short note on physiology and some clinical cases

1. Diseases of the inner ear
Dr. Rahman Aljanabi
FEB.ORL-HNS;CABMS;FJBMS
KUFA Medical College 2015

2. Introduction
Anatomy:
The inner ear consist of :
1-the cochlea : concerned with hearing
2-the vestibular apparatus : responsible for equilibrium
:
A-3 semicircular canals :
B- Utricle :
C- Sacule :

7. How the body maintain balance
.note 1:- normally, the impulses reaching the brain from three
systems(vestibular, visual and somatosensory) which are peripheral
sensory organ of position that send information to higher center which
will analyzed and integrated to maintain position(very complex
mechanism involving various reflex arcs and cerebellar and cerebral
control)
Note 2:- these impulses are equal and opposite so the brain can detect
any changes in position by relative difference in impulses between the
tow side
Note 3 :- there is central compensation for the lack of one of the
balance maintain mechanism but this is a time dependent process so
the more acute pathology the more patient symptoms and vice versa.

8. Symptoms of inner ear diseases:-
Cochlea :-----hearing loss(sensorineural), tinnitus
Vestibular system(SCC and vestibule):----vertigo or unsteadiness
Note 1:-peripheral vestibular system:-include the vestibular apparatus(SCC and
vestibule) and vestibular nerve
Central vestibular system(within CNS):starts from vestibular nuclei in the Pons
and its central connection(including cerebellum)
Note 2:- body balance is maintained by a complex mechanism involving input data from
vestibular, visual, and somatosensory (proprioception) systems that is transmitted to
higher center(cerebrum and cerebellum) to be analyzed and integrated to maintain
balance
Note 3:-there is central compensation for the lack of one of the balance maintain
mechanism but this is a time dependent process so the more acute pathology the more
patient symptoms and vice versa
e

9. Causes of peripheral vestibular system
Like any organ in the body, the vestibular system can be affect
by:-
A-Congenital malformation:-but it is a symptomatic as central
compensation occur early in infancy
B-acquired:-
1-infections:- bacterial or viral ;acute or chronic e.g labrynthitis ,
vestibular neuritis ,syphilis
2-tumour:-like acoustic neuroma(vestibular schwannoma)
3-trauma:-temporal bone fracture, perilymph fistula
4-Autoimmune:- autoimmune inner ear diseases
5-vascular:- labyrinthine apoplexy
6-degenerative:- Dysequilibrium of ageing (presbyastasis)
7-miscillaneous:- Meniere's disease, benign paroxysmal positional
vertigo(BPPV)

10. Vestibular disorders
Peripheral (Lesions of end
organs vestibular nerve)
• Meniere's disease
• Benign paroxysmal
positional vertigo
• Vestibular neuritis
• Labrynthitis
• Vestibulotoxic drugs
• Head trauma
• Perilymph fistula
• Syphilis
• Acoustic neuroma
Central (Lesions of brainstem
and central connections)
• Vertebrobasilar insufficiency
• Posterior inferior
cerebellar artery syndrome
• Basilar migraine
• Cerebellar disease
• Multiple sclerosis
• Tumors of brainstem and
fourth ventricle
• Cervical vertigo
Epilepsy

11. Benign Paroxysmal Positional vertigo(BPPV)
Its symptoms are repeated attacks(paroxysm) of rotation
sensation (vertigo) lasting for seconds caused by changes
in the position of the head(positional).
the patient is completely normal in between attacks
it is the most common cause of the symptoms of vertigo
usually associated with nausea and vomiting, no cochlear,
no CNS symptom(like loss of consciousness, paresthesia ,
weakness, cerebellar sign etc)

12. Pathophysiology of BPPV
BPPV is a mechanical problem in the
inner ear. It occurs when some of the
calcium carbonate crystals (otoconia)
that are normally embedded in the gel
layer of the macula of the utricle
become dislodged and migrate into one
or more of the 3 1SCC as it is most
dependant
This floating particle cause stimulation of
hair cells of crista of posterior SCC when
the head move then rapidly settle

16. BPPV
Examination:- nothing significant
Dx.:- by Dix-Hallpike maneuver(torsional nystagmus and
vertigo(after a latency of 3-10 sec. ,lasting less than 1 min. and
fatigue on repeating the test)
Cause:-idiopathic but otoconia may dislodge due previous head trauma or
aging process etc
Treatment:- repositioning the particles of otoconia in the utricle
instead of posterior SCC by different maneuver like Epply man. and
Semont man.
The condition usually resolve spontaneously within a week or few
weeks but tend to recur after a period of time

17. Dix-Hallpike test and Epply maneuver

18. Meniere’s disease
Is an inner ear disease
characterized by :-
Episodic vertigo ,hearing
loss ,tinnitus and ear
fullness lasting for
minutes –days.
The disease affect cochlea
and SCC and
vestibule(whole
membranous labyrinth)
which reflect its symptoms

19. Pathogenesis
Distension of the
membranous
labyrinth or
endolymphatic
hydrops is
postulated as a
cause of this
condition either
due to excessive
production or
impair absorption
of endolymph

20. Meniere’s disease
 The attack
occurs due to
small ruptures
in Reissner
membrane
leading to
mixing of the
endolymph
and perilymph
.

