Labyrinth
Infection of CNS spreads in inner ear through
A |
Cochlear aqueduct |
|
B |
Endolymphatic sac |
|
C |
Vestibular aqueduct |
|
D |
Hyrtle fissure |
Infection of CNS spreads in inner ear through
A |
Cochlear aqueduct |
|
B |
Endolymphatic sac |
|
C |
Vestibular aqueduct |
|
D |
Hyrtle fissure |
Infection of CNS spreads in inner ear through
A |
Cochlear aqueduct |
|
B |
Endolymphatic sac |
|
C |
Vestibular aqueduct |
|
D |
Hyrtle fissure |
Infection of CNS spreads in inner ear through
A |
Cochlear aqueduct |
|
B |
Endolymphatic sac |
|
C |
Vestibular aqueduct |
|
D |
Hyrtle fissure |
Endolymph in the inner ear:
A |
Is a filterate of blood serum |
|
B |
Is secreted by Stria vascularis |
|
C |
Is secreted by Basilar membrane |
|
D |
Is secreted by Hair cells |
Endolymph in the inner ear:
A |
Is a filterate of blood serum |
|
B |
Is secreted by Stria vascularis |
|
C |
Is secreted by Basilar membrane |
|
D |
Is secreted by Hair cells |
Is secreted by Stria vascularis [Ref: Ds. of ENT by P.L. Dhingra 5/e p12] Repeat from May 09
There are 2 main fluids in the inner ear:
- Endolymph
– It fills the entire membranous labyrinth
– Resembles intracellular. fluid, being rich in K ions.
– It is secreted by the secretory cells of the stria vascularis of the choclea and by the dark cells (present in the utricle and near the ampullated ends of semicircular ducts).
- Perilymph
– It fills the space between the bony and the membranous labyrinth.
– It resembles extra cellular fluid being rich in Na ions.
– It communicates with CSF through the aqueduct of cochlea which opens into the scala tympani near the round window.
– There are 2 views regarding its formation:
i) It is a filterate of blood serum and is formed by capillaries of the spiral ligament
ii) It is a direct continuation of CSF and reaches the labyrinth via aqueduct of cochlea.
Most potential route for transmission of Meningitis from CNS to Inner ear is:
A |
Cochlear Aqueduct |
|
B |
Endolymphatic sac |
|
C |
Vestibular Aqueduct |
|
D |
Hyrtl’s fissure |
Most potential route for transmission of Meningitis from CNS to Inner ear is:
A |
Cochlear Aqueduct |
|
B |
Endolymphatic sac |
|
C |
Vestibular Aqueduct |
|
D |
Hyrtl’s fissure |
Most potential route for transmission of Meningitis from CNS to Inner ear is Cochlear Aqueduct.
The scala tympani is closed by secondary tympanic membrane; it is also connected with the subarachnoid space through the aqueduct of cochlea.
Hence the infections from meninges can spread to inner ear.
A 38 year old male presented with a suspected diagnosis of suppurative labyrinthitis. A positive Rinne’s test and positive fistula test was recorded on initial examination. The patient refused treatment, and returned to the emergency department after 2 weeks complaining of deafness in the affected ear. On examination, fistula test was observed to be negative. What is the likely expected finding on repeating the Rinne’s test?
A |
True Positive Rinne’s Test |
|
B |
False Positive Rinne’s Test |
|
C |
True Negative Rinne’s Test |
|
D |
False Negative Rinne’s Test |
A 38 year old male presented with a suspected diagnosis of suppurative labyrinthitis. A positive Rinne’s test and positive fistula test was recorded on initial examination. The patient refused treatment, and returned to the emergency department after 2 weeks complaining of deafness in the affected ear. On examination, fistula test was observed to be negative. What is the likely expected finding on repeating the Rinne’s test?
A |
True Positive Rinne’s Test |
|
B |
False Positive Rinne’s Test |
|
C |
True Negative Rinne’s Test |
|
D |
False Negative Rinne’s Test |
A positive Rinnie’s test is seen in normal people and in sensorineural deafness, and a positive fistula test implies that the labyrinth is still functioning.
