Dizziness and Vertigo
Hearing and balance involve proper functioning of 3 areas:
The outer ear which includes the ear canal and ear drum outer layer (tympanic membrane)
The middle ear, which includes the inner ear drum (tympanic membrane), and the bones of hearing which are the malleus, the incus, and the stapes.
The Inner ear which includes the organ of hearing (cochlea), and the vestibule, which includes the semicircular canals.
Balance is primarily controlled by the inner ear, more specifically, the vestibule, which contains the semicircular canals. There are three semicircular canals
Posterior canal
Horizontal canal
Superior canal
These canals are bony on the outside and fluid filled on the inside. The canals work with your vision and pressure preceptors to help you maintain a steady feeling with position changes and sound. When any part of this system has a defect, it can cause changes in your balance and equilibrium.
Superior Semicircular Canal Dehiscence (SSCCD)
Superior semicircular canal dehiscence is a rare defect where an area of bone covering the superior canal is no longer present. This is thought to occur from birth, where the bone improperly forms thinner than average. Over time the thin bone is worn down slowly and can be broken down by minor traumas to the head or chronic ear infections.
Many of the symptoms of semicircular canal dehiscence can be elicited from loud sounds or pressure changes such as activity, straining, coughing, blowing nose, or altitude changes. Such symptoms include:
Dizziness
Vertigo
Uncontrolled eye movements or twitching
Visual distortion
Sensitivity to sound (hyperacusis)
Other symptoms not necessarily related to loud sounds or pressure changes include:
Ringing in the ear (tinnitus)
Hearing loss, however patients often feel they can hear sounds in the inner body more clearly, such as sounds coming from their joints or their eyes blinking.
Autophony, meaning the sound of the patients own voice is very loud in the affected ear.
Fullness in the affected ear.
Superior semicircular canal dehiscence can be suspected based on symptoms, a hearing test, and a special VEMP test. If the results raise suspicion, a special CT of the head can be obtained to confirm the diagnosis. Surgical treatment is based solely on how bothersome the symptoms are to the patient. If the symptoms are not extremely bothersome, they can be managed by using special musician earplugs and avoidance of symptom triggers such as loud sound and pressure changes. However, if the symptoms are very bothersome and are interfering with daily life, surgical repair can be considered to replace the missing temporal bone of the roof of the superior semicircular canal. Generally, the outcome is favorable as about 90% of patients report relief of their symptoms.
Benign Paroxysmal Positional Vertigo (BPPV)
Causes of Benign Paroxysmal Positional Vertigo (BPPV) are varied, but can be associated with genetics, head trauma and inflammation of the ear. Typically its onset is spontaneous without identifiable cause. BPPV develops when calcium carbonate crystals, which are known as otoconia, shift into and become trapped within the semicircular canals (one of the vestibular organs of the inner ear that controls balance). Movements that can trigger an episode of BPPV include rolling over or sitting up in bed, bending the head forward to look down, or tipping the head backward. In most people, only a single ear is affected by BPPV, although both ears may be involved on occasion.
After accurate diagnosis with the Dix Hallpike test, it is easily treated with particle re-positioning therapy (i.e. Epley Maneuver) that is tailored to the site of the disruption. These exercises are performed for 1-2 weeks and can be escalated with the use of a therapist for persistent symptoms. Sometimes BPPV resolves after only one session, in others it can recur over time.
Vestibular Neuritis/Labyrinthitis
Vestibular neuritis is an inflammation of the nerve of balance. Viruses are thought to be the cause of this inflammation, as vestibular neuritis often occurs after an upper respiratory infection. Typically, patients experience a sudden onset of severe vertigo, nausea, and vomiting with episodes lasting several days. Similarly, labyrinthitis is an inflammation of the entire inner ear (labyrinthine), including the organ of hearing (cochlea). Therefore patients generally will experience significant symptoms of hearing loss in addition to dizziness, imbalance, vertigo, nausea, and vomiting. This gradually will improve, however it may take several weeks. Medications such as steroids or antivirals can be used to reduce the inflammation and infection. Generally after improvement, symptoms will resolve. However, some patients are left with residual weakness in their balance system or permanent reduction in hearing. They may require treatment with a vestibular therapist or hearing amplification.
Anti nausea/vertigo medications, which are sometimes used acutely to treat symptoms during episodes, can further affect your ability to compensate for vestibular weaknesses if used long term. For this reason the Texas Ear Clinic rarely uses these medications.
Meniere’s Disease (Endolymphatic Hydrops)
Meniere’s disease is a disorder of the inner ear, which causes multiple symptoms, typically presenting as episodes:
Dizziness/spinning sensations
Fluctuations in hearing (which may ultimately end in a permanent hearing loss)
Fullness sensation
Roaring tinnitus
Typically this only occurs in one ear, however a small number of people experience Meniere’s bilaterally. To get a better idea of the underlying mechanism of Meniere’s it is important to understand some of the anatomy of the inner ear. The inner ear consists of the organ of hearing (cochlea), and the balance system (semicircular canals and vestibule). Together, the cochlea, vestibule, and the semicircular canals make up the labyrinth. This is made of a hard like bone on the outside and fluid filled on the inside. The fluid is called endolymph. This endolymph circulates throughout the inner ear and helps to carry out electrical charges sending signals to the brain. The root cause of Meniere’s disease is unknown, though the symptoms are thought to occur because of abnormal fluctuations of sodium and potassium ions or an increase in the inner fluid, termed “endolymphatic hydrops.”
