15 W. Dry Creek Circle 6169 S. Balsam Way; Suite 290
Littleton, CO 80120-4427 Littleton, Colorado 80123
Phone: (303) 798-1309 Fax: (303) 798-2319
Ear, Nose & Throat Center
Specialists of the Ear, Nose and Throat / Head and Neck Surgery / Facial Plastic Surgery
Evaluation of Dizziness & Vestibular Disorders
For more information see us at our web site ! http://www.ENT Center.Net
Cochlear Hydrops; Atypical Meniere's Disease
It is possible to have fewer than the four classic symptoms of Meniere's Disease (hearing loss, fullness, tinnitus, and vertigo) yet be diagnosed with Meniere's Disease; this is sometimes said to be "atypical" (not typical) Meniere's Disease, of which there are two types. Some Meniere's Disease patients experience hearing loss, fullness, and tinnitus with no vertigo at all, a condition sometimes described as "cochlear hydrops." Some physicians don't consider "cochlear hydrops" to be Meniere's disease at all; other physicians consider cochlear hydrops to be a form of Meniere's disease. Some physicians believe that cochlear hydrops will always progress to Meniere's Disease with vertigo; others do not believe this will occur.
Another group of Meniere's Disease patients experience vertigo with no hearing loss, a condition sometimes described as "vestibular hydrops." A number of physicians don't consider vestibular hydrops to be Meniere's Disease at all; other physicians consider vestibular hydrops to be a form of Meniere's Disease. Some physicians believe that vestibular hydrops will always progress to Meniere's Disease with hearing loss, but other physicians disagree.
The following is a typical presentation of cochlear hydrops. The patient experiences tinnitus for several years. It can follow an episode of loud noise exposure with the onset of tinnitus. Over time the ringing can be accompanied with a feeling of fullness in the ears. The ears can have several "clear" days and then a day or two later the ringing would go away. This pattern can continue for several years; ringing and fullness, a clearing of the ears, and the dissipation of the tinnitus. The condition may progress with the patient unable to "clear" their ears and the tinnitus never resolving. Frequently the condition can be mistaken by the physician as due to transient eustachian tube dysfunction. Steroids, decongestants, and antihistamines generally give no improvement. At times myringotomy tubes have been placed with no benefits being realized. Tubes generally only cause an agitation of the tinnitus although the feeling of fullness persists. On occasion a "big yawn" or valsalva maneuver will cause the feeling of pressure within the ears will vanish for a brief 1/2 second or so, only to return quickly.
The description of these symptoms is similar to what one experiences with eustachian tube dysfunction. Often there are characteristics found on physical examination or on audiometric examination, particularly with tympanogram testing that can differentiate between these two diseases. However, if eustachian tube dysfunction is indeed the cause of the symptoms, one would expect that if it weren't self-limited that the placement of tympanostomy tubes would alleviate or lessen the symptoms.
A less common cause for symptoms such as these include a patulous eustachian tube which is called Autophony. With patulous eustachian tubes, one typically experiences autophonia or a heightened awareness of one's own bodily sounds and voice which may also be associated with a sensation of fullness in the ears. Usually one also experiences audible popping or snapping of the ear drum with each respiration do to unrestrained flow of air back and forth through the eustachian tubes. The latter symptom is easily dealt with in most cases by placement of a tympanostomy tube but the symptom of autophonia is usually refractory to most attempts at treatment.
A rare cause for these types of symptoms can include inflammation of the temporomandibular joint ( TMJ ). Because of similar sensory innervations of the ear and the temporomandibular joint, pain initiated in the temporomandibular joint can be felt to be from within the ear. Ear fullness, otalgia, and perceived fluctuating hearing loss can result from temporomandibular joint inflammation. Observation of a mechanical soft diet, anti-inflammatory medications, and construction of a "bite block" by a qualified dentist or prostadontist to limit jaw excursion and further deformation of the temporomandibular joint will in most cases improve TMJ syndrome.
Cochlear endolymphatic hydrops is an uncommon variant of Meniere's disease. Meniere's disease occurs because of a condition of the inner ear whereby the normal fluids of the inner ear fail to resorb in a timely fashion while fluid continues to enter the channels of the inner ear. This leads to a build up of fluid pressure and eventually, in severe cases, rupture of internal membranes of the inner ear causing attacks of roaring tinnitus, whirling vertigo, and hearing loss. Cochlear variants of Meniere's are thought to exist whereby the fluid accumulation is isolated to the cochlear (hearing) portion of the inner ear without affecting the vestibular (balance) portion. Since the apex of the cochlea is wound much tighter than the base, the apex is more sensitive to pressure changes than the base. This explains why hydrops preferentially affects low frequencies (at the apex) as opposed to high frequencies (at the relatively wider base of the cochlea). Symptoms improve after the membrane is repaired as sodium and potassium concentrations revert to normal. Cochlear hydrops is thought to cause tinnitus, hearing loss, and fullness in the affected ear without dizziness. This pressure accumulation causes the following tetrad of symptoms: 1.) Fluctuating hearing loss (sometimes good or bad), 2.) Episodic vertigo (can be violent), 3.) Tinnitus or ringing in the ears (usually low tone roaring), and 4.) Aural fullness (pressure, discomfort, fullness sensation in the ears).