On otological examination, all of the following will have positive fistula test, EXCEPT:
A |
Dead ear |
|
B |
Labyrinthine fistula |
|
C |
Hypermobile stapes footplate |
|
D |
Following fenestration surgery |
On otological examination, all of the following will have positive fistula test, EXCEPT:
A |
Dead ear |
|
B |
Labyrinthine fistula |
|
C |
Hypermobile stapes footplate |
|
D |
Following fenestration surgery |
In a positive fistula test, a pressure change in the external ear canal is transmitted to the labyrinth by an abnormal opening thereby producing nystagmus and vertigo.
It also implies that the labyrinth is still functioning, and is absent when labyrinth is dead.
The abnormal opening caused by a cholesteatoma eroding into the horizontal semicircular canal, following fenestrating operations and rupture of round window membrane are associated with positive fistula test.
Hypermobile stapes footplate is associated with false positive fistula test.
A 40 year old male patient has a suspected diagnosis of suppurative labyrinthitis. A positive Rinne’s test and positive fistula test was recorded on initial examination. The patient avoided treatment and returned to the emergency department after 3 weeks complaining of deafness in the affected ear. On examination, fistula test was observed to be negative. What is the likely expected finding on repeating the Rinne’s test?
A |
True Positive Rinne’s Test |
|
B |
False Positive Rinne’s Test |
|
C |
False Negative Rinne’s Test |
|
D |
True Negative Rinne’s Test |
A 40 year old male patient has a suspected diagnosis of suppurative labyrinthitis. A positive Rinne’s test and positive fistula test was recorded on initial examination. The patient avoided treatment and returned to the emergency department after 3 weeks complaining of deafness in the affected ear. On examination, fistula test was observed to be negative. What is the likely expected finding on repeating the Rinne’s test?
A |
True Positive Rinne’s Test |
|
B |
False Positive Rinne’s Test |
|
C |
False Negative Rinne’s Test |
|
D |
True Negative Rinne’s Test |
Infection of CNS spreads to the inner ear through which of the structures?
A |
Cochlear Aqueduct |
|
B |
Endolymphatic sac |
|
C |
Vestibular Aqueduct |
|
D |
Hyrtle’s fissure |
Infection of CNS spreads to the inner ear through which of the structures?
A |
Cochlear Aqueduct |
|
B |
Endolymphatic sac |
|
C |
Vestibular Aqueduct |
|
D |
Hyrtle’s fissure |
Cochlear aqueduct: connects scala tympani to CSF
The labyrinth maintains connections with the central nervous system (CNS) and subarachnoid space by way of the internal auditory canal and cochlear aqueduct.
Bacteria may gain access to the membranous labyrinth by these pathways or through congenital or acquired defects of the bony labyrinth.
Inner ear contain endolymph and perilymph. Which of the following structure of the inner ear produces endolymph?
A |
Is a filtrate of blood serum |
|
B |
Is secreted by Stria vascularis |
|
C |
Is secreted by Basilar membrane |
|
D |
Is secreted by Hair cells |
Inner ear contain endolymph and perilymph. Which of the following structure of the inner ear produces endolymph?
A |
Is a filtrate of blood serum |
|
B |
Is secreted by Stria vascularis |
|
C |
Is secreted by Basilar membrane |
|
D |
Is secreted by Hair cells |
Endolymph in the inner ear:
A |
Is a filtrate of blood serum |
|
B |
Is secreted by Stria vascularis |
|
C |
Is secreted by Basilar membrane |
|
D |
Is secreted by Hair cells |
Endolymph in the inner ear:
A |
Is a filtrate of blood serum |
|
B |
Is secreted by Stria vascularis |
|
C |
Is secreted by Basilar membrane |
|
D |
Is secreted by Hair cells |
Otoacoustic emissions arise from which of the following structure of the inner ear?
A |
Inner hair cells |
|
B |
Outer hair cells |
|
C |
Both inner and outer hair cells |
|
D |
Organ of Corti |
Otoacoustic emissions arise from which of the following structure of the inner ear?
