Download Tinnitus

Tinnitus: A warning
symptom in non
otological pathologies
Amr El Refaie, MD
Auckland 2014
What is Tinnitus?
• A family of symptoms rather than a
disease
• Symptoms belong to a varying number of
pathologies
The sensation of sound/noise, not brought
about by simultaneously applied mechanoacoustic or electrical signal
Tinnitus management?
•Tinnitus is a symptom
waiting for a diagnosis
(first)
If I am attending a patient with
tinnitus
• What are the causes? Sinister
pathology?
• How does it work? Can I affect the
generation mechanisms?
• What are the effects? Can I improve the
quality of life?
Tinnitus and non otological
conditions
• The list is long !!
• Somatosensory tinnitus and TMJ
dysfunctions
• Demyelination related tinnitus
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The concept of cross modal
interaction of multisensory
neurones
• The responsiveness of a single neuron to
stimulation of different sensory modalities
and/or the modulation of activity evoked by
one modality on that evoked by another
(Kayser & Logothetis, 2007)
• Changes in the response rate of the
neuron, being either suppressive or
enhancing
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Hypothesis
• it has been suggested that proprioceptive
inputs from intra oral structures could be
used to cancel responses to auditory
stimuli evoked by internally generated
sounds as self vocalization and respiration
(Bell et al., 1997; Shore, 2005)
• The functioning of the DCN in detection
and processing external auditory signals
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Implications
• “Referred” tinnitus from areas supplied by
the trigiminal nerve (dental region)
• Similar mechanisms working for the facial
nerve, vagus nerve, great auricular nerve
• Especially important in cases of unilateral
acute tinnitus, intermittent tinnitus,
pulsatile tinnitus (Somatosensory pulsatile
tinnitus syndrome, Levine et al, 2008)
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TMJ and tinnitus
• Temporo-mandibular pain-dysfunction
syndrome, Cranio-mandibular disorder,
Costen’s syndrome
• A syndrome of joint crepitus, joint locking,
tinnitus, aural congestion/fullness, vertigo,
hyper- or hypoacusis, blurred vision,
hoarseness and orofacial dysaesthesia
(Chan and Reade, 1994)
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Signs
• tenderness of the temporomandibular
joint(s) on lateral and posterior palpation
• Deviation and limitation of the mandible on
jaw opening and on lateral excursions with
or without joint noises
• Tenderness associated with the palpation
of the muscles of mastication including the
masseter, medial pterygoid, and
temporalis muscles
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Prevalence of otological
complaints in TMJ disorders
• 60% of patients with chronic tinnitus has
one or two TMJ symptoms, in relation to
36% of non tinnitus control group
(Bernhardt et al, 2004)
• Incidence of 7% in 900 patients series (
Upton et al, 2004)
• 80% of patients had TMJ symptoms, 43%
improved after treatment for TMJ(Tullberg
and Ernberg, 2006)
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Pathophysiology
• Muscular spam/anatomical theory
• Cross modulation/neurological theory
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Muscular spasm/anatomical
theory
• Mandibular over closure with posterior
dysplacement of the condyle, pressuring
the Auriculotemporal and chroda tympani
nerves, and the ET
• Tympanic plate and glenoid fossa erosion
(Costen 1956)
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Functional/muscular recruitment
• Spasm of the masseters, posterior
ptyregoid muscles in particular transmitted
to muscles and structures of the middle
ear
• Internal ptyregoid muscles connection to
the tensor tympani muscles, tensor veli
palatini muscles
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Functional/muscular recruitment
• Facial spasm and non acoustic stapedius
muscle contraction
• Masseter muscle spasm and contraction
of the stapedius muscle (stapedius muscle
lying within the pain reference zone of the
messeteric trigger points) Travell and
Simmons, 1983
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Alteration of acoustic
transmission
• Tremor or myoclonus of the tensor
muscles in the middle ear (myorhythmia)
caused by ‘autogenous vibrations’ in the
sound conducting system.
• This was thought to be the result of a
fatigue reaction resulting from prolonged
irritation and stress of the muscles
innervated by the trigeminal nerve
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Embryological attributes
• The malleus, incus, anterior malleolar
folds, and the tensor tympani and tensor
veli palatini muscles are all derived from
the first pharyngeal arch and hence are
innervated by the trigeminal nerve
• Same as the masticatory and tensor
muscles of the jaw
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Neurological correlates
• Cross-modulation and referred signals
• Synkenesis, masseter and tensor tympani
cross innervation(mainly post traumatic)
• Impacted third molar tooth, with
subsequent infection and pressure
• Sensory signal from the trigeminal nerve
could be affected during tooth-grinding
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Management of TMJ pain
dysfunction syndrome
• Counselling, biofeedback, thermotherapy
• Acupuncture, cryotherapy, ultrasound
therapy
• Intra-articular injection, corticosteroids,
analgesics, muscle relaxants
• Surgery, prosthetic rehabilitation,
interocclusal appliance therapy
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Demyelination
• Demyelination refers to a group of
neurological conditions characterised by
the loss of the myelin sheath insulation of
the nerves
• Multiple sclerosis (MS) is the most
common pathological entity, other
conditions include Guillian-Barre
syndrome, Transverse myelitis, some
manifestations of pernicious anaemia,…
Multiple Sclerosis (MS)
• Demyelination is the root cause of the symptoms
that people with MS experience. When it occurs
the speed at which messages pass along the
nerves is slower than normal. Even when the
patches of scarring caused by demyelination
have healed and re-myelination has occurred,
the response time of the nerve endings tends to
remain slower.
