Meniere’s disease: differential diagnosis and treatment – includes patient information sheet
Glenn W. Knox
Meniere’s disease is characterized by four distinct symptoms: fluctuating sensorineural hearing loss, classically involving the low frequencies; vertiginous episodes; aural pressure, and tinnitus that is most frequently described as roaring. Any one of these symptoms may precede the others, but they characteristically appear together.
Meniere’s disease occurs fairly equally in men and women, with symptoms usually developing in the fifth decade of life. Rarely, the disease is diagnosed in children. Approximately 30 percent of patients with Meniere’s disease have bilateral involvement. Because of the inconsistency in establishing the diagnosis, the true incidence of the disease is unknown. However, it is estimated that 300,000 new cases develop each year.
Early in the course of Meniere’s disease, the primary complaint is an episodic vertigo that lasts from minutes to hours and is associated with nausea and vomiting.’ Most commonly, aural pressure, fluctuating tinnitus and fluctuating hearing loss accompany the vertiginous episodes. The dizziness or vertigo is most often described as a sensation of whirling or of the room spinning. During the active phase of Meniere’s disease, patients can have more than 30 attacks of vertigo a year. In the later phase of the disease, the audiometric pattern is flat but slightly worse for the very low and high frequencies, and there is no fluctuation in audiometric findings and/or subjective hearing.
When Meniere’s disease presents with isolated auditory (cochlear) or vertiginous (vestibular) components, the differential diagnosis becomes very important, since dizziness is the presenting complaint in a number of disorders. In addition to Meniere’s disease, the most common diagnoses related to dizziness include benign paroxysmal positional vertigo, vestibular neuronitis, vertebrobasilar insufficiency, atherosclerosis, presbystasis, acoustic neuroma, vertiginous or basilar artery migraine, and head trauma syndrome (Table 1). Dizziness is a symptom of various other medical problems, including (but not limited to) syphilis, impaired thyroid function, hypoglycemia, anemia, cardiogenic disorders and incompletely treated Lyme disease. Other central nervous system causes of dizziness include brain tumors, demyelinating disorders and cerebellar infarcts.
[TABULAR DATA 1 NOT REPRODUCIBLE IN ASCII]
The patient’s description of the dizziness is extremely important. Lightheadedness or wooziness is distinct from spinning vertigo, although both may be described as dizziness. Spinning or whirling vertigo is characteristic of Meniere’s disease, benign paroxysmal positional vertigo and the earliest stage of vestibular neuronitis.
DIZZINESS CHARACTERIZED AS SPINNING OR WHIRLING VERTIGO
Benign Paroxysmal Positional Vertigo. This condition is characterized by whirling vertigo without other aural symptoms. Dix-Hallpike or positional testing, which is used to diagnose this condition, can be performed in the office. In classic benign paroxysmal positional vertigo, dizziness is elicited by turning or hanging the head to the affected side. It is theorized that the dizziness associated with this condition is caused by the displacement of crystals (i.e., otoliths) from the utricle. The canalith repositioning procedure is used to realign the crystals and to treat the dizziness.
Vestibular Neuronitis. An upper respiratory tract infection usually precedes vestibular neuronitis. The etiology is thought to be viral. In its acute phase, vestibular neuronitis is associated with severe vertigo that lasts for hours to days. The vertigo then resolves to constant imbalance or lightheadedness, which can persist for months in some cases. Daily quality of life is severely affected. No other aural symptoms occur. In intractable cases, benzodiazepines or antihistamines are sometimes used.
Viral Labyrinthitis. This disorder mimics vestibular neuronitis, but hearing loss also occurs. Viral labyrinthitis, like vestibular neuronitis, resolves slowly over weeks to months. Some resolution of hearing occurs concomitantly with the resolution in dizziness.
