Facial NerveFacial Nerve1 emerges from the pons 1 emerges from the pons 2 CPA (2 CPA (cerebello-pontine angle)cerebello-pontine angle)3 internal auditory meatus. 3 internal auditory meatus. 4 medial wall of tympanic 4 medial wall of tympanic

cavity.cavity.5 bends backwards at right 5 bends backwards at right angle where the geniculate angle where the geniculate

ganglion is situatedganglion is situated6 Passes horizontally, 6 Passes horizontally,

enclosed in fallopian canal, enclosed in fallopian canal, above Oval window. above Oval window.

7 When it reaches the aditus it 7 When it reaches the aditus it turns downwards behind the turns downwards behind the pyramid and continues pyramid and continues

vertically till it merges fromvertically till it merges from8 stylomastoid foramen.8 stylomastoid foramen.

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Physiology of HearingPhysiology of HearingSound has two subjective physical Sound has two subjective physical

propertiesproperties

► FrequencyFrequency (pitch) : hertz (Hz) (pitch) : hertz (Hz) [Hz [Hz - - Cycle/sec] Cycle/sec]

► IntensityIntensity (loudness) : decibel (dB)(loudness) : decibel (dB)

Intensity

How We Hear How We Hear SoundsSounds??

Sound is collected by Sound is collected by the pinna and the pinna and directed into the directed into the outer ear canal.outer ear canal.

Sound makes the Sound makes the eardrum to vibrate.eardrum to vibrate.

Vibration causes three Vibration causes three ossicles to vibrateossicles to vibrate

Vibration setup in the Vibration setup in the endolymph and endolymph and perilymph. perilymph.

Vibration is Vibration is transferred to the transferred to the snail-shaped snail-shaped cochlea in the inner cochlea in the inner ear.ear.

Cochlea is lined with Cochlea is lined with sensitive sensitive hair cellshair cells (cilia) which move (cilia) which move when vibrated and when vibrated and cause a nerve cause a nerve impulse to form.impulse to form.

Unfolded cochlea

These impulses travel from cochlea through the cochlear division of vestibulocochlear nerve (8th cranial n.) to the brain.

Transformer RatioTransformer Ratio::

StapesTMSURFACEAREA

OSSICULARLEVERRATIO

Physiology of the Vestibular Physiology of the Vestibular ApparatusApparatus

Balance of the body is Balance of the body is maintained by maintained by coordination of coordination of information from three information from three systems:systems:

1.1. Vision.Vision.2.2. Proprioception, i.e. Proprioception, i.e.

sensation from sensation from muscles, joints, muscles, joints, tendons and tendons and ligaments.ligaments.

3.3. Vestibular system.Vestibular system.

Vestibular SystemVestibular System

►Semicircular canalsSemicircular canals►Utricle and saccule.Utricle and saccule.

Utricle and sacculeUtricle and sacculeRespond to Respond to linear accelerationlinear acceleration. .

Impulses from the utricle and Impulses from the utricle and saccule give information saccule give information about about position of the headposition of the head in in spacespace

Initiate reflexes which tend to Initiate reflexes which tend to keep the head in upright keep the head in upright positionposition

Semicircular Semicircular canalscanalsrespond to respond to angular (rotatory) angular (rotatory)

accelerationaccelerationSCC lie at right angles to SCC lie at right angles to

each othereach otherAny rotatory movement will Any rotatory movement will

stimulate at least stimulate at least one pair one pair of SCC(R+L).of SCC(R+L).

Movement of fluid within Movement of fluid within SCC will initiates a nerve SCC will initiates a nerve impulse to travel through impulse to travel through vestibular nerve. vestibular nerve.

Sensation of rotationSensation of rotation

Symptoms of ear diseaseSymptoms of ear disease1/ Hearing loss ( Deafness)1/ Hearing loss ( Deafness) Is defined as subjective impairment Is defined as subjective impairment

of hearing.of hearing. Three types;Three types; * conductive* conductive * sensorineural* sensorineural * mixed* mixed

C H L S N H L

Conductive Hearing Loss

Sound appears quieter but it is not distorted.

