Treatment Options for Meniere's Disease

Surgical Therapy for Meniere's Disease

Patients who have intractable vestibular symptoms (imbalance) and unremitting attacks of vertigo even after treatment with medication are usually considered candidates for surgery. While surgery may help vertigo, it is not associated with improvement in hearing, tinnitus, or aural fullness. The goal of surgery for Meniere's disease is to relieve vertigo while preserving hearing as much as possible. The risks of surgical treatment, especially the potential for exacerbating hearing loss, must be weighed against the severity of distress caused by the vertigo attacks. Some of the risk factors that a patient must consider before choosing one type of surgery over another include:

  • Level of residual hearing in the affected ear
  • Level of hearing in the contralateral ear
  • Intensity of vertigo
  • Surgical outcomes
  • Postsurgical quality of life
  • Age
  • Health status

Regardless of the surgical procedure the patient may ultimately choose, it is of utmost importance that they choose a neurosurgeon or otologic (ear) surgeon who has considerable experience with that particular procedure. The lowest complication rates of surgical procedures are associated with highly trained surgeons and medical institutions that have experience caring for patients that undergo that procedure. Currently, there are no universally accepted guidelines regarding which surgical procedure should be performed before trying another and recommendations are based typically on the experience of the surgeon or otolaryngologist, risk factors mentioned above, and patient preference.

There are two basic types of surgical procedure used to control vertigo attacks in patients with Meniere's disease:

  • Conservative surgical procedures
  • Ablative (destructive) procedures

Conservative Surgical Procedures

Conservative surgery is performed in an attempt to keep all organs of the inner ear intact while controlling vertigo and preserving the patient's hearing and vestibular function.

Endolymphatic Sac Surgery

Endolymphatic sac surgery is the most conservative of the surgical procedures for Meniere's disease. It aims to reverse endolymphatic pressure while preserving hearing. It is an outpatient procedure that takes about 1 to 2 hours. Typically the recovery period is short and some people go back to work within several weeks (average 1-2 weeks).

Candidates for this surgery include patients who experience:

  • Early unilateral Meniere's disease
  • Intractable (not responsive to medical therapy), frequent, and severe vertigo
  • Fluctuations in hearing

The operation has several variations and is designed to decompress the endolymphatic sac from overlying bone and/or place a stent to aid in drainage of excess endolymphatic fluid. The restoration of normal pressure is thought to relieve vertigo symptoms. Although this operation has the lowest chance for major complications, it is also the least effective.

Symptom relief as described in the medical literature is highly variable and ranges from being very successful (up to 75% of patients) to being nothing more than a placebo effect. Up to 60% of patients report significant vertigo control at 2-5 years. Approximately 75% of the patients who have this operation do not feel the need to proceed with more aggressive surgical options. Surgical decompression has little or no affect on hearing and/or balance.

The major advantages of this surgical procedure include:

  • Low risk of hearing loss
  • Low risk of loss of vestibular function (balance)
  • Low incidence of complications

Though complications are infrequent, they may include:

  • Bleeding
  • Infection
  • Hearing loss (5%)
  • Persistent balance problems (50%)
  • No improvement in vertigo attacks (approximately 40%)
  • Facial nerve injury with resultant facial paralysis (0.1%)
  • Change or loss of sense of taste
  • Cerebrospinal fluid leak (rare)
  • Meningitis (rare)

Despite the controversy surrounding this procedure, responses to surveys of neurosurgeons and ear surgeons indicate that it is still the most commonly performed procedure for controlling vertigo attacks in Meniere's disease.

Some patients with bilateral Meniere's disease who suffer from intractable vertigo are also candidates for endolymphatic sac surgery since all inner ear organs remain intact and the risk of additional hearing loss is low. This surgical approach may also benefit some elderly patients with Meniere's who may be at high risk of falling due to other medical issues and cannot undergo other surgical procedures that may increase vestibular dysfunction.

Ablative Procedures

Ablative procedures involve destruction of inner ear organs and are reserved for patients with severe, intractable vertigo who do not respond to any medical treatment. Ablative procedures control vertigo in over 90% of cases, however, some cause deterioration of hearing and balance function in the affected ear. As a result, some of these procedures considered only for patients who have hearing loss in addition to severe vertigo.

Ablative procedures include:

  • Labyrinthectomy
  • Intratympanic gentamicin (chemical labyrinthectomy)
  • Vestibular nerve section
Labyrinthectomy

A labyrinthectomy is a surgical procedure that destroys the balance organ (labyrinth) of the affected inner ear in order to prevent vertigo attacks. This operation takes about 1-2 hours and has been considered the "gold standard" of procedures to control vertigo as it alleviates symptoms in 95% of patients. The major disadvantage of this procedure is that the patient is guaranteed to be deaf in the operated ear since labyrinthectomy virtually destroys the inner ear.