A |
Inner hair cells |
|
B |
Outer hair cells |
|
C |
Both inner and outer hair cells |
|
D |
Organ of Corti |
Endolymph in the inner ear:
A |
has low concentration of K+ and high concentration of Na+ |
|
B |
Is secreted by Stria vascularis |
|
C |
Is secreted by Basilar membrane |
|
D |
None is true |
Endolymph in the inner ear:
A |
has low concentration of K+ and high concentration of Na+ |
|
B |
Is secreted by Stria vascularis |
|
C |
Is secreted by Basilar membrane |
|
D |
None is true |
Labyrinthine artery is a branch of?
A |
Posterior inferior cerebellar artery |
|
B |
Vertebral artery |
|
C |
Posterior cerebral artery |
|
D |
Anterior inferior cerebellar artery |
Labyrinthine artery is a branch of?
A |
Posterior inferior cerebellar artery |
|
B |
Vertebral artery |
|
C |
Posterior cerebral artery |
|
D |
Anterior inferior cerebellar artery |
The labyrinthine artery (auditory artery, internal auditory artery), a long slender branch of the anterior inferior cerebellar artery (85%-100% cases) or basilar artery.
The blood supply to inner ear is derived from:
A |
Superior cerebellar artery |
|
B |
Posterior inferior cerebellar artery |
|
C |
Middle cerebral artery |
|
D |
Anterior inferior cerebellar artery |
The blood supply to inner ear is derived from:
A |
Superior cerebellar artery |
|
B |
Posterior inferior cerebellar artery |
|
C |
Middle cerebral artery |
|
D |
Anterior inferior cerebellar artery |
D. i.e. Anterior inferior cerebellar artery
Internal ear derives its blood supply from labyrinthine (internal auditory) artery which is usually a branch of anterior inferior cerebellar artery or sometimes of basilar artery.
Most potential route for spread of infection from CNS to inner ear
A |
Vestibular aqueduct |
|
B |
Cochlear aqueduct |
|
C |
Endolymphatic sac |
|
D |
Hyrtle fissure |
Most potential route for spread of infection from CNS to inner ear
A |
Vestibular aqueduct |
|
B |
Cochlear aqueduct |
|
C |
Endolymphatic sac |
|
D |
Hyrtle fissure |
Cochlear aqueduct is most potential route for spread of infection from CNS to inner earQ
Cochlear aqueduct & vestibular aqueduct are 2 bony channels (canals) that connect inner ear (cochlea & vestibule respectively) to intracranial sub arachnoid space. Vestibular aqueduct contains endolymphatic duct filled with endolymph, which does not communicate freely with CSF as it ends in a cul de sac and forms a closed space. Whereas perilymph filled cochlear aqueduct is in direct continuation with the CSF which makes it a most potential route of infection.
Hyrtle’s fissure is present in early embryonic life that normally obliterates by 24 weeks of gestation. When persistent it provides a connection from middle ear to subarachnoid space.
Inner ear is present in which bone:
A |
Parietal bone |
|
B |
Petrous part of temporal bone |
|
C |
Occipital bone |
|
D |
Petrous part of squamous bone |
Inner ear is present in which bone:
A |
Parietal bone |
|
B |
Petrous part of temporal bone |
|
C |
Occipital bone |
|
D |
Petrous part of squamous bone |
Inner ear bony labyrinth is:
A |
Strongest bone in the body |
|
B |
Cancellous bone |
|
C |
Cartilaginous bone |
|
D |
Membranous bone |
Inner ear bony labyrinth is:
A |
Strongest bone in the body |
|
B |
Cancellous bone |
|
C |
Cartilaginous bone |
|
D |
Membranous bone |
Bony labyrinth is an example of cartilaginous bone (i.e. a bone which ossification cartilage).
Infection of CNS spread in inner ear is through:
A |
Cochlear aqueduct |
|
B |
Endolymphatic sac |
|
C |
Vestibular aqueduct |
|
D |
Hyrtl fissure |
Infection of CNS spread in inner ear is through:
A |
Cochlear aqueduct |
|
B |
Endolymphatic sac |
|
C |
Vestibular aqueduct |
|
D |
Hyrtl fissure |
Cochlear aqueduct (Aqueduct of Cochlea) is a connection between scala tympani (containing perilymph) and the subarachnoid space (containing CSF). On occassions, particularly in young children, the Cochlear aqueduct is large and open.
