Hearing Diseases

Otitis Media Otitis media is a group of inflammatory diseases of the middle

ear. The two main types are acute otitis media (AOM) and otitis media with effusion (OME).AOM is an infection of abrupt onset that usually presents with ear pain. In young children this may result in pulling at the ear, increased crying, and poor sleep. Decreased eating and a fever may also be present. OME is typically not associated with symptoms. Occasionally a feeling of fullness is described. It is defined as the presence of non-infectious fluid in the middle ear for more than three months. Chronic suppurative otitis media (CSOM) is middle ear inflammation of greater than two weeks that results in episodes of discharge from the ear. It may be a complication of acute otitis media. Pain is rarely present. All three may be associated with hearing loss.

Causes

The common cause of all forms of otitis media is dysfunction of the Eustachian tube. This is usually due to inflammation of the mucous membranes in the nasopharynx, which can be caused by a viral URI, strep throat, or possibly by allergies. Because of the dysfunction of the Eustachian tube, the gas volume in the middle ear is trapped and parts of it are slowly absorbed by the surrounding tissues, leading to negative pressure in the middle ear. Eventually the negative middle-ear pressure can reach a point where fluid from the surrounding tissues is sucked in to the middle ear's Eustachian tube, the gas volume in the middle ear is trapped and parts of it are slowly absorbed by the surrounding tissues, leading to negative pressure in the middle ear. Eventually the negative middle-ear pressure can reach a point where fluid from the surrounding tissues is sucked in to the middle ear's

Prevention Long-term antibiotics, while they decrease rates of infection during

treatment, have an unknown effect on long-term outcomes such as hearing loss. This method of prevention has been associated with emergence of antibiotic-resistant otitic bacteria. They are thus not recommended.

Pneumococcal conjugate vaccines when given during infancy decrease rates of acute otitis media by 6%–7% and, if implemented broadly, would have a significant public health benefit. Influenza vaccine is recommended annually.

Risk factors such as season, allergy predisposition and presence of older siblings are known to be determinants of recurrent otitis media and persistent middle-ear effusions (MEE).

History of recurrence, environmental exposure to tobacco smoke, use of daycare, and lack of breastfeeding have all been associated with increased risk of development, recurrence, and persistent MEE. Thus, cessation of smoking in the home should be encouraged, daycare attendance should be avoided or daycare facilities with the fewest attendees should be recommended, and breastfeeding should be promoted.

There is some evidence that breastfeeding for the first year of life is associated with a reduction in the number and duration of OM infections. Pacifier use, on the other hand, has been associated with more frequent episodes of AOM.

Evidence does not support zinc supplementation as an effort to reduce otitis rates except maybe in those with severe malnutrition such as marasmus.

Otosclerosis

This is an inherited disease. The primary form of hearing loss in otosclerosis is conductive hearing loss (CHL) whereby sounds reach the ear drum but are incompletely transferred via the ossicular chain in the middle ear, and thus partly fail to reach the inner ear (cochlea). This usually will begin in one ear but will eventually affect both ears with a variable course. On audiometry, the hearing loss is characteristically low-frequency, with higher frequencies being affected later.

Sensorineural hearing loss (SNHL) has also been noted in patients with otosclerosis; this is usually a high-frequency loss, and usually manifests late in the disease. The causal link between otosclerosis and SNHL remains controversial. Over the past century, leading otologists and neurotologic researchers have argued whether the finding of SNHL late in the course of otosclerosis is due to otosclerosis or simply to typical presbycusis.

Causes and Genetics

It may be that a genetic tendency to develop otosclerosis is inherited by some people. Then a trigger, such as a viral infection (like measles), actually causes the condition to develop.

The disease can be considered to be hereditary, but its penetrance and the degree of expression It may be that a genetic tendency to develop otosclerosis is inherited by some people. Then a trigger, such as a viral infection (like measles), actually causes the condition to develop.

The disease can be considered to be hereditary, but its penetrance and the degree of expression

Medical treatment

Earlier workers suggested the use of calcium fluoride; now sodium fluoride is the preferred compound. Fluoride ions inhibit the rapid progression of disease. In the otosclerotic ear, there occurs formation of hydroxylapatite crystals which lead to stapes (or other) fixation. The administration of fluoride replaces the hydroxyl radical with fluoride leading to the formation of fluorapatite crystals. Hence, the progression of disease is considerably slowed down and active disease process is arrested. This treatment cannot reverse conductive hearing loss, but may slow the progression of both the conductive and sensorineural components of the disease process. Otofluor, containing sodium fluoride, is one treatment. Some success has been claimed with a second such treatment, bisphosphonate medications that inhibit bone destruction. Neither approach has been proven to be beneficial after the commonly preferred method of surgery has been undertaken.

