Is It Tinnitus?
By Murray Grossan, MD
Editor: People with hearing loss routinely talk about their tinnitus. But is what a particular person has really tinnitus? You may be surprised by the answer, and you’ll learn something about objective tinnitus, subjective tinnitus, and false tinnitus along the way. Thanks to bhNEWS for this article, which originally appeared in “Advance for Audiologists”.
Although tinnitus is defined as a subjective sensation of a sound heard by the patient but which cannot be recorded or otherwise detected by any means, sometimes there are underlying physical causes that cause the sound. When these causes can be perceived by another person, the tinnitus is termed “objective;” when only the patient can hear the sound and no underlying causes can be identified, the tinnitus is termed “subjective.”
Diagnosis requires careful evaluation because other conditions can cause symptoms that mimic tinnitus, and patients often mistake and mislabel other conditions as tinnitus.
Objective tinnitus occurs when certain blood vessels become noisy. This can be due to an aneurism near the ear, hardening of a blood vessel, pressure on a vessel caused by a shunt or other implanted device, or enlargement of a vein or artery near the ear. The most common characteristic of objective tinnitus is that it sounds like a beat or throb and matches the pulse. It can be detected in OAE testing. Objective tinnitus can occur suddenly and may be temporary because it can accompany elevated blood pressure; when the blood pressure is reduced, the tinnitus may stop as suddenly as it started. If a patient complains of a sudden onset of tinnitus, ask about their blood pressure history.
In theory, with all our modern techniques for visualizing blood vessels and circulation to the brain, identifying the offending vessel should be possible, and then the problem can be corrected. In practice, however, identification has proven to be difficult in many cases.
Another cause of objective tinnitus is a glomus jugulare tumor, which involves the jugular vein as it courses beneath the middle ear. When the vein fills into the floor of the middle ear, the patient hears a sound that matches the pulse, and hearing is also affected. In looking at the tympanic membrane, often you can see a bluish dome that represents the dilated vein of this lesion.
If a patient claims to have tinnitus, describing, “When I yawn or eat it gets worse,” perhaps the patient actually has temporomandibular joint disorder (TMJ). Look at the jaw when the patient opens the mouth. Does it open midline, or zigzag or jut severely to one side? Place your index fingers into both joints and ask the patient to chew. You may be able to feel and hear crepitation; heard by the patient, this sound often can be mistaken for tinnitus. Your finger pressure may also reveal that one of the joints is painful. Understanding TMJ is important to the audiologist for other reasons because it also can cause patients to complain of pain when using a hearing aid.
A patent eustachian tube can cause false tinnitus symptoms. Here the eustachian tube is wide open, causing a distressing alteration of sound that can be aggravated by nasal breathing. Don’t blame the patient for mislabeling this condition as tinnitus-it is actually hard to describe. Unfortunately, it is hard to correct as well. One method is to inject a filler to partially close the opening.
Hyperacusis is often mistaken for tinnitus. In this condition, ordinary loud sounds are “too loud” and feel painful and upsetting, but the “tinnitus” goes away in quiet. Subjective tinnitus differs in that it is louder in quiet.
Where English is a second language, it is more difficult to understand a complaint of tinnitus. Patients can mistake headache, drug reaction, fatigue, hypertension, flu, and even depression as tinnitus.
The audiologist is in the best position to help patients with tinnitus symptoms understand those symptoms and relieve the anxiety that may accompany them. But practitioners must first answer the question, “Is it tinnitus?”
Tinnitus Case Study
Mrs. C, age 49, was mildly overweight and hypertensive, but not diabetic. She awoke at 3 a.m. with very loud tinnitus in her right ear. She thought it might be an alarm or siren. When it persisted, she thought it might be an insect in the ear and asked her husband to look with a flashlight. He didn’t see anything. By 4 a.m. she couldn’t stand it any more, and her husband drove her to the emergency room. There, the doctor was concerned about stroke. Mrs. C was hypertensive and taking medication, but her blood pressure was 145/95. Fearing a stroke, the ER doctor sedated Mrs. C, brought the blood pressure down and put her to sleep. By 11 a.m., an MRI of the brain had been done, but it showed no abnormalities. The ER doctor recommended carotid artery visualization, but the patient, after an explanation of what would be involved, opted to forgo the procedure and instead seek further treatment on her own.
She consulted a local ENT, who reviewed Mrs. C’s history and examined her. Her ears were normal; an audiogram showed a mild high tone drop off but was symmetrical. He carefully checked for nystagmus and watched her walk, but there were no signs of dizziness. Mrs. C also exhibited no signs of facial nerve weakness. She did show a slight crepitation in both temporomandibular joints, but reported no pain. The doctor prescribed one of the heavily advertised herbal medications and asked Mrs. C to return in a week.
When she returned, there was little improvement. The doctor reviewed her medications and checked her blood pressure, which had dropped to 129/86. Mrs. C. stated that the tinnitus was a little bit better than at its onset but was still so distressing that she was unable to do her work as an accountant.
A week later, Mrs. C consulted another ENT doctor. He repeated the ENT and neurologic exams and performed another audiogram. There was no change in the audiogram. The doctor asked if there was a sensation of fullness in the right ear; Mrs. C said there was not. The practice’s audiologist then performed a tinnitus match; it was matched at 6,000 Hz at 15 decibels below the 25 db hearing level of 6,000 Hz. The doctor diagnosed cochlear hydrops, to be treated with a carbonic anhydrase inhibitor-Methazolamide-and a low-salt diet to include distilled water.
In a week, Mrs. C was significantly improved. A repeat audiogram showed no improvement in the audiogram but a significant reduction in the volume of tinnitus. The doctor continued her on the above regimen.
Meniere’s disease is cochlear hydrops that reoccurs. Both conditions are characterized by fullness of the ear, hearing loss, dizziness and tinnitus. The patient may be awakened by any one or more of these symptoms. Since Mrs. C had no prior episodes, she couldn’t have Meniere’s.
How could the diagnosis of hydrops be made with only one symptom? In this case it was possible because the tinnitus awakened her out of a sound sleep, it persisted and other etiologies of stroke-increased cerebrospinal pressure and hypertension-had been ruled out. Her response to the treatment confirmed the diagnosis.
The elevated blood pressure in the emergency room had been caused by anxiety and was not a causal factor of her symptoms. Salt, however, proved to be problematic for Mrs. C.
Taking her medication and following a low-salt diet, she did well for two more weeks and then stopped taking the Methazolamide. Six weeks later she attended a party and unconsciously ate heavily salted snacks. The next day, her tinnitus returned with dizziness and a low tone hearing loss, all in the right ear. Now she felt a pressure in that ear. Fortunately, she responded to therapy.
Even though she had a recurrence of hydrops symptoms, her condition was not classified as Meniere’s because the incidents were close enough to perhaps be part of the initial diagnosis. If in 3 months or more the hydrops reoccurs, then it would be classed as Meniere’s.
Murray Grossan, MD, practices at Cedars Sinai Medical Towers in Los Angeles. His complete biography is available at www.ent-consult.com. Contact him at firstname.lastname@example.org.