Frequency:
In the US: Although probably underestimated, approximately 1,000 cases per 100,000 population is reasonable approximation for cochlear hydrops and Meniere's disease. There appears to be familial predisposition since half of patients have a significant family history. There may be a slight female preponderance at 1 to 1.8:1. The mean age among treatment groups in some studies ranged from 49-67 years.
Debilitating Effects:
Although the disease itself is not fatal, there can be significant morbidity. Vertigo can cause accidents and falls, which can be devastating. Hearing loss is often progressive over time. Many patients can no longer work and are forced to claim disability.
History:
The typical history involves episodic attacks of true whirling vertigo, which are usually preceded by a variable sense of ear pressure and fullness, decreased hearing, and a low tone roaring tinnitus. The vertiginous attacks typically last minutes to hours, often associated with severe nausea and vomiting. After the acute attack, patients generally feel tired, unsteady, and nauseated for hours to days. The timing and frequency of attacks is variable. Some patients can regularly predict an attack while others note a completely random pattern. Attacks may be linked to dietary triggers, the menstrual cycle or psychosocial stresses. Between episodes, some patients are completely symptom-free. Many notice progressive deterioration of hearing and balance function with each successive attack.
Physical:
Exam results vary, depending upon the phase of disease. During remission, the physical examination may be completely normal, particularly if the patient is symptom-free. During an acute attack, the patient has severe vertigo. Patients are often in significant distress. Many present to the physician's office clutching a bucket and towel with signs of recent vomiting. Patients are sometimes diaphoretic and pale. Vital signs may show elevated blood pressure, pulse and respiration. Significant nystagmus may be present. Pneumo-otoscopy of the affected ear may sometimes elicit symptoms or cause nystagmus. The Romberg test generally shows significant instability and worsening when the eyes are closed. The Fukuda marching step test may show significant deviation (if the patient can stand with closed eyes). The Dix Hallpike test may be positive, indicating co-existing benign positional vertigo. Hearing is usually affected. The Weber tuning fork test will usually lateralize away from the affected ear. The Rinne test usually indicates that air conduction remains better than bone conduction. It is important to do a complete neurological evaluation. New-onset vertigo might be an early sign of stroke, migraine or brainstem compression that may require emergent evaluation and care.
Causes:
Several disorders may cause increased endolymph pressure, including metabolic disturbances, hormonal balance, and various infections. Autoimmune diseases such as lupus and rheumatoid arthritis may cause an inflammatory response within the labyrinth. Allergy has also been implicated in many cases of "difficult to treat" cochlear hydrops or Meniere's disease.
Workup:
Lab Studies / Blood tests: Several are used to exclude obvious metabolic disturbances, infections, and/or hormonal imbalances. Thyroid stimulatory hormone (TSH), T4, T3, Serum glucose, Sedimentation rate (ESR), Anti-nuclear antibody, Urinalysis (UA) for proteinuria, hematuria or other indicators of otorenal syndrome. Complete blood count (CBC). Electrolytes. FTA-ABS and a VDRL for neuro-syphilis. Allergy testing for allergic mediated Meniere Syndrome. Lyme disease testing
Imaging Studies: Magnetic resonance imaging (MRI) scan. Brain scan to rule out abnormal anatomy or mass lesions. Specifically, acoustic neuromas or other cerebellopontine angle lesions are sought. Other lesions such as multiple sclerosis or Arnold-Chiari malformations can also be ruled out. Note that mass lesions are rarely found but important to exclude. Computed tomography (CT) scans to look for dehiscent superior semicircular canals and/or widened cochlear and vestibular aqueducts
Other Tests: Audiometry is particularly helpful to document present hearing acuity and to detect future change. The patient may not notice a loss at specific frequencies. There may be a low frequency or mixed low and high frequency insufficiency. Typically, the lower frequencies are more severely affected. This is due to preferential sensitivity of the apex to the hydrops. Multiple hearing tests, which document fluctuating hearing loss, are helpful in diagnosing Meniere's. Transtympanic electrocochleography (ECOG) specifically detects distortion of the neural membranes of the inner ear. This is presumably due to perilymph pressure fluctuations and can show evidence for cochlear involvement. ECOG measures the ratio of the summating potential (probably from the movement of the basilar membrane) and the nerve action potential in response to auditory stimuli. Hydrops is suggested when this ratio is greater than 35%. Electronystagmography (ENG) is a test of the inner ear function of the labyrinth (particularly the semicircular canals). Administer the test on an empty stomach and after discontinuing meclizine (Antivert), antihistamines and sedatives for two weeks. These drugs may alter test results. The patient may feel dizzy or nauseated. The test determines inner ear vestibular responsiveness to movement and caloric stimulation. It tests central and peripheral function and can help localize the site of lesion. Typically, endolymphatic hydrops will cause a reduced vestibular response in the affected ear, although there may be an increased response secondary to an irritative lesion. There may be an "irritative" phase during the an attack of Meniere's disease or late cochlear hydrops (fast phases directed toward involved ear) followed by a paretic phase (fast phases directed toward opposite ear).