Surgical treatment and Amplification

There are various methods to treat otosclerosis. However the method of choice is a procedure known as Stapedectomy. Early attempts at hearing restoration via the simple freeing the stapes from its sclerotic attachments to the oval window were met with temporary improvement in hearing, but the conductive hearing loss would almost always recur. A stapedectomy consists of removing a portion of the sclerotic stapes footplate and replacing it with an implant that is secured to the incus. This procedure restores continuity of ossicular movement and allows transmission of sound waves from the eardrum to the inner ear. A modern variant of this surgery called a stapedotomy, is performed by drilling a small hole in the stapes footplate with a micro-drill or a laser, and the insertion of a piston-like prothesis. The success rate of either surgery depends greatly on the skill and the familiarity with the procedure of the surgeon. However, comparisons have shown stapedotomy to yield results at least as good as stapedectomy, with fewer complications, and thus stapedotomy is preferred under normal circumstances.

Although hearing aids cannot prevent, cure or inhibit the progression of otosclerosis, they can help treat the largest symptom, hearing loss. Hearing aids can by tuned to specific frequency losses. However, due to the progressive nature of this condition, use of a hearing aid is palliative at best. Without eventual surgery, deafness is likely to result

Tinnitus

Tinnitus is the hearing of sound when no external sound is present. While often described as a ringing, it may also sound like a clicking, hiss or roaring. Rarely, unclear voices or music are heard. The sound may be soft or loud, low pitched or high pitched and appear to be coming from one ear or both. Most of the time, it comes on gradually .In some people, the sound causes depression, anxiety or interferes with concentration

Causes There are two types of tinnitus: subjective tinnitus and objective tinnitus.

Tinnitus is usually subjective, meaning that others cannot hear it. Occasionally, tinnitus may be heard by someone else using a stethoscope: in which case, it is objective tinnitus.

Subjective tinnitus is the most frequent type of tinnitus. It can have many possible causes but, most commonly, results from hearing loss. A frequent cause of subjective tinnitus is noise exposure which damages hair cells in the inner ear causing tinnitus. Subjective tinnitus can only be heard by the affected person and is caused by otology, neurology, infection or drugs.

There is a growing body of evidence suggesting that tinnitus is a consequence of neuroplastic alterations in the central auditory pathway. Despite the opinion amongst researchers that tinnitus is primarily a central nervous system pathology, there certainly exists a class of people whose tinnitus is peripherally based.

The most common cause of tinnitus is noise-induced hearing loss. Hearing loss may be implicated even for people with normal audiograms. Hearing loss may have many different causes; but among tinnitus subjects, the major cause is cochlear damage.

Ototoxic drugs (such as aspirin) can also cause subjective tinnitus, as they may cause hearing loss, or increase the damage done by exposure to loud noise

Prevention

Prolonged exposure to loud sound or noise levels can lead to tinnitus. Ear plugs or other measures can help with prevention.

Several medicines have ototoxic effects, and can have a cumulative effect that can increase the damage done by noise. If ototoxic medications must be administered, close attention by the physician to prescription details, such as dose and dosage interval

can reduce the damage done. Tinnitus can also occur due to the discontinuation of therapeutic

doses of benzodiazepines. It can sometimes be a protracted symptom of benzodiazepine withdrawal and may persist for many months.

Usher syndrome

Usher syndrome is an inherited condition characterized by hearing impairment and progressive vision loss. The vision loss is due to retinitis pigmentosa (RP), a degenerative condition of the retina, and usually appears during adolescence or early adulthood. Balance may also be affected. Symptoms vary from person to person and progress at different rates.

Hearing loss in Usher syndrome is due to a genetic mutation (alteration) affecting nerve cells in the cochlea, a sound-transmitting structure of the inner ear. The same genetic defect also adversely affects photoreceptor cells in the retina, leading to vision loss.

Types of Usher Syndrome

There are at least three different forms of Usher syndrome. People with Usher syndrome type 1 (USH1) are usually born with severe hearing loss and experience problems with balance. The first signs of RP night blindness and loss of peripheral vision — usually appear in early adolescence.

In Usher syndrome type 2 (USH2), newborns have moderate to severe hearing impairment. Symptoms of RP typically start shortly after adolescence. Visual problems progress less rapidly than in Usher type 1 and hearing loss usually remains stable.

