Tympanic Membrane - Infections and its Symptoms

Tympanic Membrane: The Source of Hearing

Dr.Surya Rao Poodipeddi profile Authored by Dr.Surya Rao Poodipeddi on 17 Mar 2014 - 17:22.

Before we go into the details about the tympanic membrane it is important to know the basics of the structure of the human ear.

The ear has three main parts namely the external, middle and internal ear. The external ear consists of the visible pinna and the ear canal. The pinna is a cartilaginous structure so designed as to funnel sound waves into the ear canal. The ear canal also called the external auditory meatus ends where the eardrum begins.

The eardrum separates the air filled ear canal and the middle ear, also filled with air and contains three tiny bones called auditory ossicles, named as malleus, incus and stapes. These bones transmit the sound waves from the eardrum to the membrane of the oval window which separates the middle ear from the inner ear. The fluid filled inner ear has a structure called cochlea that contains sensory receptors for hearing as well as a mechanism to control balancing.

The human Tympanic membrane, also called Eardrum is made of tissue similar to skin. It is the main organ in the ear. It receives sound vibrations from the external ear and transmits them to the auditory ossicles which are tiny bones in the tympanic cavity in the middle ear. It also serves as the lateral wall of the tympanic cavity and separates it from the external auditory canal. The tympanic membrane lies across the end of the external canal and resembles a flattened cone. It is attached to the three tiny bones in the middle ear

Of all the conditions affecting the eardrum perforation of the drum is the most common problem encountered. Perforation of the tympanic membrane is due to several causes which in turn are related to problems in the nose, throat and the ear itself. Of these, the commonest cause is due to trauma to the eardrum.

Trauma to the drum may be due to:

  • Penetration of the tympanum by objects placed in the ear canal like cotton buds.
     
  • Accidental entry to the ear canal like twigs on a tree or missiles like pencils and use of sharp edged objects.
     
  • Sudden over pressure as in an explosion or a sudden unexpected slap or a swimming and diving accident.

Apart from perforation to the eardrum, a penetrative injury to the tympanic membrane may lead to dislocation of the ossicular chain (the three tiny bones), fracture of the stapes, fragmentation of the ossicles and displacement of the fragments .a fistulous communication from the oval window and facial nerve injury as it exits from the brain through the ear.

Symptoms: The main symptom of a perforation is excruciating pain followed by bleeding from the ear. Ringing in the ears, called tinnitus and loss of hearing are the common symptoms that follow next. Loss of hearing becomes more apparent if the ossicular chain is involved or when the inner ear is injured. A feeling of giddiness called vertigo, when experienced, indicates that the inner ear is affected by the injury.

In all cases of perforation of the eardrum, it is essential to avoid entry of water to the middle ear and keep the ear as dry as possible to prevent severe infections like ottitis media.

Most of the bacterial infections if left unattended to or inadequately treated will lead to chronicity resulting in perforation and/or hearing loss. Treatment for infections depends on the bacteria responsible for the infection that can be identified through a Culture & Sensitivity test of the discharge from the ear which can be fluid or pus.

Use of eardrops should be avoided if one is sure about a perforation. In any case, consulting a pediatrician ( in the case of  a child) including an ENT specialist is a must, before starting the treatment.

 

*Disclaimer: This is not medical advice. The content is for educational purposes only. Please contact your doctor for any health care issues.