TREATMENT
The basic treatment measures include avoidance of salt, diuretic therapy, and occasionally short term use of systemic steroids.
Medical Care: Medical therapy is both symptomatic (ie, acute attacks) and prophylactic. If cochlear hydrops is due to a secondary cause primary first line management is the diagnosis and treatment of the primary disease (eg, thyroid disease). To control vertiginous symptoms, vestibulosuppressants (eg, Antivert, Droperidol, Compazine, Valium, Ativan, Xanax) decrease symptoms, but generally only mask the vertigo by decreasing the brain's response to vestibular input. Diuretics or diuretic-like medications (eg, Dyazide, hydrochlorothiazide, Diamox, Neptazane) actually decrease the fluid pressure load in the inner ear by increasing sodium excretion. Maintaining a reduced salt intake to less than 2 grams of sodium intake per day is thought to keep the cochlear pressure low. These medications help prevent attacks but do not help once an acute attack has started. Anti-inflammatory properties of steroids are helpful in endolymphatic hydrops. This is probably due to reduce endolymphatic pressure. Steroids can actually reverse vertigo, tinnitus and hearing loss. Aminoglycosides are a class of antibiotics that were serendipitously discovered to be preferentially toxic to the vestibular end organ. Destruction of the vestibular end organ renders the brain insensitive to the fluctuations the inner ear pressure during an acute Meniere's attack. If given systemically, aminoglycosides will affect both ears. Although it can be used to treat extremely severe bilateral Meniere's Disease, it will leave the patient with little or no balance function. The resulting Dandy's syndrome, a complete loss of inner ear function, can be debilitating. Other routes of administration, in particular, transtympanic injection will be discussed later. During the quiescent phase, medical treatment of cochlear hydrops and/or Meniere's Disease is tailored to each patient. Lifestyle and dietary changes are usually the first step. Avoiding trigger substances (eg, caffeine) alone may be sufficient. Smoking cessation is also recommended. If medications are required, a 3-month trial of a diuretic (eg, Dyazide) and dietary management are prescribed. Typically, vestibulosuppressants and antinausea medications (eg, meclizine, Compazine) are prescribed for p.r.n. use to suppress any vertiginous symptoms. Note that frequent and chronic use of these medications can be deleterious. In an acutely vertiginous patient, management is directed towards vertigo control. IV or IM diazepam provides excellent vestibular suppression and antinausea effects. Steroids can be given for anti-inflammatory effects in the inner ear. IV fluid support can help prevent dehydration and replaces electrolytes.
Surgical Care:
Surgical therapy for cochlear hydrops or Meniere's disease is reserved for medical treatment failures and is somewhat controversial. Historically, there have been several surgical procedures that have been invented, tested, and discarded. Discussion will be limited to the two most generally accepted management options: endolymphatic sac decompression or shunt, and transtympanic medication perfusion. These are most frequently used to control vertigo symptoms.
Endolymphatic Sac Decompression and/or Shunt
In theory, the endolymphatic sac procedure decreases endolymph pressure accumulation by removing the petrous bone, which encases the endolymph reservoir. This procedure allows the reservoir sac to expand more freely, thus dissipating pressure. A drain or valve from the endolymphatic space to either the mastoid or subarachnoid space can be inserted as another means of further reducing pressure. Exposing the endolymphatic sac is essentially an extended mastoidectomy. Special care is taken to skeletonize the sigmoid sinus, posterior fossa dura and posterior semicircular canal. The thin, egg-shelled bone is removed from the posterior fossa dura and sigmoid sinus. The endolymphatic sac is distinguished from dura by color and texture differences. The sac is thicker and more white as compared to the surrounding tissue. The location of the sac can vary, but it is generally immediately posterior or posterior inferior to the posterior semicircular canal. In endolymphatic sac decompression, the procedure is terminated after all of the bone overlying the sac is removed. The shunt procedures involve incising the lateral leaf of the sac and inserting a drainage tube into the internal lumen of the endolymphatic duct. As aforementioned, the shunt can either drain into the subarachnoid space or the mastoid space.