A rarer third type of Usher syndrome (USH3) was documented in 1995. Children with USH3 are usually born with good or only mild impairment of hearing. Their hearing and vision loss is progressive, starting around puberty. Balance may also be affected

Treatment While there are no treatments for Usher syndrome, intensive research is

underway to discover the causes of, and treatments for, all types of the disease. Researchers have also identified a nutritional therapy to slow the rate of vision

loss in some RP patients. Although not a cure, they found that vitamin A palmitate can slow retinal degeneration in some people with RP and Usher syndrome type 2. They also showed that docosahexaenoic acid (DHA) — an omega-3 fatty acid — can enhance While there are no treatments for Usher syndrome, intensive research is underway to discover the causes of, and treatments for, all types of the disease.

Researchers have also identified a nutritional therapy to slow the rate of vision loss in some RP patients. Although not a cure, they found that vitamin A palmitate can slow retinal degeneration in some people with RP and Usher syndrome type 2. They also showed that docosahexaenoic acid (DHA) — an omega-3 fatty acid — can enhance

Meniere’s disease is a disorder of the inner ear that can affect hearing and balance. It is characterized

by episodes of vertigo, tinnitus, and hearing loss. The hearing loss comes and goes for some time, alternating between ears, then becomes permanent.

The condition is named after the French physician Prosper Ménière, who, in an 1861 article, first reported that vertigo was caused by inner ear disorders. The condition affects people differently; it can range in intensity from being a mild annoyance to a lifelong condition

Sometimes it is also called endolymphatic hydrops, but Ménière's is idiopathic by definition and endolymphatic hydrops can exist for other non-idiopathic reasons than Ménière's. Also individuals with endolymphatic hydrops do not always progress to Ménière's disease.

Ménière's disease affects about 190 people per 100,000. Recent gender predominance studies show that Ménière's tends to affect women more often than men. The typical age of onset for the disease is during the adult years, with prevalence increasing with age.

Causes

Ménière's disease is linked to endolymphatic hydrops, an excess of fluid in the inner ear.The membranous labyrinth, a system of membranes in the ear, contains a fluid called endolymph. In Ménière's disease, endolymph bursts from its normal channels in the ear and flows into other areas, causing damage. This accumulation of fluid is referred to as "hydrops". The membranes become dilated (stretched thin, like a balloon) when pressure increases and drainage is blocked. This may be related to swelling of the endolymphatic sac or other tissues in the vestibular system of the inner ear, which is responsible for the body's sense of balance.

In some cases, the endolymphatic duct may be obstructed by scar tissue, or may be narrow from birth. In some cases there may be too much fluid secreted by the stria vascularis. The symptoms may occur in the presence of a middle ear infection, head trauma, or an upper respiratory tract infection, or from using aspirin, smoking cigarettes, or drinking alcohol. They may be further exacerbated by excessive consumption of salt in some patients. It has also been proposed that in some patients Ménière's disease could be caused by the reactivation of a latent herpes virus. Vrabec (2003) demonstrates a "universal prevalence of HSV [Herpes simplex virus] in vestibular ganglia of patients with MD (menieres disease), suggesting an association between the virus and the clinical syndrome".

Management Several environmental and dietary changes are thought to reduce the frequency

or severity of symptom outbreaks. It is believed that since high sodium intake causes water retention, a diet high in salt can lead to an increase (or at least prevent the decrease) of fluid within the inner ear, although the relationship between salt and the inner ear is not fully understood. Thus, a low sodium diet is often prescribed, with sodium intake reduced to one to two grams of sodium per day (equivalent to approximately 2.5 to 5 grams of table salt, or a little more than one third to two thirds of a teaspoon). By comparison, the recommended Upper Limit (UL) for sodium intake is 2.3 grams per day, and most people are recommended to consume less than 1.5 grams, but on average people in the United States consume 3.4 grams per day.

Diuretics have traditionally been prescribed to increase sodium excretion through the urine and thus (it is thought) enhance the effect of sodium restriction, although there is no definite supportive evidence. Some sources recommend taking two grams of potassium or more daily for similar reasons.

Getting adequate sleep and avoiding stress is an important aspect of managing the symptoms of Ménière's disease.

Additionally, patients may be advised to avoid alcohol, caffeine, and tobacco, all of which can aggravate Ménière's symptoms.[citation needed] Many patients have allergy testing to see if they are candidates for allergy desensitization, as allergies have been shown to aggravate Menière‘s symptoms.