necrosis
Which cells are first damaged with
noise exposure?
choices:
• outer hair cells at apical turn
• outer hair cells at basal turn
• inner hair cells at apical turn
• inner hair cells at base
• Claudius cells
discussion: high frequencies are lost first in noise
exposure, which corresponds to the basal portion
of the cochlea - and outer hair cells are more
sensitive than inner hair cells to noise exposure so outer hair cells in the base
answer:
outer hair cells at basal turn
Cerebellopontine mass
hypointense on T1 and
hyperintense on T2
Also no gadolinium enhancement
choices:
• cholesterol granuloma
• lipoma
• arachnoid cyst
• Meningioma
• acoustic neuroma
discussion: T1 images fat lights up whereas on T2
images water lights up; here we have a mass lighting
up on T2 (like water) without enhancement when
gadolinium is given. We can therefore rule out
acoustic neuroma and meningioma which would
enhance with gad and light up on T1 images.
Arachnoid cyst is like a big water bag so this is a good
possibility and is often found in the CP angle and
doesn't enhance with contrast! Cholesterol granuloma
is one of the few things that will be intense on both T1
and T2 images. Lipoma has T1 hyperintensity.
answer:
arachnoid cyst
Most common petrous apex lesion ?
choices:
• Cholesteatoma
• Mucocele
• cholesterol granuloma
• teratoma
• malignant schwannoma
discussion: Cholesterol granuloma is the most
common lesion of the petrous apex. It is approximately
10 times more common than cholesteatoma and 40
times more common than mucocele.
answer:
cholesterol granuloma
Child with otitis media and
fluctuance in subQ tissue over
mastoid with fever but no facial
nerve paralysis
choices:
• PET
• PET and simple mastoidectomy
• IV ABX
• radical mastoidectomy
• wide myringotomy
discussion: Pt has a subperiosteal abscess
(fluctuance) which must be drained via a simple
mastoidectomy
answer:
PET and simple mastoidectomy
During a tympanoplasty
mastoidectomy which medicaiton
should anesthesia use to paralyze
the patient ?
choices:
• Atracuronium
• Curare
• Pancuronium
• Rocuronium
• Succinylcholine
discussion: the idea here is you must be able to
monitor the facial nerve funtion throughout the case so the shortest acting agent is the best –
succinylcholine
answer:
succinylcholine