According to the information in the
case history, this patient will be given the diagnosis of Meniere’s disease (stage
3) associated with posterior canal Benign Paroxysmal Positional Vertigo
(BPPV)in the right ear. We gave her this diagnosis for the following reasons:
Meniere’s diagnosis: During the last
24 months she reports four episodes of drop in hearing on the right side,
associated right sided tinnitus, and aural fullness. She also reports rotatory
vertigo, lasting from 2-6 hours. Also, we estimated that she has stage 3 of
Meniere’s disease because she reported that is since
the last attack 3 months ago, her hearing loss has persisted and not feel stable
in the dark, which are hall marks in the stage 3.
BPPV diagnosis: In the last 6 weeks
she reports a new symptom of short lived rotatory vertigo on turning to her
right side in bed, and looking up. This occurs most times she makes these
v Tests and results:
ü For Meniere’s disease diagnosis we can perform the following tests:
Ø Audiologic tests
§ Pure tone audiometry: Due to her diagnosis of stage 3 the results
will show flattening sensorineural hearing loss in the right ear.
§ Speech audiometry: The result will revel reduced
or possibly worsening speech discrimination.
§ Otoacoustic emissions(OAE): The result will
revel lowered main frequencies, the frequency of emission may provide
§ Brainstem-evoked auditory responses(BEAR): The result will revel
normal, shorter or delayed wave 5 latency in the right ear.
§ Traveling-wave velocity(TWV): The result will revel faster
traveling waves (masked wave 5 latency difference b0.6 ms).
§ Low-frequency masking(LFM): The result will revel absent phase
dependence of masking, reduced modulation depth of audiometric threshold (b28
dB) and impaired masking of BEAR.
§ Immittance tests: The result will revel increased conductance
width, decreased resonance frequency and lowered threshold of the cochleostapedial
§ Electrocochleography (ECoG): The test measures the electrical
potentials produced in the inner ear in response to sound. It will record a
large waveform, which results from providing sound stimulation to the inner
ear. This waveform contains two components, the summating potential (SP) and
the action potential (AP). The summating potentials reflect the cochlear
bioelectric activity, while the action potentials reflect the activity of
distal afferent fibers of the 8th nerve. ECoG results for MD will show enhanced
negative SP, enlarged SP/AP ratio (N0.34), increased AP/N1 latency difference
to clicks of opposing polarity (N0.38 ms), increased SP/AP area curve ratio
(N1.34), and increased SP/AP width (N1.89).
(N1 means first
negative peak of the ECoG recording).
Ø Vestibular tests
§ Instrumental-aided study of nystagmus (e.g., by electronystagmography
and rotatory chair protocols): Often spontaneous nystagmus toward the
unaffected ear and canal paresis of the affected ear, occasionally vestibular
hyperactivity of the affected ear.
§ Vestibular-evoked myogenic potentials (VEMP): Measures the
sternocleidomastoid muscle contraction in response to loud sound. It also
measuring the otolith (saccule and utricle) function and both branches of the
vestibular nerve and the vestibulospinal tract. VEMP results for MD will show decreased
or absent amplitude in the infected ear.
§ Computed tomography(CT): The result will revel narrower, shorter,
or nonvisualized vestibular aqueduct, smaller external aperture, and abnormally
decreased periaqueductal pneumatization.
§ Magnetic resonance(MR): The result will revel narrowed
endolymphatic duct, obstructed endolymphatic sac, direct visualization of the
ü For the diagnosis of posterior BPPV we can perform the Side Lying
manoeuvre not the Dix– Side lying test
will show that in first 2-3 seconds there is no nystagmus. Then up-ward
vertical nystagmus (with torsional component towards the downward ear). Then
reversal of nystagmus upon sitting.
Also, the Videonystagmograghy (VNG) can use to diagnose the
posterior BPPV and the estimate results will be as the same as the positive
Side Lying test. However, the Electronystagmography (ENG) and the Caloric test
can’t be used in the diagnosis of the posterior BPPV because they can’t
diagnose the torsional nystagmus that result from this disease. In addition,
VEMP test can be used in the diagnosis of BPPV and the result will show reduced
or absent amplitude at the infected side and delayed peak latency (P13 or N1).