Aetiological theories
• Immunologic:
– Specific immune response directed against
the CNS
– Evidences are emerging about specific
antigens and receptors sites, still some way to
go
– The destruction of the myelin sheath and
nerve fibres lead to slowing down and
disruption of neural transmission
Aetiological theories
• Environmental
– Migration patterns and epidemiological
studies have shown that people who migrate
from a high risk geographical areas of
contracting MS, to low risk areas before the
age of 15, acquire the new risk criteria of their
new home
– Higher risk the farther you are from the
equator? Sun exposure and vitamin D role?
Aetiological theories
• Infectious agent
– Many viruses and bacteria, especially those
with higher risk of exposure during childhood,
are known to trigger an inflammatory reaction
which might be the precursor for demylination
– EB virus, measles, human herpes-6,
Chalmydia penumonia have all been
implicated but strong evidences are yet to be
revealed
Aetiological theories
• Genetic:
– Not strictly hereditary, but having a first class
relative with MS increase the risk of
developing the condition several times above
the population average
– Theories are developing about genetic
predisposition to environmental factors,
leading to a certain autoimmune response,
possibly triggered by an inflammatory
process, are developing
Multiple Sclerosis (MS)
• MS is a progressive disease of the nervous system, for which there
is no cure, yet.
• An estimated 2,500,000 people in the world have MS.
• More women than men have MS, with a ratio of 2 men to 3 women
affected.
• MS is the most common diseases of the central nervous system in
young adults.
• Diagnosis of MS occur generally between 20-40 years of age, very
rarely before 12 or after 55
Multiple Sclerosis (MS)
• There are four types of MS:
-
Relapsing – remitting (RR):
-
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Primary – progressive (PP):
-
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About 50% of RR individuals will develop within 10 years
Progressive – relapsing (PR):
-
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10-20% from the beginning
Secondary – progressive (SP):
-
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Most common type, 65-80% of patients at the beginning
Steady decline in abilities accompanied by sporadic attacks
Malignant (Fulminant, Marburg variant)
-
Very rare extremely rapid deterioration
Common symptoms
- Visual disturbances
- Limb weakness, involuntary muscular
spasms
– Loss of sensations, altered sensations,
anywhere
– Speech impediments
– Depressions, mania, paranoid state,..
Hearing loss, tinnitus and MS
• Up to 3% of patients complain of hearing
loss and tinnitus
• More likely to occur during the first 4 years
and can be the presenting symptom
• Cases presenting with unilateral and
bilateral sudden SNHL and tinnitus have
been reported (Drulovic et al, 1993,
Schweitzer et al, 1989)
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Hearing loss, tinnitus and MS
• Tinnitus can precede, follow or occur
independent of HL
• Pontine hearing loss with loss of ABR
waves after wave III (Morgen and Kau,
1988)
• Cortical hearing loss
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Vertigo and dizziness
• Vertigo and dizziness are common at some
point in the natural history of the disease (up
to 25% at some stage of the disease, John
Booth, 1996)
• Vertigo is the initial presentation symptom in 5%
of cases (McAlpine et al,1972), can be
accompanied by tinnitus
• Blurring/loss of visual acuity and optic nerve
neuritis are the presenting symptom in 20% of
cases
ENG/VNG manifestations
• Derangement of saccadic and smooth pursuit
eye movement
• Spontaneous nystagmus (peripheral or central)
• Positional nystagmus
• Dissociated nystagmus
• Direction-changing nystagmus
• Derangement of optokinetic nystagmus
(reversal?)
• Vertical upbeat nystagmus
Case study
• 22 male presented to the clinic with:
– Vertiginous attacks or rotatory vertigo
– Mild loss of hearing in the right ear
– No other symptoms
– Right mild to moderate SNHL with excellent speech
discrimination
– Left beating spontaneous nystagmus, third degree, peripheral
characteristics
– Mild derangement of saccades but within tolerance
– No significant delay in ABR
Investigations
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History
Audiological evaluation
Evoked potentials
Electronystagmography/VNG
Optic examination (Fundus examination)
MRI Scan and radiological investigations
Lumbar puncture
Management
• Improving the speed of recovery from
attacks (corticosteroids)
• Attempting to slow the progression of the
disease (Disease Modifying Drugs, DMD)
• Treating the physical manifestations of the
condition
• The role of interferon (beta 1-b)
Alemtuzumab
• A drug usually used in treatment of Leukaemia
• It works by destroying the immune system of the
patient, especially the B &T lymphocytes
• It forces the immune system to produce new
cells that might not attack the nervous system
• Early encouraging results (Coles et al,
Cambridge university, 2012) especially in
relapsing remitting type (side effects too)
Future directions in management
• Surgery?
• Stem cell therapy?
• Improving signal transmission in injured
cells?
• Preventing demylenation/cell death?
Research threads
• Incidence of early presentation of
otological symptoms in specific
populations (stage of ethical application)
• Audio-vestibular manifestations in MS
patients. Different problems in different
types/stages?
• Effect for early intervention, longitudinal
study
The role of the Audiologist
• Main theme is that Early diagnosis and
intervention = improved chance of better
quality of life for longer time (RR for longer
periods, with longer remissions)
• All clinicians must have the knowledge
and ability to “suspect”
• Increase the incidence of suspicion
How do we suspect?
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Age
Vertigo/Hearing?
Associated symptoms?
Change in acuity of vision
Fatigue
Neurological manifestations