Sounds are well heard when amplified.

Paracusis Willisii positive especially otosclerosis

The quality of speech is well maintained.

Tinnitus usually absent

Sensorineural Hearing Loss

Sound quieter and distorted.

Sounds ' distortion limits the benefit of amplification .

Paracusis Willisii negative.

In severe cases speechbecomes indistinct and expressionless because patientdoes not hear his own voice.

Tinnitus present

C H L

• External canal obstruction: cerumen, F.B. polyp, atresia.• Perforated eardrum: otitis media, trauma, cholesteatoma• Ossicular chain fixation: otosclerosis, tympanosclerosis• Ossicular chain discontinuity car accident, head injury…• Fluid in middle ear : secretory otitis media (the most common cause in children)• Neoplasm of middle ear

SNHL

• Congenital hearing loss• Ototoxic Drugs• Aging:(Presbycusis)• Infection Cochlear: viral Retrocochlear: meningitis• Trauma fracture of base of skull • Tumor: cerebellopontine angle tumor vestibular schwannoma • Endolymphatic hydrops: Meniere's disease • Noise-induced hearing loss• Acoustic trauma

2/ Discharge( Otorrhea)2/ Discharge( Otorrhea)

1. Serous or purulent discharge1. Serous or purulent discharge Otitis externa.Otitis externa. 2. Mucopurulent discharge, foul smell 2. Mucopurulent discharge, foul smell

long duration:long duration: chronic suppurative otitis media.chronic suppurative otitis media.

3. Unilateral watery discharge following 3. Unilateral watery discharge following head injury or aural surgery: head injury or aural surgery:

CSF otorrhea. CSF otorrhea. (Damage to tegmen tympani)(Damage to tegmen tympani)

4. Bloody discharge; due to granulation 4. Bloody discharge; due to granulation tissue in chronic suppurative otitis tissue in chronic suppurative otitis media or due to malignant disease.media or due to malignant disease.

3. Pain (Otalgia)3. Pain (Otalgia)

Otogenic orOtogenic or primaryprimary

Non- otogenic or referred Non- otogenic or referred otalgiaotalgia

OtogenicOtogenic

A.A. External auditory canalExternal auditory canal► trauma (e.g. from trauma (e.g. from

cottoncotton bud abuse)bud abuse)► auricular haematomaauricular haematoma► foreign bodyforeign body► otitis externaotitis externa► EAC tumourEAC tumour

B.B. Middle earMiddle ear► acute otitis mediaacute otitis media► bullous myringitisbullous myringitis► chronic suppurativechronic suppurative

otitis media otitis media► middle ear tumourmiddle ear tumour

Referred OtalgiaReferred Otalgia

- OropharynxOropharynx (IXth nerve): (IXth nerve): ■■ tonsillitistonsillitis ■■ post-tonsillectomypost-tonsillectomy ■■ carcinoma posterior1/3carcinoma posterior1/3- LaryngopharynxLaryngopharynx (Xth nerve): (Xth nerve):

■■ pyriform fossa tumorpyriform fossa tumor

-- Upper molar Upper molar teeth,TMJ,parotid glandteeth,TMJ,parotid gland : : impacted wisdom teethimpacted wisdom teeth

new denturenew denture-- Cervical spineCervical spine (C2, (C2, C3)C3) pain is often worse at nightpain is often worse at night

4. Tinnitus4. Tinnitus ■ ■Is a Is a subjectivesubjective sensation of sound in the ear or head sensation of sound in the ear or head

in the absence of any relevant external signals. in the absence of any relevant external signals. (Occasionally it is (Occasionally it is objectiveobjective e.g. in palatal myoclonus and glomus e.g. in palatal myoclonus and glomus tumors).tumors).