Candidates for this surgical option include:

  • Patients with unilateral Meniere's disease who suffer from:
    • intractable vertigo
    • severe-profound hearing loss
    • very poor word recognition
  • Elderly patients in good medical condition with limited hearing in the affected ear who may opt for this surgery because of its safety and simplicity

Before a labyrinthectomy can be performed, the patient must undergo testing to confirm the unilaterality of the Meniere's disease and prove that the second ear is healthy and unaffected since it will play a major role in central compensation of balance. If a labyrinthectomy is performed on a patient with bilateral Meniere's disease, it may cause:

  • Oscillopsia - a visual disturbance where objects in a person's visual field seem to swing, move back and forth (oscillate), jerk, or wiggle.
  • Permanent imbalance since there is no opportunity for an unaffected vestibular system (from the contralateral ear) to promote central compensation

Complications of labyrinthectomy are not common but may include:

  • Bleeding
  • Infection
  • Change or loss of sense of taste
  • Facial nerve injury (2%)
  • Cerebrospinal leakage (3%)
  • Meningitis

The hospital stay is usually 1-3 days with return to work in 4-8 weeks. After surgery, patients will usually experience severe vertigo for several days. Like with the other surgical procedures, the quicker one gets up and moves about, the faster the recovery begins.

Intratympanic Gentamicin

Intratympanic gentamicin was originally introduced as a treatment option for Meniere's disease in 1957 but fell out of favor due to the high incidence of sensorineural hearing loss which resulted from the chemical destruction of the labyrinth. Gentamicin is typically the drug used (may also be streptomycin) and is extremely toxic to the organs of the inner ear. Despite this significant side effect, one of the biggest advantages of intratympanic delivery was that the body is not exposed to systemic side effects of the medication, including destruction of the vestibular system and auditory organs of the contralateral ear.

Intratympanic gentamicin has recently made a comeback as an effective treatment option for Meniere's disease due to the new system of administration, namely titration of the drug where the dose is given in low-dose installments and adjusted for maximum effect. Thus the destruction of the labyrinth is gradual and can be discontinued at any time. The result of this new protocol for delivery of gentamicin is that it achieves excellent control of vertigo with considerably lower incidence of hearing loss. In addition, hearing loss can be monitored so that treatment can be suspended at the first sign of hearing loss.

Candidates for intratympanic gentamicin include patients with the following conditions:

  • Unilateral Meniere's disease
  • Willing to risk increased hearing loss
  • Severe, unremitting vertigo that has not responded to prior medical therapy

Initially, a tube is surgically placed through the tympanic membrane. For administration of the gentamicin, the patient lays down on their back on the treatment table with their head turned towards the good ear. The medication is injected through the tube and the patient remains lying down for 30 minutes during which time the medication is absorbed into the inner ear through the oval window membrane that separates the middle and inner ear. Any extra medication remaining in the ear canal is then aspirated. The ear must be kept dry for two weeks.

Follow up visits begin 3-4 weeks after the first injection. While most patients report varying degrees of relief from vertigo symptoms after one injection and do not need more, some patients may require repeated injections to achieve an acceptable reduction of symptoms. Patients are generally offered the injection 6-10 times before the treatment is considered a failure. All aspects of inner ear function, namely hearing (audiogram), balance, nystagmus, and motion intolerance must be monitored carefully and frequently at each follow-up appointment to detect any signs of complications. Gentamicin injections are discontinued at the first sign of:

  • Hearing loss
  • Control of vertigo
  • Reduced vestibular function (loss of balance)

Complications of intratympanic gentamicin include:

  • Bleeding
  • Infection
  • Eardrum perforation with need for later repair
  • Hearing loss (up to 30% of patients)
  • Worsening of word recognition (up to 30% of patients)
  • Change or loss of sense of taste
  • Persistent balance problems
  • Facial paralysis (least likely to happen with this procedure compared to other surgical procedures for Meniere's)

Intratympanic gentamicin is the least invasive procedure for intractable vertigo. Some surgeons consider it as a procedure to be explored after unsuccessful endolymphatic sac surgery but before other ablative surgery, while other surgeons report that patients who have had prior endolymphatic sac surgery may not respond as well to intratympanic gentamicin as those who have not undergone that procedure possibly due to changes in the membranes of the inner ear. There are also surgeons who recommend intratympanic steroids (described above), which is a nondestructive treatment, before offering intratympanic gentamicin that ultimately is guaranteed to destroy some or all of the labyrinth.

Due to the risk of significant hearing loss with intratympanic gentamicin, each patient needs to consider if they are willing to sacrifice hearing (which may or may not already be compromised) in exchange for relief of vertigo. If one is not willing to take that risk, they should consider other surgical options.

Outcomes for treatment with intratympanic gentamicin for Meniere's disease include:

  • Control of vertigo - 75-100%
  • Risk of (additional) hearing loss - 0-37%
  • Profound hearing loss - 3%
  • Recurrence of vertigo - up to 30%

A study published in Acta Otolaryngolica in June 2007 reported that 6 months after 57 patients received intratympanic gentamicin the following data was obtained:

  • Complete or substantial vertigo control - 80% of patients
  • Hearing worsened - 15% of patients
  • Word recognition scores worsened - 31% of patients

For approximately 49% of the patients, one injection was sufficient for vertigo control. For those needing multiple injections, there was a time interval of a minimum of 27 days between injections.

