Anatomically, an ear is a vertebrate organ of hearing and is responsible for sensing and collecting sounds as well as maintaining equilibrium. The ear is divided into three sections, the outer ear (pinna), the middle ear, and the inner ear. Each section of the ear has its unique functions. The external ear consist of two portions, the first being the pinna, the skin covered flabby cartilage of the ear visible on both sides of the head. The basic function of the outer ear or pinna is to protect the eardrum (tympanic membrane).
The outer ear also functions to collect sound waves to the eardrum through the ear canal. The second component of the external ear is the auditory ear canal or meatus. There are modified sweat glands that secrete ear wax in the ear canal. If ear wax is excessive, the ear drum can be damaged or lead to blockage of the transmission of sound. Unlike those of animals, human ears are usually of same size. They only grow from infancy up until youth. The middle ear refers to the hollowed air-filled bony space in the temporal bone of the skull behind the eardrum.
It is just separated from the outer ear by the ear drum. There are three tiny bones (auditory ossicles) in the tympanic cavity that vibrates when exposed to sound waves, known as the malleus (hammer), incus (anvil), and stapes (stirrup). These bones form a chain around the middle ear and extend to the oval window of the inner ear and their main function is to amplify sound. The middle ear is connected to the back of the throat and nose through the eustachian tube. The eustachian tube is the auditory openings that we open when we yawn or swallow.
The inner ear is the most complicated component of the auditory system located into a tiny space of the hardest temporal bone and inaccessible to direct examination or clinical manipulation. The inner ear comprise of three intimately related structures. The cochlea (spiral tube), three semicircular canals and the vestibule (labyrinth). The cochlea is directly responsible for hearing and contains nerves responsible for converting energy vibrations within the inner ear fluid into nerve impulses which can be transmitted to the brain. While the vestibule (labyrinth) and semicircular canals function to maintain balance or equilibrium.
The main functions of the ear are sound detection, hearing allowance, and balance maintenance is the main functions of the ear. The most basic function of the ear is hearing. The following is the short description of the hearing process: * The first step is when the pinna collects external sounds that enter through the meatus or ear canal as sound waves. The ear drum begins to vibrate as these sound waves strikes. These vibrations pass through to the three ossicles of the middle ear (hammer, anvil and stapes) where they are amplified.
As the transmission proceeds, the vibrations first hit the hammer, then the hammer pushes the anvil, and the anvil hits the stapes. The vibrations are finally interpreted as sound in the brain after being transmitted and transformed into nerve signals by the cochlea (snail shaped component of the inner ear). This is due to the connectivity of the oval window of the inner ear to the edge of the stapes. When the stapes vibrates, they always transmit the sound vibrations to the inner ear. The other important function of the ear is to help maintain balance.
Oriented at the right angles to each other are three semicircular canals of the inner ear. Whenever the head is turned or change position, the resulting movement of fluids within these canals help the brain to identify or detect the extent of movement and positioning of the head. In response to gravity, another part of the inner ear sends information to the brain when the head is held still in a stagnant position. Meniere’s Disease. Meniere’s disease is a disorder of the flow of fluids of the inner ear characterized by recurrent vertigo, hearing loss, and tinnitus.
The cause of Meniere’s is unknown but as of 2002 scientist are studying several possible causes, including noise pollution, viral infection, or alterations in the pattern in blood flow in the structures of the inner ear. Since Meniere’s sometimes runs in families, researchers are also looking into genetic factors as possible causes of the disorder (Gayle Encyclopedia). But they do this there’s a link between migraine headache, German scientists reported in 2002 that lifetime prevalence of migraine was 56% in patients diagnosed with Meniere’s disease as compared to 25% controls.
Researchers noted that further work is necessary to determine the exact nature of the relationship between the two disorders. Symptoms of Meniere’s disease are caused by pain in the inner ear region that may even extend to the area of the neck. Other symptoms include: Vertigo, Nausea, Vomiting and sweating, Fullness in the ear, Tinnitus, Hearing loss, Imbalance. Other symptoms of Meniere’s disease that are often associated with aging include: extreme tiredness, stiffness in the neck, headaches, memory loss and loss of equilibrium.