Typically a hearing test will be preformed to monitor fluctuations in the hearing, document the degree of hearing loss, and to assess for a low frequency hearing loss. A complete vestibular battery of tests will also be performed with a specialized test called an electrocochleogram (ECoG) to further assist in a diagnosis of Meniere’s disease. Typically, if this test is positive, enodlymphatic hydrops is likely. However, a negative test does not always rule out Meniere’s disease. Once a diagnosis is made, treatment is aimed at decreasing the amount of fluid or pressure of the endolymphatic fluid:
Low salt diet.
Avoiding caffeine, nicotine, allergens and high stress levels.
Diuretics such as hydrochlorothiazide or furosemide.
Betahistine, a compounded drug, has shown to help with episodes of vertigo, and at times with hearing fluctuations and aural fullness. We have found this to be very beneficial to many of our patients.
In the case of a sudden drop in hearing or a sudden sensorineural hearing loss, intratympanic steroid treatments are recommended as soon as possible.
If symptoms still persist despite the previous mentioned treatments and lifestyle changes, surgical intervention may be considered. These are typically reserved as a last resort as some may cause a complete loss of hearing or balance function on the affected side. Options include:
Intratympanic Gentamicin: By placing gentamicin directly into the middle ear, it destroys some or all of the balance cells, making then incapable of causing dizziness. A risk for more hearing loss or worsening of symptoms exists with this method.
Endolymphatic sac decompression: Surgery consists of directly opening or decompressing the sac that holds the endolymphatic fluid. This works to relieve pressure in the inner ear and typically does not affect hearing.
Labyrinthectomy: With this surgery, the affected inner ear is completely eliminated. This in turn removes all function of the inner ear including hearing and balance on the affected side. The reasoning behind this is that one functioning balance system works better than one functioning and one malfunctioning balance system. However, it takes time to adjust to a one sided functioning balance system and usually requires vestibular therapy to aid in compensation.
Vestibular neurectomy (nerve section): With this surgery the balance nerve (vestibular nerve) leading to the brain is cut. This surgery is performed to remove the signal from the faulty balance system to the brain to ensure the faulty information does not reach the brain to tell the body it is dizzy. Typically the hearing is preserved with this surgery, however just as with a labyrinthectomy, it requires a recovery period with the use of vestibular therapy to fully compensate for the loss of balance function on one side.
Migraine Associated Dizziness (Vestibular Migraine)
Vestibular migraines are a phenomenon in which a migraine is expressed as dizziness rather than a headache. In the United States, migraines are extremely common with incidence seen in the female population 3 times more than the male population. Out of all migraine sufferers, about one third of people who have migraines experience their migraines as episodic vertigo. There have been many theories as to why this occurs, however no definite cause has been identified. Migraine associated dizziness can mimic other forms of dizziness such as Benign Paroxysmal Positional Vertigo (BPPV), vestibular neuritis, and Meniere’s disease. However, with migraine-associated dizziness hearing is not affected.
Vestibular migraines can last anywhere from 2-24 hours and typically become worse with visual motion, bright lights, peripheral vision changes such as walking down isles in a super market, driving a car, or loud sounds. Commonly, symptom relief is experienced after closing the eyes or lying in a dark and quiet room. Many patients with vestibular migraines report either a personal or family history of migraines currently or in the past. Female gender and history of motion sickness also increases the suspicion for vestibular migraines.
Treatment of vestibular migraines is typically the same as those who experience migraines in headache form. This includes keeping a food diary and avoiding certain foods that seem to cause symptoms of dizziness. Medication is also typically the same for those experiencing migraine headaches. At the Texas Ear Clinic we have found nortriptyline and Topamax to be very effective for patients who experience multiple episodes a month. medication.
Perilymph or Inner Ear Fistula
The inner ear, or bony labyrinth, contains the organ of hearing (cochlea) and the organ of balance (vestibule). These structures have hard temporal bone on the outside, and are fluid filled on the inside. There are two fluids within these organs.
Perilymph fluid
Endolymph fluid
An area connected to the cochlea called the round window membrane separates the middle ear from the inner ear. It also works to keep the fluids inside the organ of hearing and organ of balance. A disturbance to this membrane can cause the fluid to leak from the inner ear into the middle ear. This could disrupt the cochlea’s ability to transmit sound waves, resulting in a hearing loss, or could disturb the vestibule from maintaining complete balance function, causing the sensation of dizziness and imbalance. A perilymph fistula is a leak of the round window membrane. This can be caused by mild trauma such as straining/heavy lifting or an event such as barometric trauma or physical trauma to the head. There are other, less documented fistulas that can form in the inner ear as well. Any kind of trauma can cause micro tears in the inner ear membranes, leading to fistulas between inner ear organs.
Diagnosis is generally made by taking into account history, symptoms, and physical exam findings including a positive fistula test. If a form of trauma, discussed earlier, occurred just before symptoms started, this increases suspicion of perilymph fistula. If a perilymph fistula is suspected, treatment requires middle ear exploration and surgical intervention to repair the leakage from the defective round window membrane. Surgical repair will likely improve vertigo symptoms, however this does not always repair hearing loss.