For more information about this study, please click on the following link: http://www.ncbi.nlm.nih.gov/sites/entrez?Db=PubMed&Cmd=ShowDetailView&TermToSearch=17503229&ordinalpos=11&itool=EntrezSystem2.PEntrez.Pubmed.PubmedResultsPanel.PubmedRVDocSum

A long term follow-up study completed in 2003 at Johns Hopkins University showed that of 34 patients who received intratympanic gentamicin, 90% experienced complete control of vertigo. Hearing deteriorated in 17% of patients. Twenty-nine percent of the patients experienced recurrent vertigo at 4-15 months after complete control was obtained. Readministration of the injection was effective for these patients with no increase of hearing loss.

For more information about the long-term results of intratympanic gentamicin delivery, please click on the following link: http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=ShowDetailView&TermToSearch=12792316&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.PubmedResultsPanel.PubmedRVDocSum

Although it was always considered important for the patient undergoing intratympanic gentamicin to have unilateral Meniere's with a healthy vestibular system of the contralateral ear to aid in central compensation, there is limited evidence that patients with bilateral Meniere's may also benefit. A small study completed in 1994 examined bilateral intratympanic gentamicin treatment for 14 patients with bilateral Meniere's disease. Results indicated that vertigo was eliminated in 11 patients and controlled in the remaining 3 patients. No patients experienced a significant change in hearing.

Vestibular Neurectomy

Vestibular nerve section (VNS) is the most efficient way of controlling vertigo attacks in Meniere's disease that are unremitting despite medical therapy. It is the most invasive of the surgical procedures available for Meniere's disease. The objective of VNS is the elimination of vertigo by cutting the vestibular portion of the 8th cranial nerve (vestibulochoclear nerve) while preserving hearing by keeping the cochlear portion of the nerve intact.

This procedure takes approximately 3-4 hours. The surgeon performs a craniotomy (part of the skull is removed) in order to gain access to the vestibular nerve and severs the fibers that lead to the brain. This destroys the balance mechanism in that ear (since signals are cut off from reaching the brain) but usually preserves hearing. The brain no longer receives conflicting messages from the affected vestibular system thus eliminating vertigo.

Recovery from VNS typically involves an overnight stay in the intensive care unit followed by a 3-7 day hospital stay. Patients often experience a severe attack of vertigo after surgery that gradually improves. The quicker the patient is up and walking, the faster the recovery. Recovery tends to be more rapid with younger patients. The return to work is usually within 4-8 weeks. Following surgery, it is important for the patient to enter an active vestibular rehabilitation program in order to promote central compensation and restore vestibular function as quickly as possible.

Patients who opt for this surgical procedure typically:

  • Suffer from unilateral Meniere's disease
  • Have severe vertigo which is refractory to previous treatments
  • Have serviceable hearing

Many young people opt for this surgical procedure despite its invasiveness and potential for complications since there is a high rate of hearing preservation and control of vertigo is virtually guaranteed. The percentage of patients with significant vertigo control at 2-5 years is 91-93%.

Many patients report that even years after surgery, they may still feel dizzy with a rapid head turn or if they step off a curb. If vertigo persists after VNR, the patient may benefit from treatment with intratympanic gentamicin.

Because of the important role played by the vestibular system in the unaffected ear in restoring balance, surgeons are very selective regarding this procedure for elderly patients who have a higher rate of medical conditions that may affect central compensation and restoration of balance. Like labyrinthectomy, VNS is contraindicated in bilateral vestibular disease since surgery under these conditions could result in oscillopsia and permanent imbalance.

While the greatest advantage of VNS is the high rate of success for controlling vertigo and preserving hearing, the primary disadvantage is that it is major surgery and is, therefore, associated with more operative risks than other procedures.

Although complications are not common, they may include:

  • Bleeding
  • Infection
  • Sensorineural hearing loss (10%)
  • Persistent vertigo (3-7%)
  • Facial nerve injury with resultant facial paralysis (0.1%)
  • Change or loss of sense of taste
  • Risk of cerebrospinal fluid leakage and meningitis are higher with this procedure than with others

Complication rates are lowest when the procedure is done by otologic surgeons or neurosurgeons that have substantial training and experience with this procedure. It is also important that the hospital staff that cares for the patient after surgery also have experience with patients undergoing VNS.

While some clinicians recommend VNS after failed endolymphatic sac surgery, others recommend this surgery after treatment with intratympanic gentamicin has failed. There are no professional guidelines regarding the point at which this surgical procedure should be chosen as the next treatment option.

A study published in Otology and Neurotology in February 2007 comparing hearing loss following treatment with vestibular nerve section or intratympanic gentamicin concluded that although vertigo control was excellent after each treatment, hearing loss was significantly greater following intratympanic gentamicin than with vestibular nerve section.

To read more about this study, please click on the following link: http://www.ncbi.nlm.nih.gov/sites/entrez?Db=PubMed&Cmd=ShowDetailView&TermToSearch=17255880&ordinalpos=17&itool=EntrezSystem2.PEntrez.Pubmed.PubmedResultsPanel.PubmedRVDocSum