After a cold and/or due to blockage of the Eustachian tube* fluid can be trapped in the middle ear. This is common in young children but can also occur in adults. Occasionally this can lead to a middle ear infection known as acute otitis media (AOM). AOM is very painful, causes earache, is usually associated with a high temperature and sometimes the ear drum will burst or perforate due to pressure build up. Acute otitis media usually settles without requiring antibiotics but if it persists for more than 48 hours or occurs frequently then a course of antibiotics may be necessary.
Persistent effusion is known as ‘glue ear’, it can fill the middle ear space reducing the ability of the middle ear to transmit sounds to the cochlea. This results in a conductive hearing loss. I therefore arrange a hearing test when this problem is suspected and also carry out a pressure test, which measures the movement of the eardrum. Usually the effusion resolves on it’s own as the mucous reabsorbs and the Eustachian tube clears. Obviously the hearing loss can be problematic and if it is persistent it can affect a child’s speech and language development. It can be very bothersome for adults too, affecting their ability to communicate at work and in social situations.
There are National Institute for Health and Care Excellence guidelines for treating this problem in children under 12. If the fluid (effusion) is persistent for longer than 3 months with an ongoing hearing loss at or beyond a certain level, then ventilation of the middle ears with Grommets may be necessary. Children with Cleft palate or Down’s syndrome are more susceptible to glue ear and there are specific guidelines for managing these children.
A grommet (or ventilation tube) is a tiny tube placed through the eardrum. One flange sits either side of the drum maintaining the middle ear pressure to prevent further build up of glue/mucous. Grommet insertion is usually done under a short general anaesthetic. A small hole is made in the eardrum, the fluid drained and the grommet inserted. As the drum heals it pushes the grommet out into the ear canal. Grommets usually stay in place for 9-12 months. In adults this can be longer as the drum tends to heal more slowly. Once they have fallen out and the drum has healed there is a chance that further middle ear effusions can occur. The grommet is therefore not a cure but in children they allow time for the Eustachian tube to develop and subsequently ventilate the middle ear naturally.
*The Eustachian tube is a small part of our anatomy that connects the middle ear to the back of the nasal cavity.
The ear canal has a bony portion (the inner 2/3rds) and a cartilaginous soft tissue portion (the outer 1/3rd). Wax is produced from glands located in the skin in the outer third of the ear canal. It provides a natural protective layer that helps to waterproof and has antibacterial properties. There is natural migration of skin from the centre of the eardrum down the sides of the ear canal to the waxy area and then out of the ear canal, hence the ears clean themselves. Using cotton buds can therefore push wax deeper into the ear canal and disturb/impair the natural self-cleaning process. If the canals are narrow or there is more wax production than ususal then blockage can occur. Eardrops, for example sodium bicarbonate may be able to breakdown the wax and help it to naturally fall out, sometimes however, removal by a specialist is necessary. This involves microsuction - looking into the ear canal with a microscope and using suction to carefully remove the wax.
Microsuction also forms an important part of the treatment if there is an outer ear canal infection - known as otitis externa (OE). The symptoms usually involve a combination of mucky discharge, pain, a feeling of blockage and occasionally hearing loss. This type of infection can occur after swimming or contamination from the outside with dirty water/debris. It is more likely to occur in people with an underlying skin condition. Some people have dry ear canal skin, which can be itchy. Sticking anything in the ear increases the risk of infection. The other part of the treatment for otitis externa is antibiotic eardrops targeted at the organisms causing the infection and sometimes, steroid eardrops to reduce inflammation. It is also important to keep the ear(s) dry when there is infection/discharge. The infection is less likely to clear if the ear keeps getting wet. Using cotton wool coated with Vaseline is a good way to prevent water getting in the ear when bathing or showering because Vaseline repels water.
When the Eustachian tube function is poor or the middle ear pressure struggles to equalise with atmospheric pressure* there is an increased likelihood of problems with middle ear infections. The middle ear cavity is lined with mucosa that produces mucous. If the mucosa is congested it thickens and produces more mucous - this is what happens during a cold or upper respiratory tract infection. If the inflammation persists then infection known as chronic otitis media can occur. There are a number of features of chronic middle ear infection but a hallmark of active disease is discharge, which we call otorrhoea. Surgery may be necessary for chronic infection. This involves a combination of clearing the inflamed tissue, potentially repairing or reinforcing the eardrum (tympanoplasty) and sometimes attempting to reconstruct the hearing mechanism (ossiculoplasty).
Disturbance of the natural skin clearing mechanism of the ear can lead to a build up of trapped skin. This can occur when there is chronic infection, or it can cause chronic infections. There may be an associated hole in the eardrum (see next section). The trapped skin is called cholesteatoma. Occasionally people are born with some trapped skin behind an intact eardrum - this is a congenital cholesteatoma. Cholesteatoma will slowly grow, expanding to fill available space; it will also erode surrounding bone. The erosion can damage important structures nearby including the little hearing bones (ossicles) causing hearing loss. In severe cases there can be erosion of the inner ear affecting the balance or hearing, there can also be erosion of bone causing pressure on the taste or facial nerves, which pass through the ear. The cholesteatoma can also spread upwards or inwards to the head cavity, which again is more serious. Cholesteatoma needs to be removed with surgery. There are a number of different operations (or surgical approaches) that can be carried out depending on the position and extent of the trapped skin. The aim of surgery is to remove all unhealthy tissue and attempt to improve the hearing by reconstructing the hearing mechanism. The relative complexity of this depends on the extent of the problem. More than one operation may be necessary because there is a chance of recurrent or residual disease.
