Tinnitus: Noises in the head
Tinnitus could be responsible for the incessant noises in your head. But information and determination can help get things under control, writes Sheila Kumar
All of us hear noises inside our heads at one time or the other. For most of us, it is a fleeting phenomenon. But for others, these noises affect hearing. Different people hear different sounds. It could be bells ringing, waves at sea, water rushing, humming, clicking, shrill whistling, a pulsated roar, sound of a helicopter, the sizzle of an egg frying, the buzz of a doorbell, all the time. This aural affliction is called tinnitus. It refers to the conscious experience of sound originating in the head of the person in the absence of an objective source. In short, it's a phantom auditory experience.
Ongoing studies by the US-based Tinnitus Research Consortium and the American Tinnitus Association have pegged tinnitus sufferers worldwide at 100 million, and counting. Many hear noises only occasionally but as many as 10 million afflicted people hear noises loudly, affecting their lives daily. They spend their days worrying about the noises; they spend sleepless nights worrying about possible tumours inside the brain.
SOURCE OF SOUND
Till the 1980s, it was believed that tinnitus was a result of damaged inner ear. However, most experimental research could not substantiate this claim. Studies by the Tinnitus Research Consortium and the American Tinnitus Association have now established that it is often a reaction to medication, food allergies, diabetes, heavy smoking and excessive alcohol intake. Foreign objects lodged in the ear, nerve damage or irritation, middle-ear infections that at any time in life could have damaged the ear, and severe wax build-up can also lead to tinnitus. At times, blood rushing through an injured vein causes a ringing sound.
Another cause is hearing loss because of ageing, when the membrane within the ear canal dries out. Almost all sufferers have had some degree of hearing loss. And in many cases, when that aspect is dealt with, the tinnitus may dramatically vanish or decrease in intensity.
Professionals who are exposed to some amount of loud noise at their workplace (hangar mechanics, pilots, welders, drillers) also suffer from tinnitus at some point in their lives. Patients report an increase in tinnitus when they suffer from headaches or are otherwise stressed; in such cases, ringing becomes a veritable roar.
"Understanding how our brain reacts to noise is vital," says Delhi-based ENT surgeon Lt Col Sabari Girish. "The brain usually takes in some noise from the environment and classifies it as potentially threatening, neutral or non-threatening. That message gets passed down and the body reacts in an active, alert or passive manner. In the case of tinnitus, as the brain cannot relate the noise to any previously classified noise, it will classify it as threatening and send frissons of alarm racing inside your head. This puts your mind and body on an adrenaline high. Insomnia depression, anxiety and panic attacks are some of the problems tinnitus sufferers fall prey to."
Research has also shown that after five minutes in a soundproof room, 94 per cent of normal individuals experience tinnitus. Their description of sounds they hear match exactly with those with pathological tinnitus. This shows that almost anyone can detect background electrical activity present in every living nerve cell in the hearing pathways as a sound. These signals are not evidence of damage to the inner ear, as believed earlier, but compensatory activity that occurs all the time in our auditory systems. Compensation can occur as a response to changes in our sound environment (like silence) to hearing loss. It's good to think of the sounds produced by this compensatory activity as `the music of the brain'.
"In some cases, tinnitus is a symptom of cardiovascular disease, abnormalities in the blood vessels of the brain, Meniere's disease [disorder of the inner ear], anaemia, aneurisms, acoustic trauma, and tumours in the head," adds Dr Girish. "If nausea, dizziness, rapid breathing, vertigo or unsteadiness in walking, difficulty in hearing and hallucinations accompany tinnitus, patients must take aural tests and an MRI to rule out anything serious."
Even today, most treatment is based on the theory that it is a result of damage to the inner ear. Pharmacological agents are still being used with no scientific evidence for their efficacy. These include lignocaine (a local anaesthetic), vitamins, minerals, and ginko biloba (an extract from the Chinese herb ginseng).
"All patients must first have a thorough otological and audiological examination," says Dr Reginald Varadarajulu, a Bengaluru-based neurologist. There are many instances where auditory imagery could include hymns or jingles. These may be confused with psychotic disorders like schizophrenia. If there are additional symptoms, a complete neurological examination may be appropriate. "A person with an isolated symptom of an unexplained tinnitus should receive follow-up exams when initial studies reveal no evidence of disease," he adds.
Effective medications include drugs like carbamazepine and intravenous lidocaine or barbiturates, but Varadarajulu reveals that these may have serious side effects. Another method is to manage tinnitus with masking - it has met with mixed success. Maskers introduce an external masking sound into the affected ear, minimising or eliminating the perception of tinnitus. However, their efficacy is less than 30 per cent. According to Varadarajulu, a hearing aid may be beneficial by addressing the primary hearing problem and masking tinnitus.
If tests, including MRI, are clear, the patient needs to accept that tinnitus cannot be cured - only managed. Most specialists expect patients to learn to live with it.