This disease usually starts between the ages of 20 to 50 years but it is not uncommon for the Elderly to develop it with no prior medical history. Meniere’s disease is diagnosed and treated by a otolaryngologist (ENT doctor). Some doctors will perform a hearing test to establish the extent of hearing loss cause by this disease. To rule out other diseases a doctor also might conduct a MRI or a CT scans of the brain. Meniere’s disease does not have a cure but a doctor might recommend some of these treatments to help you cope. * Medications.
Prescription drugs such as meclizine, diazepam, glycopyrrolate, and lorazepam can help relieve the dizziness and shorten attacks. * Salt restrictions. Limiting dietary salt and taking diuretics help with some people control dizziness by reducing the fluid the body retains which may lower fluids volume and pressure in the inner ear. * Dietary and Behavioral . Some people claim that caffeine, chocolate, and alcohol make their symptoms worse and either avoid or limit it in their diet. * Cognitive Therapy. This is a type of a talk therapy that helps people focus on how they interpret and react to life experiences.
Some people feel this helps them cope with the unexpectedness of attacks and reduces their anxiety about future attacks . (NIDCD) It is important for a person who has meniere’s to gain control over the illness to be able to prevent future attacks. This often happens by medical therapy and rehabilitated lifestyle. In some cases where medical treatment and lifestyle modification are not successful (usually less than one-third), surgical treatment is often the solution. There also have been ground breaking surgeries, the old way to get rid of meniere’s disease is basically to get rid of your hearing.
Now there are so many options that are now individualized for each person’s ear. Dr. Mark Levenson, will walk you through all the wonderful surgeries that are so different there…well let’s just say its really cool. Surgery ENDOLYMPHATIC SAC DECOMPRESSION – I “The actual cause of the fluid accumulation in the inner ear, the condition which sets off the whole process to begin with in Meniere’s Disease, is not known. In animals, experiments have been done which show that if the sac that drains fluids from the inner ear is tied off, fluid will build up in the inner ear and cause changes comparable to those in humans.
Because of the observation of fluid build up in the inner ear of animals, the most commonly performed operation in the past involved drainage of the endolymphatic sac in patients with Meniere’s. ” “ The endolymphatic sac decompression operation is performed by making an incision behind the involved ear and exposing the mastoid bone. The mastoid is opened, and the facial nerve is identified in its course through the mastoid. The bone over the endolymphatic sac is then exposed and once identified, the sac is opened. A non-reactive sheet of silastic or a valve is inserted into the sac to allow for future drainage, when fluid reforms.
The operation takes about an hour. ” ”In theory, the endolymphatic sac operation should decompress the excessive fluid within the inner ear chambers and allow the inner ear to re-equilibrate, taking pressure off the nerve endings of hearing and balance. Studies have shown little positive effect on hearing from drainage of the endolymphatic sac. ESD often does NOT cure Meniere’s sufferers. Vertigo subsides after surgery in about 70 percent of Meniere’s cases, but vertigo symptoms recurr with the same severity as before in a significant number of individuals within three years of surgery.
” THE LABYRINTHECTOMY – II VESTIBULAR NEURECTOMY – III “Historically, ear surgeons have tried many procedures to cure vertigo. In individuals with complete or near complete hearing loss in one ear due to Meniere’s, a surgical procedure termed a labyrinthectomy is usually curative. Using the same approach through the mastoid bone as the older procedure, the endolymphatic sac operation, the inner ear balance organ (the labyrinth) is exposed. The semicircular canals are then carefully drilled away, exposing the nerve of balance which is completely removed.
” “Following surgery, there is often severe vertigo for a day or two. This can be controlled with medication. After a week, the patient experiences a period of moderate imbalance without vertigo while the opposite ear takes over the command of the entire balance function and assumes full control. This period can last six to eight weeks. The more active an individual is after surgery, the more rapid the recovery of balance function will be. ” “The two inner ear balance centers can be thought of as gyroscopes. The gyroscope of each ear helps to control balance by sending signals of the position we are in to the brain.