We can now look for cholesteatoma by doing a specific type of MRI (magnetic resonance imaging) scan that has diffusion weighted sequences. This is particularly useful about a year after an initial operation to look for further trapped skin. Our radiologists can confidently detect cholesteatoma that is 3mm or greater in size.
*Atmospheric pressure is the pressure of the air that surrounds us on earth.
When the Eustachian tube function is poor or the middle ear pressure struggles to equalise, there is a chance that the normally tight eardrum, can slowly get sucked inwards by negative pressure behind the drum. This can lead to a retraction which may affect the ability of the ear to clean itself and clear skin debris. There is also a risk of erosion of the little hearing bones (ossicles) causing hearing loss. Inserting a grommet can temporarily equalise the pressure and stop the drum from retracting further but this will only work while the grommet is in place and sometimes the retraction can progress regardless. I will usually monitor a retraction and keep track of whether it is progressing. If the hearing deteriorates that may be the time to offer surgical intervention to reinforce the eardrum (tympanoplasty) and attempt to reconstruct the hearing mechanism (ossiculoplasty). I can do this in a number of ways. Factors that influence the surgical options are the amount of hearing loss, the sate of the remaining hearing bones and the shape of the ear canal. Depending on the symptoms and how the ear looks having been examined with the microsope, a CT (computerised tomography) scan may be necessary to give me more information about the bony anatomy of the ear. This will then enable a discussion about the best way to improve the situation.
A hole in the eardrum may occur due to marked pressure change, trauma or infection. If the hole is not causing any problems it can be monitored. If there are recurrent infections with mucky discharge (otorrhoea) then I can offer an operation to close the hole (myringoplasty or tympanoplasty). This can be done in a number of ways and the best method is determined by a number of factors; including the position and size of the hole, any underlying hearing bone involvement and the shape of the ear canal. Similar to ear drum retractions a CT scan may be helpful to gain more information about the bony anatomy and check there is not more going on than meets the eye. It then enables a discussion about the best way to improve the situation and help to plan any surgery.
Hearing loss can occur for a multitude of reasons. Some people are born with significant hearing loss, others inherit a type of hearing loss that steadily progresses. Commonly people get hearing loss as they get older due to ‘wear and tear’ in the inner ear. People can develop hearing loss due to infections, trauma, noise exposure, medications or a condition called otosclerosis.
The hearing test (a pure tone audiogram) is an important part of the assessment and depending on the hearing level or suspected cause I may ask for a number of different tests. Investigation may also require a CT scan, and/or an MRI scan.
Otosclerosis is a condition affecting the bone of the inner ear. Altered bone turnover/ formation leads to fixation of the stapes (the innermost of the 3 hearing bones). This causes a conductive hearing loss. Generally the more abnormal bone there is, the worse the hearing will be. When otosclerosis is far advanced it also affects the inner ear and patients develop a sensorineural hearing loss as well as the conductive loss.
Hearing aids are usually a suitable option for improving hearing loss. Depending on the type and extent of hearing loss surgery may be possible. This would involve either reconstructing the natural hearing mechanism or when that is not possible a small piece of titanium can be used to bridge the gap between the eardrum and the cochlea (inner ear). Surgery for otosclerosis involves lifting up the ear drum to access the stapes bone. The immobile stapes is removed (Stapedectomy) and replaced with a tiny prosthesis. Stapes surgery can usually be done down the ear canal without a cut on the outside. A laser is used, minimising trauma to the hearing mechanism and inner ear.
To be completed
For patients unable to wear conventional hearing aids and when traditional surgical techniques are not capable of improving the hearing, an auditory implant may be an option. There are currently 3 main types; bone conducting implants, middle ear implants and cochlear implants.
Bone conducting implants use the principle that sound causes vibration and that tiny vibrations can be transmitted directly through the bone of the skull to the cochlea, bypassing the ear canal and middle ear when they are not working properly.
Middle ear implants actively vibrate a middle ear structure, powering the natural hearing mechanism, amplifying sound which is transmitted directly into the inner ear for ear specific stimulation.
Cochlear implants are for patients with severe or profound hearing loss that get very little benefit from well fitted conventional hearing aids. A cochlear implant electrically stimulates the ‘hearing nerves’ (spiral ganglion cells) in the cochlea. The sound they provide is different to natural acoustic hearing, however, patients learn to adapt to the difference and can manage very well in day-to-day life. Children born with severe to profound hearing loss who have cochlear implants can develop normal speech and language at the same rate as their normal hearing peers.
Assessment for consideration of hearing implants involves appointments with different specialists including Audiologists and Speech and Language Therapists. Any decision needs to be considered in light of the anatomical findings with a multi-disciplinary team approach from a number of experts. The most appropriate type of implant can then be offered to suit each patient’s hearing needs.
I work with a team of experts to assess and manage patients that may be hearing implant candidates. I carry out all types of hearing implant surgery and it is part of my routine NHS practice.
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