Infection can spread to the inner ear from the infected CSF or vice versa, via the cochlear aqueduct resulting in severe profound hearing loss (meningitic labyrinthitis).
Labyrinthine artery is a branch of:
A |
Internal carotid artery |
|
B |
Basilar artery |
|
C |
Posterior cerebellar artery |
|
D |
Anteroinferior cerebellar artery |
Labyrinthine artery is a branch of:
A |
Internal carotid artery |
|
B |
Basilar artery |
|
C |
Posterior cerebellar artery |
|
D |
Anteroinferior cerebellar artery |
Labyrinthine artery is a branch of anteroinferior cerebellar artery but can sometimes arise from basilar artery.
It supplies whole of the inner ear.
Endolymph in inner ear:
A |
Is a filtrate of blood serum |
|
B |
Is secreted by striae vascularis |
|
C |
Is secreted by basilar membrane |
|
D |
Is secreted by hair cells |
Endolymph in inner ear:
A |
Is a filtrate of blood serum |
|
B |
Is secreted by striae vascularis |
|
C |
Is secreted by basilar membrane |
|
D |
Is secreted by hair cells |
The commonest genetic defect of inner ear causing deafness is:
A |
Michel aplasia |
|
B |
Mondini aplasia |
|
C |
Scheibe aplasia |
|
D |
Alexander aplasia |
The commonest genetic defect of inner ear causing deafness is:
A |
Michel aplasia |
|
B |
Mondini aplasia |
|
C |
Scheibe aplasia |
|
D |
Alexander aplasia |
What are the boundaries of Trauttmann’s triangle?
A |
Bony labyrinth anteriorly |
|
B |
Bony labyringh posteriorly |
|
C |
Sigmoid sinus posteriorly |
|
D |
a and c |
What are the boundaries of Trauttmann’s triangle?
A |
Bony labyrinth anteriorly |
|
B |
Bony labyringh posteriorly |
|
C |
Sigmoid sinus posteriorly |
|
D |
a and c |
Trautmann’s triangle is bounded by the bony labyrinth anteriorly, sigmoid sinus posteriorly and the dura or superior petrosal sinus superiorly
Not included in bony labyrinth:
A |
Cochlea |
|
B |
Semicircular canal |
|
C |
Organ of Corti |
|
D |
Vestibule |
Not included in bony labyrinth:
A |
Cochlea |
|
B |
Semicircular canal |
|
C |
Organ of Corti |
|
D |
Vestibule |
Endolymph in the inner ear:
A |
Is a filterate of blood serum |
|
B |
Is secreted by stria vascularis |
|
C |
Is secreted by basilar membrane |
|
D |
Is secreted by hair cells |
Endolymph in the inner ear:
A |
Is a filterate of blood serum |
|
B |
Is secreted by stria vascularis |
|
C |
Is secreted by basilar membrane |
|
D |
Is secreted by hair cells |
Fluctuating recurring variable sensorineural deafness is seen in:
A |
Serous otitis media |
|
B |
Heamotympanum |
|
C |
Perilabyrinthine fistula |
|
D |
Labrinthine concussion |
Fluctuating recurring variable sensorineural deafness is seen in:
A |
Serous otitis media |
|
B |
Heamotympanum |
|
C |
Perilabyrinthine fistula |
|
D |
Labrinthine concussion |
A 38-year-old male presented with a suspected diagnosis of suppurate labyrinthitis. A positive Rinne’s test and positive fistula test was recorded on initial examination. The patient refused treatment, and returned to the emergency department after 2 weeks complaining of deafness in the affected ear. On examination, fistula test was observed to be negative. What is the likely expected finding on repeating the Rinne test?