21. Meniere’s disease
 Clinical features
 The duration of the vertigo last usually for 30 minutes
to 4 hours
 The vertigo is often disabling and very acute in onset
 Associated with nausea and vomiting
 The patient feels tired for the next few days
after the attack.

22. Meniere's disease
2- hearing loss is sensorineural in type and in early stage
of the disease affects the lower frequencies and return
to normal after the attack (fluctuating hearing loss )
3-Tinnitus and a feeling of fullness or pressure in the
affected ear may precedes the attack

23.  Over the course of the disease hearing loss and
tinnitus become permanent
The disease is usually unilateral initially but can become
bilateral
Sign:- spontaneous rotatory nystagmus
Investigations:- P.T.A. , brain MRI may be needed to role
out central causes

24. Meniere's ‘s disease
Treatment:-
 In acute phase :- treatment consists of vestibular
sedative(stugerone, anti-emetics),
Betahistine(betaserc) ,diuretics
 In long term :-avoidance of caffeine and salt and
reassurance can reduce the number of the attacks and
increase the patient ability to cope with the attacks

25. Meniere’s disease
Ablation therapy:-
Gentamycin is given through the tympanic membrane
will be absorbed through the round window and
selectively damage the vestibular cells relative to the
cochlear cells

26. Meniere’s disease
2-Surgical Treatment:- rarely needed
A. Endolymphatic sac surgery:
By transmastoid approachch the endolymaphatic
sac either decompressed or a shunt is placed in the sac
that communicates with the subarachnoid space or
mastoid cavity
B-Vestibular nerve section:- in patients with
serviceable hearing
C-labyrinthectomy : - in patients with unilateral
Meniere’s disease and poor hearing
y.

27. Vestibular neuritis
Is a viral infection of the vestibular nerve

28. Vestibular neuritis
Etiology:- most likely due to viral infection supported by polymerase chain
reaction to detect viral DNA In postmortem study mostly Herpes simplex virus
type one
Symptoms:- acute spontaneous vertigo associated with nausea and vomiting
lasting from days –weeks, no cochlear involvement, no CNS The symptoms
subside over the following days but many patients have residual imbalance
that last for months .
Hearing is normal
Sign:-
Acute attack there is nystagmus (horizontal towards the unaffected side )
After acute stage passed, nystagmus disappear but patient characteristically rotate
towards the affected side when attempt to march on a spot with their eyes
closed positive Unterberger test

29. Vestibular neuritis
Ix:- PTA ,brain MRI may be needed if central vertigo can
not be excluded easily
Treatment :- acute stage:-bed rest , vestibular sedative ,
steroids can be used to shorten the course of the disease
Antiviral??
Resolution stage:-after vertigo subsides (vestibular rehabilitation
exercise) will enhance central compensation(as it is a paretic
pathology)

30. Traumatic inner ear
disease(Temporal bone fractures
20 % of skull base fractures
Etiology :
1-RTA
2-Blunt trauma to the lateral surface of the
skull
Classification :
1-longitudinal fractures 80 -90 %
2-transverse fractures 10- 20%

31. 1-longitudinal fractures

32. transverse fractures

33. Longitudinal fracture
 Usually spare the labyrinth and facial nerve
 The fracture line involves the external meatus and the roof of
the of the middle ear . Bleeding in the middle
ear(heamotympanum) ,ossicular chain disruption, tympanic
membrane may be perforated
 Bloody otorrhea (even CSF )occur if TM is perforated and
 Deafness usually conductive type
 Facial palsy is uncommon
 Battle’s sign :ecchymosis in the postauricular area


34. Battle sign Haemotympanum

35. Transverse fracture
Transverse fracture usually involve the
labyrinth and thus lead to
sensorineural hearing loss with
profound vertigo .
This vertigo will settle with time as
central compensation occurs .
Facial palsy occurs in 50 % of cases .

36. Treatment
Management:- multitrauma patient with head trauma
For fracture itself--conservative plus broad spectrum
antibiotic
Vertigo---vestibular sedative
Haemotympanum----conservative treatment usually
resolves within 3-4 weeks
Tympanic membrane perforation----usually heals within 3
months if persists then myringoplasty

37. Treatment
3-Facial nerve paralysis:
a- Immediate paralysis treated by surgical
exploration with attempt to repair the nerve.
B- Delayed paralysis : usually treated
conservatively
4- CSF leak :
A- medical treatment : bed rest ,head elevation ,
stool softener , lumbar drain and antibiotics to
prevent meningitis
B- surgical closure of the defect if medical treatment
fail

38. Acoustic trauma :
 Acute acoustic trauma may arise from
sudden very loud sound as in explosion
 The effects
 Sensorineural hearing loss (most common )
 Conductive deafness due to tympanic
membrane rupture or damage to the middle
ear .

39. Noise induced hearing loss
Chronic noise induced hearing loss
results fro long term exposure to loud
sounds
As in heavy industry workers
Tinnitus is a prominent feature in this
condition and the audiogram has a
classical appearance with a dip at 4 khz
.