Success rates (in terms of controlling vertigo and stabilizing hearing acuity) are reported at 60-80%. There does not seem to be a tremendous difference in success rates between endolymphatic sac decompression alone and those coupled with shunt procedures. Morbidity and mortality of endolymphatic sac decompression are relatively low. The risk of hearing loss and facial nerve damage is minimal in experienced hands. Severe postoperative pain is unusual, in which case the recovery period is typically short and uneventful. The endolymphatic sac procedure is one of the most controversial issues in otolaryngology. Citing the famous Danish study, critics argue that endolymphatic surgery is no more effective than sham surgery and that any benefit is due to placebo effect. Proponents argue that patients indeed improve and compared to destructive procedures, the endolymphatic sac procedures have low risk and morbidity. These procedures may provide relief in patients who have failed medical therapy.
Transtympanic Perfusion Of Medication
Transtympanic perfusion of medication is a relatively new modality of treatment. This is used mostly to control dizziness associated with Meniere's disease. Popularized by Dr. John Shea in 1995, the procedure is still evolving and although there are variations, the concept remains the same. Medications for Meniere's disease or cochlear hydrops are applied through a myringotomy within the middle ear cavity, where it is presumably absorbed through the round window membrane into the inner ear. Transtympanic perfusion is a relatively low-risk, simple procedure that applies a high concentration of medicine with minimal systemic effects. It is similar to the placement of tympanostomy tubes, which can be done in the office or on an outpatient setting. Recent innovations such as the round window microcatheter have been designed to direct the flow of medication directly to the round window niche. This method theoretically reduces dosing inconsistencies due to wastage down the Eustachian tube. It also allows for slow, continuous micropump infusion. If steroids are administered with this transtympanic technique, the surgery is classified as nondestructive. Transtympanic steroid application is useful, particularly when patients have poor tolerance for the systemic side effects of steroids. A higher concentration can be obtained using this approach. Success rates seem favorable, although long-term studies are unavailable. If aminoglycosides are used, the surgery is classified as destructive. When given transtympanically, aminoglycosides can concentrate their effects in the affected ear. Since streptomycin is difficult to obtain in the United States due to FDA restrictions, gentamicin is more widely used. Early studies show about 90% efficacy. Some authors report significant worsening of hearing in 5-15% of patients.
Diet: Dietary management is appropriate in patients not severely affected (ie, avoiding substances that may trigger or exacerbate fluid pressure buildup in the inner ear). Similar to managing systemic hypertension, the goal for cochlear hydrops is to reduce the total body fluid volume. This, in turn, may reduce the inner ear fluid volume. Since sodium seems to play a major role in fluid retention within the inner ear, avoiding salt (eg, pizza, preserved foods, smoked fish) is paramount. Consult with a nutritionist to establish a rigid salt-restricted diet (1.5 g sodium per day). Avoiding other trigger substances (eg, caffeine, nicotine, alcohol, high-carbohydrate substances, high-cholesterol/triglyceride foods) can also help. Note that many preserved and smoked foods contain sodium nitrate which can contribute to high sodium content.
Activity: Endolymphatic hydrops does not preclude regular activity. Exercise is recommended in moderation. Due to the unpredictable nature of the disease balance-intensive, dangerous tasks (eg, especially climbing ladders) should be avoided.
Follow-Up: Aside from acute control of vertigo and associated effects (eg, dehydration from protracted vomiting), inpatient care is generally unnecessary.
Further Outpatient Care: Vestibular rehabilitation can be helpful in teaching patients to cope with vertigo and imbalance.
Deterrence/Prevention: Dietary control and avoiding trigger substances
Prognosis: Prognosis is variable since the disease pattern of exacerbation and remission makes evaluation of treatment and prognosis is difficult to predict. In general, Cochlear hydrops patients tend to stabilize spontaneously with time. With regard to fluctuating hearing loss about half of patients stabilize over several years. Patients tend to "burn out" over time and with residual poor hearing. Cochlear hydrops is most bothersome during the early stages. As patients progress to later stages, the hydrops fills the vestibule and cochlea so completely that there is no further room for pressure fluctuation. The acute attacks are replaced by progressive hearing loss and possibly advancement into vertigo.
Patient Education: Proper education in terms of dietary control and avoidance techniques are helpful. Hearing loss should be corrected with hearing aid amplification where necessary. If vertigo is also present ( extending into true Meniere's disease ), vestibular rehabilitation can be helpful in teaching patients to cope with the vertigo and imbalance. You should consult with an otolaryngologist. This is an ear, nose throat specialist who has training in conditions of the ear and balance.