Vertebrobasilar Insufficiency and Atherosclerosis. These conditions can also cause dizziness. Vertebrobasilar insufficiency is suspected when a patient has dizziness while leaning the head backward, possibly reducing blood flow to the brainstem. The diagnosis of vertebrobasilar insufficiency and/or atherosclerosis can be difficult and often depends on the exclusion of other disorders. The diagnosis can be supported by a history of atherosclerosis in other vessels, as well as compatible findings on imaging studies, such as magnetic resonance angiography or ultrasonography of the neck vessels.
Vertiginous Migraine. This disorder is characterized by vertigo in combination with either a classic or atypical migraine pattern. In basilar artery migraine, transient reduction of basilar artery blood flow produces a variety of symptoms, including ataxia, vertigo, tinnitus, nausea and headache. Basilar artery migraine may also produce diplopia, dysarthria, paresthesias or a throbbing occipital headache. In addition, fluctuating fullness and hearing loss may occur, but tinnitus is rare. Like all migraines, those involving the basilar artery are associated with a strong familial tendency and tend to occur more frequently in females.
For any of the disorders that have a peripheral vestibular component, a course of physical therapy with an emphasis on vestibular rehabilitation may be helpful.
DIZZINESS CHARACTERIZED AS LIGHTHEADEDNESS
A patient may characterize the symptom of dizziness as lightheadedness rather than true vertigo. The disorders associated with this type of dizziness are presbystasis, acoustic neuroma and, in some cases, head trauma syndrome.
Presbystasis. A degeneration of the vestibular system that occurs with aging, presbystasis should not be confused with orthostasis of aging, which may be accompanied by lightheadedness with standing or walking. Imbalance and slight gait disturbance are common symptoms of presbystasis. Presbystasis may or may not be accompanied by degenerative hearing loss. Physical therapy is the treatment of choice, especially when gait disturbance predominates.
Acoustic Neuroma. This benign tumor of the eighth cranial nerve typically causes gradually progressive imbalance and hearing loss on the affected side. Asymmetric hearing loss would be considered suspicious and should be evaluated with either a brainstem auditory evoked response test or magnetic resonance imaging (MRI) for the purpose of ruling out a tumor.
Head Trauma Syndrome. In this syndrome, dizziness develops weeks to months after head injury. Head trauma syndrome, which is very common after motor vehicle accidents, is thought to be the result of diffuse axonal damage. In addition to dizziness, patient complaints commonly include tinnitus, slightly impaired cognitive ability (especially visual and auditory memory and tasking) and headache. The symptoms persist for a considerable period. Occupational and physical therapies are the most effective treatments.
Head injury with or without fracture of the temporal bone may result in a dramatic loss of equilibrium. It is becoming increasingly evident that much of the vertigo that occurs after head injury may have its origin outside of the labyrinth. Marked ecchymosis and edema of the brainstem, cerebral cortex and cerebellar cortical areas may be present. While Meniere’s disease may occur following head trauma, such patients commonly have a mixed type of vertigo with both central and peripheral components. Surgery is less effective in these patients, as it only addresses the peripheral component. Hence, surgery should only be undertaken in cases in which the peripheral component predominates.
IDIOPATHIC MENIERE’S DISEASE
Most cases of Meniere’s disease are classified as idiopathic, and the diagnosis is based on the exclusion of other pathologies. The appropriate evaluation includes a history, a head, neck and neuro-otologic evaluation, audiometry, a vestibular evaluation that includes caloric testing, certain laboratory blood tests and a radiographic evaluation. Metabolic tests often include serum electrolyte levels, a serologic test for syphilis, thyroid function tests, allergy testing and a lipid profile, and MRI may be indicated to rule out acoustic neuroma in selected cases. In recent years, electro-cochleography has been used extensively in the diagnosis of Meniere’s disease. The chief electrocochleographic finding is the ratio of the summating potential to the action potential. This ratio is increased in Meniere’s disease.
Meniere’s disease is difficult to treat. Since few controlled studies have been performed, therapy is largely empiric. Nutritional therapy, which is often tried initially, includes restrictions on the use of sodium, caffeine, alcohol and tobacco.