If one gyroscope is faulty, as is the case in Meniere’s, the brain has trouble adapting, since it is intermittently getting wrong signals mixed with correct ones. However, if the inner ear balance nerve is completely shut off on one side and the “faulty gyroscope” removed, the brain will adapt to this new situation, since it now receives only correct signals from the one remaining gyroscope (inner ear) which will control the entire balance function. This is the reason labyrinthectomy is successful. ” “Labyrinthectomy does not spare any residual hearing.
In a young individual, surgery that conserves the remaining hearing in the ear affected by Meniere’s is most important. A certain percentage of young people with Meniere’s may also develop the illness in their opposite ear later in their lifetime: 10 to 20 percent. ” “If there is substantial hearing present, vestibular neurectomy may be a prefered surgical option which can cure vertigo and preserve hearing. ” “Vestibular neurectomy involves the discrete sectioning of the nerve of balance near where it comes out of the brain. The hearing portion of the nerve is thus preserved.
Ninety to 95 percent of vestibular neurectomies will result in cure of vertigo. ” “Hearing is preserved at the level experienced before surgery in most cases. The operation is a team effort performed by an ear surgeon and a neurosurgeon. Since the nerve must be identified as it exits the brain, the vestibular neurectomy is an intracranial operation. ” “Recovery from a vestibular neurectomy is similar to that of a labyrinthectomy. However, because it is an intracranial (brain) operation, closer post-operative monitoring will be the order of the day.
Younger people (those who are less than 60) who are in good health are offered this operation as the most definitive operation both to cure vertigo from Meniere’s and preserve hearing. This minimally invasive operation takes less than two hours. A hospital stay of three or four days is usually necessary. ” “Other surgical procedures have been attempted over the years to treat Meniere’s Disease. Although the endolymphatic sac operation seems appealing from a physiologic point of view, the operation fails in many cases.
This failure is probably due to the fact that the canal leading to the endolymphatic sac from the inner ear may be obstructed or clogged. Draining the sac can remove the excess fluid within it, but does not allow continuous drainage of fluid from the inner ear to the sac. ” CHEMICAL LABYRINTHECTOMY: – IV “ In the past several years, studies have been conducted placing specific antibiotics into the inners ear to treat Meniere’s Disease. It has been known for over forty years that streptomycin, an antibiotic rarely used today, is toxic to the nerve of balance.
This information has been used by researchers who give very small doses of streptomycin (or more recently, gentamicin) directly into the ear. The intent of this treatment is to deliver sufficient medication to stabilize or partially destroy the nerve endings of balance while sparing the nerves of hearing. Further research is underway. There is one significant exception. ” “In cases of Meniere’s Disease affecting both ears simultaneously, the administration of streptomycin intramuscularly (injection into the muscle of the arm or buttocks) can cure vertigo attacks and hearing may also be spared.
” “Treatment, of course, affects both inner ears, and leaves the individual with complete absence of balance nerve function, both gyroscopes having been stilled. Most people can adjust to this loss of balance, although they often complain of a “bouncing up and down feeling” when walking. The horizon may also seem to move up and down with their steps. This sensation is called Ossiculopsia. For this reason, the streptomycin injections are only recommended for Bilateral Meniere’s. ” If anything that is defected with the human body as humans we also have the intellect to adapt to our environment.
If I was born blind, my other senses take over to compensate the disability. Same with hearing, changing and adapting to a lifestyle that suits you can cause fewer attacks or even offset the attacks down the line. From either treatment, surgery or just a change to your diet can make a world of difference in someone who has Meniere’s Disease.
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Causes, Diagnosis, Symptoms, and Treatment on MedicineNet. com. ” Meniere’s Disease. Ed. William C. Shiel Jr. , MD. Web. 16 Nov. 2011. “Auditory System. ” Wikipedia, the Free Encyclopedia. Web. 16 Nov. 2011. Alberti, Peter W. “The Anatomy and Physiology of the Ear and Hearing. ” Web 16 Nov. 2011.