A |
True positive Rinne’s test |
|
B |
False positive Rinne’s test |
|
C |
True negative Rinne’s test |
|
D |
False negative Rinne’s test |
A 38-year-old male presented with a suspected diagnosis of suppurate labyrinthitis. A positive Rinne’s test and positive fistula test was recorded on initial examination. The patient refused treatment, and returned to the emergency department after 2 weeks complaining of deafness in the affected ear. On examination, fistula test was observed to be negative. What is the likely expected finding on repeating the Rinne test?
A |
True positive Rinne’s test |
|
B |
False positive Rinne’s test |
|
C |
True negative Rinne’s test |
|
D |
False negative Rinne’s test |
In severe SNHL: Rinne’s test is false negative and because labyrinth is dead. Fistula test is negative.
False negative Rinne test occurs in case of severe SNHL because patient does not perceive any sound of tuning fork by air conduction but responds to bone conduction due to intracranial transmission of sound from opposite healthy ear.
Fistula Test
The basis of this test is to induce nystagmus by producing pressure changes in the external canal which are then transmitted to the labyrinth. Stimulation of the labyrinth results in nystagmus and vertigo. Normally the test is negative because the pressure changes in the EAC cannot be transmitted to the labyrinth.
Positive Fistula Test is seen in:
- Erosion of horizontal semicircular canal (Cholesteatoma or fenestration operation)
- Abnormal opening in oval window (post stapedectomy fistula) or round window (rupture of round window).
- A positive fistula test also implies that the labyrinth is still functioning.
- False-negative fistula test: Dead labyrinth, cholesteatoma covering site of fistula.
- False-positive fistula test (Positive fistula test without Fistula): Congenital syphilis, 25% cases of Meniere’s disease (Hennebert’s sign.)
- OAE is considered as best screening test as it is less time consuming, easy to perform, child does not need to be sedated and results are available immediately
- Absent OAE indicates cochlear lesion.
- If OAE are absent child is taken up for BERA which is confirmatory.
On otological examination, all of the following will have positive fistula test except:
A |
Dead ear |
|
B |
Labyrinthine fistula |
|
C |
Hypermobile stapes footplate |
|
D |
Following fenestration surgery |
On otological examination, all of the following will have positive fistula test except:
A |
Dead ear |
|
B |
Labyrinthine fistula |
|
C |
Hypermobile stapes footplate |
|
D |
Following fenestration surgery |
A positive fistula test during Siegelisation indicates:
A |
Ossicular discontinuity |
|
B |
Para-labyrinthitis due to erosion of lateral semi-circular canal |
|
C |
CSF leak through the ear |
|
D |
Fixation of stapes bone |
A positive fistula test during Siegelisation indicates:
A |
Ossicular discontinuity |
|
B |
Para-labyrinthitis due to erosion of lateral semi-circular canal |
|
C |
CSF leak through the ear |
|
D |
Fixation of stapes bone |
Destruction of right labyrinth causes nystagmus to:
A |
Right side |
|
B |
Left side |
|
C |
Pendular nystagmus |
|
D |
No nystagmus |
Destruction of right labyrinth causes nystagmus to:
A |
Right side |
|
B |
Left side |
|
C |
Pendular nystagmus |
|
D |
No nystagmus |
- In destructive lesions eg. trauma to labyrinth, the nystagmus is towards the opposite side.
- In irritative lesions eg. serous labyrinthitis, fistula of labyrinth, the nystagmus is towards ipsilateral side.
Extracranial complications of CSOM:
A |
Labyrinthitis |
|
B |
Otitic hyrocephalus |
|
C |
Bezold’s abscess |
|
D |
a and c |
Extracranial complications of CSOM:
A |
Labyrinthitis |
|
B |
Otitic hyrocephalus |
|
C |
Bezold’s abscess |
|
D |
a and c |
Extra cranial complications of CSOM are:
- Petrositis (gradenigo syndrome)
- Labyrinthitis
- Osteomyelitis of temporal bone
- Septicemia / pyaemia
- Otogenic Tetanus.
