Diseases of Inner ear الدكتور سعد يونس سليمان بسم الله الرحمن الرحيم Diseases of Inner ear الدكتور سعد يونس سليمان

Lecture Objectives Deafness (Hearing loss) Hearing Aids Otosclerosis (Otospongiosis) Sudden Sensorineural Hearing Loss Drug ototoxicity Presbycusis (Senile hearing loss) Deafness and Noise Non-Organic Hearing Loss Tinnitus

Deafness (Hearing loss) Conductive Congenital Acquired EAM ME Otic capsule SNHL Cochlear Retrocochlear

Hearing Aids A hearing aid is an electro-acoustic device used to amplify sounds. Design The basic components of any hearing aid are: Receiver ( microphone) Amplifier Sound transmitter (Ear phone) Power supply

Types of hearing aid Behind-The-Ear (BTE) In-The-Ear and In-The-Canal Aids: Body-worn aids Bone conduction HA: sound is transmitted from a vibrator that fit on mastoid bone

Bone-anchored hearing aids (BAHA)

Cochlear implant: an electronic device that can provide useful hearing for persons who have severe SNHL who cannot benefit from HA. It is composed of: 1- External component: which consist an external speech processor and transmitter. 2- Internal component: is surgically implanted and comprises the receiver / stimulator package with an electrode array.

OTOSCLEROSIS

DEFINITION Is hereditary localized disease of the otic capsule in which new spongy bone cause ankylosis of the foot plate of stapes leading to conductive deafness. Cochlear involvement with SNHL may also occur.

HISTOPATHOLOGY Resorption of bone by osteocytes Formation of new vascular spongy bone

Fissula ante fenestram (80% to 90%) AREAS OF PREDILECTION Fissula ante fenestram (80% to 90%)

COCHLEAR INVOLVEMENT

AETIOLOGY Hereditary factors: (50%) / autosomal dominant pattern with incomplete penetration. Racial distribution: white races (Caucasian) > coloured. Age: 15-45 years of age. Sex: females: male= 2:1. Pregnancy: may accelerate the condition but NEVER cause it.

CLINICAL PRESENTATION Hearing loss of gradual onset at 15 - 45 years Slowly progressive course 80% are bilateral Accelerates with pregnancy (30-40%) Tinnitus (75%) Paracusis Willisii Change of the speech pattern

PHYSICAL EXAMINATION Normal tympanic membrane Schwartze sign (Flamingo flush) * seen through the membrane due to hyperaemia of the promontory * indicates rapid progression of the disease. Tuning fork tests

PURE TONE AUDIOMETRY Conducive deafness. Carhart’s notch: is an increase in bone conduction threshold with a peak at 2,000 Hz. Explanation is not known Reverses following successful surgery In advanced cases there may be SNHL

Treatment Hearing aids Medical: sodium fluoride?! Surgical: stapedectomy which is total or partial removal of the foot plate of the stapes and replacement by prosthesis. Complication: perilymph fistula which is characterized by sudden SNHL and vertigo. It is liable to occur after sudden changes of pressure, so the patient should avoid diving and only fly in pressurized aircrafts.

Sudden Sensorineural Hearing Loss Aetiology Idiopathic: in 2/3 of cases Vascular: spasm, thrombosis or haemorrhage of the internal auditory artery. Viral infection: mumps, measles, rubella or Herpes zoster. Head injury with temporal bone fracture, blast injury, and ear surgery as stapedectomy. Tumors: acoustic neuroma.

Clinical Picture Hearing Loss Tinnitus: 80% --a good prognostic sign and means that hair cell still functioning. Vertigo: is common in those with vascular aetiology and caries a bad prognosis. Examination The TM is usual normal. Tuning fork test PTA: hearing loss in high frequency.

Treatment Prognosis Bed rest and sedation. Steroids in tapering dose. Vasodilators: Betahistine (Betaserc). Low molecular weight dextran Prognosis In 1/3 quick recovery. If there is no recovery within 3 weeks it is unlikely to occur spontaneously. In 1/3  partial recovery In 1/3 have none. Unfavorable prognostic features are severe HL and vertigo

Drug ototoxicity Damage to the cochlear and/or vestibular part of the inner ear by certain drugs. Ototoxic drugs include: Aminoglycosides Loop diuretics Salicylates. Quinine. Antiepileptics; phenytoin. B-blockers. Cytotoxic; cisplatin. Synergistic effect…. The dangers are especially great if excretion is impaired as in renal failure.

Presbycusis (Senile hearing loss) A symmetrical, progressive, bilateral SNHL age > 65 years no underlying cause. The degenerative changes occur as a result of aging process and vascular insufficiency Treatment Lip reading Hearing aids

Deafness and Noise Excessive sound stimulation  two types of SNHL Acoustic trauma…very brief exposure… Noise-induced hearing loss..excess of 85dB for 8 hours/day PTA Treatment Preventive: Therapeutic: Rest and avoidance of future trauma. Hearing aids

Non-Organic Hearing Loss Psychogenic (hysterical) Malingering. Diagnosis History Examination Audiometry; repeated audiograms give different results on each occasion.

Fracture base of the skul The longitudinal is more common than transverse. Deafness Tinnitus and Vertigo Tympanic membrane. Facial nerve palsy is seen more often in transverse fracture X-ray and CT scan of the base of skull

Treatment: Bleeding from the ear, with or without facial nerve palsy, after head injury means fracture base of skull until prove other wise. Never syringe the ear. No instrumentation of the ear. No caloric test. Systemic antibiotic… Facial nerve paralysis...

Tinnitus subjective sensation of noise Aetiology Central Peripheral (ear): External and middle ear. Cochlear: Retrocochlear It is usually more noticeable in bed at night when background noise is at its quietest. Investigation CBC, FBS and lipid profile. CT scan, MRI (acoustic neuroma). MRA and angiography (glomus jugulare). PTA.

Treatment Treatment of underlying cause and reassurance. Avoid smoking and caffeine. Drugs: I.V. lidocaine, antidepressants and anxiolytics like alprazolam. Ginkgo biloba improves brain function by increasing blood flow and oxygenation. 3. Tinnitus masking 4. Hearing aids