■■ SSign of irritation of the cochlea or upper auditory ign of irritation of the cochlea or upper auditory pathways pathways

■ ■ … … Ear disease Ear disease ■■ … …It is a common symptom of anaemia, It is a common symptom of anaemia,

thyrotoxicosis, hyperdynamic circulation, thyrotoxicosis, hyperdynamic circulation, renal failure and some intracranial renal failure and some intracranial tumors. It may be caused by ototoxic tumors. It may be caused by ototoxic drugs, such as quinine, salicylates and drugs, such as quinine, salicylates and aminoglycocide.aminoglycocide.

5. Vertigo Is defined as hallucination of

movement or subjective sense of imbalance.

It can be due to CVS disease, CNS disease or ear disease.

Vertigo is considered as a symptom of irritation of the vestibular apparatus.

Vertigo may be central in origin (cerebellum), or peripheral (labyrinth /vestibular nerve). ►Peripheral lesions : intense vertigo of sudden onset. Nausea and vomiting ►Central lesions : less intense vertigo Positional changes have less effect, but the patient tends to have more disturbance of gait.

Congenital AbnormalityCongenital Abnormality

1. Preauricular sinuses 1. Preauricular sinuses and cysts.and cysts.

2. Anotia: Complete 2. Anotia: Complete absence of the pinna.absence of the pinna.

3. Microtia: Small pinna.3. Microtia: Small pinna.4. Accessory auricles.4. Accessory auricles.5. Atresia of the 5. Atresia of the

external auditory external auditory meatus.meatus.

6. Protruding ear (Bat 6. Protruding ear (Bat ear).ear).

Haematoma of the auricle Haematoma of the auricle (Haematoma auris)

extravasations of blood under the perichondrium leading to bluish swelling of the auricle.The ear may be slightly tender with a feeling of heat and discomfort.If untreated, the pinna may become distorted and thickened due to replacement of necrosed cartilage with fibrous tissue. A "cauliflower ear" – often seen in wrestlers- may result.

Haematoma of the auricle Haematoma of the auricle (Haematoma auris)

►Treatment►Aspiration or incision and drainage

under aseptic precautions followed by firm dressing or suturing of silastic sheets on pinna.

SymptomsSymptoms- HistoryHistory- Hearing loss if the FB Hearing loss if the FB

obstructs the canalobstructs the canal- Severe irritation and Severe irritation and

noise in the ear with noise in the ear with animate FBanimate FB

Signs:Signs:The FB can be seen by The FB can be seen by

otoscopyotoscopy

Foreign Bodies in the Ear

33 . .Foreign BodyForeign Body in The Earin The Ear

Type of patientType of patient::Commonly childrenCommonly children

Mentally retaded adultMentally retaded adultType of FBType of FB::

Animate FBAnimate FB:: Flies, larvae, fleas mosquitoFlies, larvae, fleas mosquito ,, ,,

Inanimate FBInanimate FB::Non vegitableNon vegitable: bead, button, : bead, button,

disc batterydisc batteryVegetable:Vegetable: bean and pea bean and pea

Types:Types:►Animate FB (flies and larvae)►Inanimate FB: vegetable : peas, beans non-vegetable : as buttons and disc battery

TreatmentTreatment::Animate FB: Animate FB: Kill by alcohol Kill by alcohol

remove by ear wash or remove by ear wash or crocodile forceps.crocodile forceps.

Inanimate FBInanimate FB::- - Non vegetableNon vegetable:: remove by ear remove by ear

wash or instruments wash or instruments BUT BUT PLEASE DO NOT WASH IF PLEASE DO NOT WASH IF THE FB IS DISC BATTERYTHE FB IS DISC BATTERY

- - VegetableVegetable: : Remove by Remove by instruments and avoid ear instruments and avoid ear wash because it may swell by wash because it may swell by water and become more water and become more impactedimpacted

General anesthesia may be General anesthesia may be needed in impacted FB and needed in impacted FB and uncooperative childrenuncooperative children

Complications:Complications:Injury of the external canal or Injury of the external canal or

drum by the FB or during drum by the FB or during removalremoval

So donn’t wash if:-The FB is vegetable -The FB is disc battery