Drug therapy is used to relieve the nausea and vomiting that accompany acute vertiginous episodes, as well as to control or arrest the disease process. Along with sodium restriction, medical therapy usually includes a diuretic such as triamterene (Dyazide, Maxzide) or a carbonic anhydrase inhibitor such as acetazolamide (Diamox). Benzo-diazepines, such as lorazepam (Ativan) and diazepam (Valium), and antihistamines, such as meclizine (Antivert, Bonine), are commonly used.
During acute attacks, antivertiginous medications are used to relieve vertigo. Promethazine (Phenergan) is sometimes used to quell the nausea and vomiting in vertiginous episodes. Tricyclic antidepressants can be tried in resistant cases.
Although controversial, surgical treatment can be considered in patients with severe, refractory Meniere’s disease. Endolymphatic sac procedures attempt to reestablish the function of the sac as the absorptive organ for the endolymph of the middle ear. In all procedures, a mastoidectomy is performed. The sac can be merely decompressed, or it can be opened. Silastic sheeting or another shunt device is then inserted into the lumen of the endolymphatic sac and allowed to drape into the mastoid cavity. The endolymph that is drained by the shunt is reabsorbed by the mucous membranes of the mastoid cavity.
Endolymphatic sac surgery is, however, highly controversial. The fluid spaces involved are minuscule, and it is doubtful that mechanical means can improve the function of the sac. In 1984, one group reported the results of 405 endolymphatic sac procedures.[9,10] Overall, 65 percent of patients had complete control of vertigo at three years, but only 50 percent of patients had complete control at 10 years.
One double-blind study examined the placebo effect in the reporting of sac surgery results by comparing 15 patients who underwent endolymphatic-mastoid shunt placement with 15 control subjects who had a simple mastoidectomy. Control of vertigo was reported by 70 percent of the persons in each group. A long-term follow-up report showed that the patients in both groups maintained 70 to 80 percent control of vertigo at six years, with no difference in hearing between the two groups. Based on these findings, the authors concluded that there was an indisputable placebo effect in patients’ subjective reporting of vertigo following an operation designed to control vertigo.
Another study compared endolymphatic sac decompression with mastoid shunt surgery for the control of vertigo. In this study, 53 patients with Meniere’s disease were randomly divided into three groups. Endolymphatic sac decompression was performed in the first group, incision of the sac was performed in the second group, and Teflon film was inserted in the endolymphatic sac in the third group. Drainage of the sac did not affect vertigo control. A more recent study compared the effects of decompression and complete excision of the endolymphatic sac. No significant difference was found between the results of this procedure and the results of endolymphatic decompression. Because of the uncertain efficacy of endolymphatic sac surgery, all patients with serviceable hearing must be evaluated individually to determine if they are likely to benefit from the procedure.
Labyrinthectomy is indicated in patients without serviceable hearing in the diseased ear, as well as in elderly or infirm patients who are unable to tolerate a more extensive neuro-otologic procedure. In transmastoid labyrinthectomy, all neuroepithelial elements of the vestibular end organ are removed, resulting in total hearing loss on the operative side. Several studies show complete or marked relief of vertigo in over 90 percent of cases.[15-17]
Vestibular neurectomy or labyrinthectomy should completely relieve vertiginous attacks, because each of these procedures totally eliminates vestibular input from the operative ear. The loss of all vestibular function on one side can easily be compensated for by an intact labyrinth on the opposite side. When the hearing is worth preserving (i.e., a speech reception thresh-old greater than 60 dB and a speech discrimination greater than 40 percent), the procedure of choice is vestibular neurectomy via the middle fossa or the posterior fossa.
Recovery after middle fossa craniotomy is prompt. Unless significant vestibular symptoms are present, patients are usually out of bed and walking the day after surgery. While cerebrospinal fluid leakage is unlikely to occur following this procedure, patients should be checked for both external leakage and leakage down the eustachian tube into the nasopharynx.
Meniere’s disease is not a fatal illness, and affected persons can expect to have a normal life span. However, the debilitating symptoms of the disease may adversely affect the quality of life and may be frustrating for both patients and health care providers. The severe disability that can occur in patients with bilateral Meniere’s disease can have an enormous impact on the lives of these patients and their families.
