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..

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

تشخیص افتراقی 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