Lec 7 Flashcards
Classification of inner ear diseases?
• Congenital :
Michel s malformation : cochlear aplasia
Mondini s malleolar: cochlear hypoplasia ( 1,5 turns )
• neoplastic:
Ascoustic neuroma
• traumatic
Noise trauma , noise induced HL
Perilymph fistula : usually caused by either surgical or traumatic as
• otitic barotrauma
• fractural base of skull ( otorrhea , otorhinorrhea)
• post surgical : stapedectomy
• inflammatory
Labyrinthitis
Vestibular neuritis
• miscellaneous
Ototixicity
Senile deafness ( presbyacusis)
Bppv
Meniere disease
Cochlear otosclerosis ( rare)
Talk about noise trauma , noise induced HL
(3)
1- type of noise
- sudden exposure to loud sound : ( acoustic trauma ) ex : explosion , gunfire
- prolonged exposure to loud sound : machines , traffics , music
• sound that causes injury to inner ear exceeds 90 dB ( 90-140)
2- type of HL
- temporary: few hours to few days
- prolonged : never back to normal
3- treatment
Preventable more than curable
- prevent exposure to loud sound
- personal hearing protection : earplugs , earmuffs during exposure
- hearing aid in severe cases
Talk about labyrinthitis
(3)
Types
1- viral : measles , rubella cytomegalovirus
2- bacterial :
*Infection from ME ( otogenic) as a comp of csom
*Infection from internal auditory canal : as acomp of meningitis
*syphilitc labyrinthitis :
•secondary endolymphatic hydrops
• same cp of meniere disease
• with sypilitic stigmata ( hutchinson teeth, interstial keratitis
- toxic labyrinthitis ( otoxicity)
Talk about vestibular neuritis
(4)
1- def : acute failure of vesitbular function due to viral infection most probably causing micro haemorrhage pressing on
2- duration : few days to few weeks
3- cp (4) :
• acute attacks of severe vertigo
• nausea
• vomiting
• no hearing problems
4- treatment (4) :
• antivertigo drugs : symptomatic in first few days
• no anti viral drugs
• vestibular excersise
• steroid : antiedemic and inflammatory ( tapering method )
Talk about ototoxcity
(4)
1- def : damage of hair cells of inner ear ( especially outer ) by medications
2- medications
• amino glycoside: kana , genta , streptomycin : permanent cochlear , vestibular damage
• chemotherapeutics ( cytotoxic ) : cisplatin : permanant cochlear , vestibular damage
• salyclits ( aspirin) : reversible cochlear damage
• diuretics ( fruesmide) :reversible cochlear damage
• quinine ( antimalarial ) : reversible cochlear damage
3- cp : bilateral SNHL ( high tone ) and tinnitus and vertigo investiblotoxic drugs
4- treatment:
-Monitoring of auditory fuction in patients taking otoxic drugs
-Hearing aid
Talk about presbyacusis
(5)
1- the commenest cause for snhl ingeneral / elderly
2- age related ( in old )
3- causes : degeneration of hair cells , cochlear n , stria vascularis and stiffness of basilar membrane
4- cp : bilateral symmetricalprogressive snhl with tinnitus in elderly without evident cause
5- treatment : hearing aid
Talk about bppv
(5)
Benign paroxysmal positional vertigo
1- common cause for vertigo
2- def : paroxysmal attacks of vertigo of sudden onset short duration related to certain positions
3- aetiology : depris of sequestrated otocinia from utricle ( macula ) to pcc due to head trauma
4-cp : acute attacks of vertigo
with nystagmus (10-20s)
without hearing problems
+ dix hallpike test
( • while the patient is sitting on examing bed , he turns his head towards the examiner 30 then he lies down till his head is below the bed level , the positive test shows nystagmus , veritgo when the diseased ear is down )
5-treatment :
Repositioning of depris to utricle ( macula) by epley manuveur
Pscc obliteration or singular nerve neuroctomy ( pscc nerve) if epley failed
Talk about meniere disease
(7)
1- endolymphatic hydrops
2-def : distension of membranous labyrinth by endolymph characterised by recurrent attacks of deafness, tinnitus, vertigo +- ear fullness
3- aetiology : excessive formation ( stria vascularis ) or lack in its drainage ( endolymphatic sac) , the main exact cause is unkown but may be because ( VASAS)
• viral infection
• autoimmune
• salt and wter retention
• allergy
• sympathetic overtone
4- incidence
Unilateral ( bilateral in 25)
Females = males
More in Around 50 years
5-cp
Recurrent attack of this triad
• vertigo (3)
- last for minutes to hours never days
- between the attack patient is normal
- associated with nystagmus, nausea, vomiting
• deafness (3)
- snhl ( low tone ) ( as the apex is the most compressed)
- flactuant
- associated with hypersensitivity of loud sound ( + recruitment)
• tinnitus
(most patients have ear fullness )
6-investigations
Audiological (3)
- PTA : (SNHL low tone fluctuant)
- +ve glycerol test : hearing is better on PTA after intake of glycerol ( diuretic)
- electrocochleography : may be helpful ( diminshed potienls)
Vestibular
- caloric test shows reduced caloric response in diseased ear
7- treatment
Medical
During the attack (3)
- complete bed time
- antivertigo : dramamine
- antiemtic : chlorpromazine
Between the attack
- salt restriction
- diuretics : frusamide ( lasix )
- vasodilator: betahistidine
- if severe bilateral snhl , toxic dose of streptomycin ( medical labyrinthectomy)
Surgical
-If hearing is bad : surgical labyrinthectomy ( bilateral )
intra tympanic injection of amino glycosides( unilateral )
-If hearing is good : endolymphatic sac decompression ( removal of bone around it ) if failed then vestibular n neuroctomy
Talk about acoustic neuroma
(9)
1- vestibular schwannoma
2- benign
3- from schwann cells of vestibular n
4- arise in CPA passing internal auditory canal at the gilal neurolemmal junction of vestibular n
( cpa space has 7,8 passing through it , trigiminal passes above , lower four cranial pass below )
5- cp (4)
• otological :
Deafness : SNHL ( unilateral )
Tinnitus ( unilateral)
Vertigo ( rare as the tumour is gradual )
• neurological
5th : loss of corneal reflex
7th : rare and late ( its motor fibres are hard unlike in glomus , squmaus )
9th : chocking
10th : horsaeness of voice
11th : dropness of shoulders
12th : paralysis of tongue
• cerebellar
Ataxia , nystagmus , staccato speech
• terminal
+ ICP
6- investigations (5)
- CT with contrast : widned internal auditary canal
- MRI : the bst diagnostic investigation, can see even small tumors
- PTA : unilateral SNHL
- speech audiometry : poor speech discrimination ( محمد واحمد )
- ABR (auditory brain stem response ): delayed wave 5
7- dd of cpa lesions (4)
- acoustic neuroma ( the commonest)
- meningioma
- arachniod cyst
- congenital cholesteatoma
8- unilateral in general except with multiple neurofibromatosis
9- treatment
Surgical exision ( > 3cm)
Stereotactic radio surgery ( gamma knife ) if it is small
Unilateral ?
Bilateral ?
In ear disease
Uni
- meniere disease
- acoustic neuroma
Bi
- otosclerosis
- presbyacusis
- ototoxcity
Ear fullness ??
- otitic barotrauma
- meniere disease
Vertigo without deafness and tinnitus
- vestibular neuritis
- bppv
