Mary was late for an office meeting one Wednesday morning. She tried to call her work mate to tell him that she couldn't make it on time, but there was no answer. Her dog was by the door, she could tell that it's barking at her, but there was no sound. By then she knew that something's not right, that neither the phone nor the alarm clock were busted, she just didn't hear it go off. Realizing that she woke up deaf, Mary head to her doctor immediately.
This is a rare case of Sudden Sensorineural Hearing loss (SSHL). An abrupt state of deafness that usually occurs in one ear, with only 2% of patients develop having bilateral hearing loss. Left and right ears are equally susceptible and the recovery varies from one person to another. It is usually accompanied with dizziness or vertigo, aural fullness, ringing in the affected ear (Tinnitus), and an occasional incidence of upper respiratory infection (cold symptoms). Both men and women are equally vulnerable and the average onset appear between ages 46 to 49 years, with the rate of its occurrence increasing with age.
Sounds heard by human ears are measured in two ways: Decibels (dB) which measures the intensity or the loudness of sound, and frequencies which measure sound waves to help determine the difference between the pitch of one sound from that of the other. In the case of SSHL, there is a reduction of hearing greater than 30 decibels (which is half as loud as a normal conversation) in three contiguous frequencies, which lasts over a period of three days or less.
For the majority of Sudden Sensorineural Hearing loss (SSHL) patients, the cause is idiopathic and only a few percent have been conclusively diagnosed. There are unexpected cases, like, the person just simply went to bed hearing and woke up deaf -a situation where hearing loss is believed to have developed instantly or progressively with in the hours of sleep. Some may have gotten the condition from events such as, exposure to very loud sounds, excessive strain from lifting heavy objects, sudden change of pressure from flying or scuba diving, trauma to the head, previous surgery, recent respiratory tract infections, circulatory problems, or from medications like ototoxic drugs. Other potential origins of hearing loss includes multiple sclerosis, Buerger's disease, luekemia, sickle cell disease, syphilis, bacterial infection, lupus, mumps, measles or chicken pox. Even after doing numerous researches about the etiology of SSHL, its cause still remains unknown in most patients.
Basing from the patient's complain, initial assessment for SSHL starts with analysis of medical history and thorough physical examination to look for possible infectious causes. Patients perform hearing tests conducted by an audiologist inside a sound proof chamber. Tests include speech discrimination scores, Pure-tone threshold, acoustic reflex testing, and otoacoustic emission testing. All of these audiometric evaluations are then carefully documented to confirm diagnosis. Laboratory based studies are conducted depending on the patients history and probable etiology. Blood examinations are made to determine the possible existence of systemic causes such as syphilis, metabolic and circulatory disorders. Magnetic Resonance Imaging (MRI) is also done to rule out possible lesions or tumors such as acoustic neuroma, which is reported to be present among 15% of SSHL patients.
Treatment for SSHL is dependent upon the patient's etiology. Some may just be given simple advice, merely refraining from doing stuff that are considered as contributory factors of hearing loss; like avoid doing strenuous activities and stop taking drugs that may harm the ears. Surgical interventions may be given to those with existing tumor in the ear. In some cases, patients are given rehabilitation appointments, through which the use of hearing aids and other assistive listening devices are introduced. But among all these, the most common therapy given for SSHL, especially for patients with idiopathic cause, is steroid treatment. Taking steroids with in the first 2weeks from the onset of symptom provides the best chances of hearing to return. Oral intake is the common way to do it but steroids injected directly into the ear/ears may also be beneficial.
The improvement of hearing loss in SSHL varies in every individual. Patients may undergo spontaneous recovery, may stabilize, fluctuate, or become more severe depending on its underlying cause and medical intervention. There is a good to excellent scale of recovery among most patients, with only about 15% experiencing hearing loss that gets worse over time. But still, It is important to know that once the symptoms appear it should then be regarded as a medical emergency. An immediate appointment with a physician must be done the soonest possible time. If a delay in treatment occurs (48 hours or more from the time the symptoms appear), the effect of medications to help improve hearing loss, will decrease. Great caution should be observed -- the earlier the medical help, the greater chances of recovery.
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