Eustachian Tube MCQs

This is a case of Acute Suppurative Otitis Media(ASOM) with bulging ear drum. It is an impending perforation, hence Myringotomy will be needed in poster inferior quadrant. Grommet is only used in glue ear or Eustachian tube dysfunction. Reference: Diseases of Ear, Nose and Throat & Head and Neck Surgery by P L Dhingra, 8 th Edition, Page - 75.

INDICATIONS Adenoid hypertrophy causing snoring, mouth breathing, sleep apnoea syndrome or speech abnormalities, i.e. (rhinolalia clausa). Recurrent Chronic otitis media with effusion associated with adenoid Recurrent ear discharge in benign CSOM associated with adenoiditis/adenoid hyperplasia. Dental Adenoidectomy does not correct dental abnormalities but will prevent its recurrence after orthodontic treatment. The grommet insertion. If myringotomy and aspiration combined with medical measures have not helped and fluid recurs, a grommet is inserted to provide continued aeration of middle ear. It is left in place for weeks or months or till it is spontaneously extruded Reference: Diseases of Ear, Nose, AND Throat by PL Dhingra, Pg no. 507

EUSTACHIAN TUBE : It connects the middle ear to the nasopharynx. Total Length 36 mm → Outer 12mm is bony& Inner 24mm is cartilagenous Angulation at birth it is nearly horizontal tube where as in adults it is 45° with horizontal. Main function of the Eustachian tube is middle ear ventilation. Tensor veli palatini muscle opens the tube during swallowing. Reference : Diseases of Ear, Nose and Throat & Head and Neck Surgery by P L Dhingra, 8th Edition, Chapter name: Eustachian Tube and its Disorders, Page number: 67

Toynbee's manoeuvre uses negative pressure to test eustachian tube function. It is a more physiological test. It is performed by asking the patient to swallow while nose has been pinched. This draws air from the middle ear into the nasopharynx and causes inward movement of tympanic membrane. The remaining three tests use positive pressure which causes outward movement of tympanic membrane. Reference: Diseases of Ear, Nose and Throat & Head and Neck Surgery by P L Dhingra, 8 th Edition, Page - 69, 70.

Reference: Diseases of Ear, Nose and Throat & Head and Neck Surgery by P L Dhingra, 8 th Edition, Page - 71.

History of mouth breathing, mal-occlusion of teeth in a 6 year old child are features of adenoid facies arising from adenoid hypertrophy. Adenoid hypertrophy causes bilateral eustachian tube blockage leading to formation of glue ear(serous otitis media). This causes conductive hearing loss. This child would need adenoidectomy(for adenoid hypertrophy) along with Myringotomy with Grommet insertion(to treat glue ear). Reference: Diseases of Ear, Nose and Throat & Head and Neck Surgery by P L Dhingra, 8 th Edition, pg. no. 288, 77

Nasopharyngeal cancer can cause conductive deafness (eustachian tube blockage), ipsilateral temporoparietal neuralgia (involvement of CN V) and palatal paralysis (CN X)- collectively called Trotter's triad .

CSF from anterior cranial fossa reaches the nose via Cribriform plate Roof of ethmoid air cells Frontal sinus. CSF from middle cranial fossa follows injuries to sphenoid sinus. In fractures of temporal bone , CSF reaches the middle ear and then escapes through the eustachian tube into the nose ( CSF otorhinorrhoea ) Overall most common site of CSF rhinorrhea is cribriform plate (Ethmoid bone). Most common cause now a days is iatrogenic (E.g. FESS) Second common cause is traumatic CSF leak – site of leak – Fovea Ethmoidalis (Frontal bone) Reference – Diseases of Ear, Nose and Throat, 8 th edition, page 192