- F. Facial nerve palsy
- Acute Mastoiditis: – Postaural sub periosteal abscess
– Zygomatic abscess
-Luc’s abscess
-Citelli abscess
– Bezold abscess
Most potential route for transmission of Meningitis from CNS to Inner ear is:
A |
Cochlear Aqueduct |
|
B |
Endolymphatic sac |
|
C |
Vestibular Aqueduct |
|
D |
Hyrtle fissure |
Most potential route for transmission of Meningitis from CNS to Inner ear is:
A |
Cochlear Aqueduct |
|
B |
Endolymphatic sac |
|
C |
Vestibular Aqueduct |
|
D |
Hyrtle fissure |
Cochlear aqueduct is a bony canal that connects the cochlea to the intracranial subrachnoid space.
Perilymph within the cochlear aqueduct is in direct continuation with the CSF and hence Cochlear Aqueduct is the most important route for meningitis to spread to the inner ear.
All are true about glomus jugulare tumors except:
A |
Common in female |
|
B |
Causes sensory neural deafness |
|
C |
It is a disease of infancy |
|
D |
It invades labyrinth, petrous pyramid and mastoid |
All are true about glomus jugulare tumors except:
A |
Common in female |
|
B |
Causes sensory neural deafness |
|
C |
It is a disease of infancy |
|
D |
It invades labyrinth, petrous pyramid and mastoid |
True regarding movements of the cilia in the inner ear are all except:
March 2009
A |
It moves when head is rotated |
|
B |
It moves when moving person suddenly stops |
|
C |
It moves when perilymph moves |
|
D |
Its movement is guided by the inertia of endolymph |
True regarding movements of the cilia in the inner ear are all except:
March 2009
A |
It moves when head is rotated |
|
B |
It moves when moving person suddenly stops |
|
C |
It moves when perilymph moves |
|
D |
Its movement is guided by the inertia of endolymph |
Ans. C: It moves when perilymph moves
Into the cupula are projected hundreds of cilia from hair cells located on the ampullary crest.
When the head suddenly begins to rotate in any direction (angular acceleration); the endolymph in the semicircular canals, because of its inertia, tend to remain stationary while the semicircular canals turn. This cause relative fluid flow in the ducts in the direction opposite to the head rotation.
Similarly When the rotation stops suddenly: the endolymph continues to rotate. And this time cupula bends in opposite direction, causing hair cells to stop discharging entirely.
Function of ossicles in middle ear is to _______
A |
Amplify intensity of sound |
|
B |
Protect from loud sound |
|
C |
Conduct sound energy from the tympanic membrane to the oval window and then to the inner ear fluid |
|
D |
None of the above |
Function of ossicles in middle ear is to _______
A |
Amplify intensity of sound |
|
B |
Protect from loud sound |
|
C |
Conduct sound energy from the tympanic membrane to the oval window and then to the inner ear fluid |
|
D |
None of the above |
The ossicles (auditory ossicles) are the three smallest bones in the body, the malleus, the incus, and the stapes.
They are contained within the middle ear space and serve to transmit sounds from the air to the fluid-filled labyrinth (cochlea).
Not a part of bony labyrinth‑
A |
Cochlea |
|
B |
Vestibule |
|
C |
Utricle |
|
D |
Semicircular canal |
Not a part of bony labyrinth‑
A |
Cochlea |
|
B |
Vestibule |
|
C |
Utricle |
|
D |
Semicircular canal |
The inner ear within the petrous part of temporal bone consists of a membranous labyrinth enclosed in a bony (osseous) labyrinth. So, inner ear has two parts : ‑
1) Bony labyrinth :- Cochlea, Vestibule, Semicircular canals.
2) Membranous labyrinth :- Cochlear duct, utricle, Saccules, three semicircular ducts, and endolymphatic duct & sac.
Bilateral Rinne test +ve and Weber test lateralized to right with a shortened Schwabach test on left side suggests ‑
A |
Left middle ear pathology |
|
B |
Right middle ear pathology |
|
C |
Left inner ear pathology |
|
D |
Right inner ear pathology |
Bilateral Rinne test +ve and Weber test lateralized to right with a shortened Schwabach test on left side suggests ‑
A |
Left middle ear pathology |
|
B |
Right middle ear pathology |
|
C |
Left inner ear pathology |
|
D |
Right inner ear pathology |
Ans. is ‘c’ i.e., Left inner ear pathology