Tuesday, April 26, 2011

Causes of conductive hearing loss with intact normal mobile TM



Causes of conductive hearing loss with intact mobile TM
 (Tympanic membrane appears normal)

  1.    Ossicular chain discontinuity - Trauma....
  2.    Ossicular fixation – Otosclerosis..

Monday, April 25, 2011

Tuberculosis (T.B) Tympanic membrane


  • Double perforation
  • Chronic painless watery discharge
  • Hearing loss ( TM perforation + ossicles) 
  • Pale granulation that does not bleed  
  • Tubotympanic disease with facial nerve palsy
  • Pus will not grow anything, tissue granulation needed for AFB and HPE.
Double perforation – can occur post myringoplasty also.

Benign tumours of External Ear Canal تومورهای خوش خیم از کانال گوش خارجی




Exostosis
Osteoma
Definition
Most common bony abnormality of the EAC
True callus / hyperostosis of the bone at tympanic plate
Is a true neoplasm with fibrovascular channel

Multiple ,sessile, flat protuberance
Single , bony hard, pedunculated with stalk

Bilateral
Unilateral / slow growing
Position
Anterior and posterior canal walls. More near to TM.
At bony-cartilaginous junction , usually tympanosquamous suture
Etiology
Exact unknown
Cold-water – causes vasoconstriction of preiosteal blood vessel and reflex vasodilation leading to increase bone deposition
Swimmers ear / surfers
True neoplasm
No link to swimming
Histology
Onion like layers of compact lamella bone
No blood vessels
Cancellous bone
Fibrovascular channels
Clinical features
M:F 3:1
Small asymptomatic
Large – wax,CHL, bleeding while cleaning
Pain intermittently
Same
CT-scan
Densely solid bone
Increased heterogeneous
Treatment
If symptomatic
Post-auricular incision (due to multiple) excision
Use drill
A canalplasty can be performed to remove the offending lesions
Permeatal
Curette, drill

Can recur with re-exposure to cold water
Recurrence is unusual

Atelectic grades of the pars flaccid

Tos and poulison

Stage 1 = a slight dimple
Stage 2 = pars flaccida is retracted maximally and is draped over the neck of the malleus
Stage 3 = with erosion of the outer attic wall (scutum)
Stage 4 = full-blown attic retraction pocket (deep retraction with keratin accumulation which cannot be reached by suction)

Atelectic grades of pars tensa


Sade classification

Grade 1 = slight retraction of TM over the annulus
Grade 2 = the TM touches the long process of the incus
Grade 3 = the TM touches the promontory
Grade 4 = the TM is adherent to the promontory

BLUE DRUM

  1.   Glue ear
  2.   Cholesterol granuloma
  3.    Haemotympanum
  4.    Glomus tumour
  5.    High jugular bulb

Glomus Tympanicum

The Glasscock and Jackson’s system
Type 1 Glomus tumours are limited to the promontory,
Type 2 Denotes tumour completely filling the middle ear.
Type 3 Indicates tumour extending further into mastoid,
Type 4 Glomus tumours spread into external auditory canal and may have intracranial extension.

The Fisch classification of glomus tumors is based on extension of the tumor to surrounding anatomic structures and is closely related to mortality and morbidity.
  • Type A tumor - Tumor limited to the middle ear cleft (glomus tympanicum)
  • Type B tumor - Tumor limited to the tympanomastoid area with no infralabyrinthine compartment involvement
  • Type C tumor - Tumor involving the infralabyrinthine compartment of the temporal bone and extending into the petrous apex 
  • Type D tumor - Tumor with an intracranial extension