REFERENCES[1.] Schuknecht HF. Pathology of the ear. Cambridge Mass.: Harvard University Press, 1974.[2.] Boles R, Rice DH, Hybels R, Work WR. Conservative management of Meniere’s disease: Furstenberg regimen revisited. Ann Otol Rhinol Laryngol 1975;84: 513-7.[3.] Arenberg IK, Balkany TJ, Goldman G, Pillsbury RC 3d. The incidence and prevalence of Meniere’s disease–a statistical analysis of limits. Otolaryngol Clin North Am 1980;13:597-601.[4.] Paparella MM, DaCosta SS Fox R, Yoon TH. Meniere’s disease and other labyrinthine diseases. In: Paparella MM, Shumrick DA, Gluckman JL, Meyerhoff WL, eds. Otolaryngology. Philadelphia: Saunders, 1991:1689-1714.[5.] Bernard ME, Bachenberg TC, Brey RH. Benign paroxysmal positional vertigo: the canalith repositioning procedure. Am Fam Physician 1996;53:2613-6.[6.] Schuknecht HF. Pathology of Meniere’s disease as it relates to the sac and tack procedures. Ann Otol Rhinol Laryngol 1977;86:677-82.[7.] Haid CT, Watermeier D, Wolf SR, Berg M. Clinical survey of Meniere’s disease: 574 cases. Acta Otolaryngol Suppl (Stockh) 1995;2:251-5.[8.] Hall JW. Handbook of auditory evoked responses. New York: Allyn and Bacon, 1992:223.[9.] Glasscock ME 3d, Gulya AJ, Pensak ML, Black JN Jr. Medical and surgical management of Meniere’s disease. Am J Otol 1984;5:536-42.[10.] Glasscock ME 3d, Kveton JF, Christiansen SG. Current status of surgery for Meniere’s disease. Otolaryngol Head Neck Surg 1984;92:67-72.[11.] Thomsen J, Bretlau P, Tos M, Johnsen NJ. Placebo effect in surgery for Meniere’s disease. A double-blind, placebo-controlled study on endolymphatic sac shunt surgery. Arch Otolaryngol 1981;107: 271-7.[12.] Thomsen J, Bretlau P, Tos M, Johnsen NJ. Endolymphatic sac-mastoid shunt surgery. A nonspecific treatment modality? Ann Otol Rhinol Laryngol 1986;95:32-5.[13.] Shambaugh GE Jr. Decompression of the endolymphatic sac for hydrops. Otolaryngol Clin North Am 1968;l:613-21.[14.] Welling DB, Pasha R, Roth LJ. The effect of endolymphatic sac excision in Meniere’s disease. Am J Otol 1996;17:278-82.[15.] Kemink JL, Telian SA, Graham MD, Joynt L. Transmastoid labyrinthectomy: reliable surgical management of vertigo. Otolaryngol Head Neck Surg 1989;101:5-10.[16.] Graham MD, Colton JJ. Transmastoid labyrinthectomy indications. Technique and early postoperative results. Laryugoscope 1980;90:1253-62.[17.] Graham MD. Transmastoid labyrinthectomy: further experience with the indications, complications and early post-operative results. J Laryngol Otol 1981;95:1205-11.
GLENN W. KNOX, M.D. is director of the Balance Center at the University of Pennsylvania Medical Center, Philadelphia. Dr. Knox received his medical degree from the Robert Wood Johnson Medical School, Piscataway, N.J. He also completed a fellowship in otolaryngology at Vanderbilt University School of Medicine, Nashville, and a fellowship in neurotology at Baylor College of Medicine, Houston.
ANASTASIA MCPHERSON is a medical writer and editor who works as an administrative assistant and a research assistant at the University of Pennsylvania Medical Center.
Address correspondence to Glenn W. Knox, M.D., Department of Otorhinolaryngology, University of Pennsylvania Medical Center, 3400 Spruce St. (5 Ravdin), Philadelphia, PA 19104.
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