Superior Canal Dehiscence
Vestibular Neuronitis And Labyrinthitis
Bilateral Vestibular Hypofunction
Persistent Postural-Perceptual Dizziness
Mal De Debarquement
Benign Paroxysmal Positional Vertigo (BPPV) is the most frequent cause of dizziness. It is more commonly described as having “displaced crystals in the ear”.
The inner ear has two functions: hearing and balance. The cochlea is responsible for hearing. The balance function is conveyed by three semicircular canals as well as a utricle and saccule. The canals sense rotational movements and the utricle and saccule are responsible for vertical and horizontal movements.
The utricle and saccule contain a membrane that holds crystals that we call otoliths. The movement of these crystals over the membrane allows us to sense the movement of the body. When these crystals fall off the membrane, gravity pulls them into the semicircular canals (watch animation video). The cause of displacement of the crystals is often times indeterminate. We know that head trauma - even a minor blow to the head - is a risk factor. An infection in the ear also predisposes this to happen (see vestibular neuronitis section below). It is most prevalent in elderly people and especially postmenopausal women. Although we don’t have hard evidence, vitamin D deficiency may be a predisposing factor. The otoliths are, after all, calcium carbonate crystals.
The prevalence of BPPV is also increased in patients with other problems of the inner ear, including Meniere’s disease and Vestibular Migraine.
Typically, when the crystals fall into the posterior semicircular canal, every time the patient lies down with the affected ear down, the crystals move the fluids of the inner ear activating the sensor of the semicircular canal inappropriately. This is perceived as vertigo or spinning by the patient and lasts less than a minute until the crystals settle down and stop moving.
In active people the BPPV will resolve in a matter of a couple of weeks. We can accelerate the resolution by giving the patient habituation exercises called Brandt-Daroff exercises, which will consist of shaking the crystals within the fluids by alternating body positions and ultimately dissolving them. We can also do a repositioning maneuver called Epley move the crystals back into the utricle.
Find out more about BPPV.
French physician Prosper Meniere described the disease bearing his name in the 19th century after seeing several patients who presented with episodic vertigo attacks that would come out of nowhere. He also noticed that a lot of these patients develop ringing and hearing loss in one ear. The typical symptoms of Meniere’s disease are episodic attacks of vertigo (spinning), lasting between 20 minutes and 12 hours, and are associated with tinnitus/ringing in the ear and fullness in the affected ear. When the vertigo resolves, the tinnitus and the fullness also disappear. If we get a hearing test close to the spell there is a hearing loss in the low pitch sounds. The patient usually comes back to normal following the episode. The pathophysiology of Meniere’s disease consists of a decline in hearing. In some people, Meniere’s disease may become bilateral. This usually happens within the first five years of presentation in the first ear. The longer the patient suffers from the disease, the less likely he or she will develop it in the contralateral ear.
Although Prosper Meniere did note it in his own patients, it is now more readily acknowledged that Meniere’s disease patients have a higher lifetime prevalence of migraines (up to 50 percent in all patients and around 75 percent in women).
We do not know what causes Meniere’s disease. We do know that the symptoms are due to increased pressure in the fluids of the inner ear (the endolymph). Treatment starts with low salt diet to less than 1500 mg a day and a diuretic called Dyazide®. If the episodes are very frequent we can inject steroid through the ear drum. If there is not substantial hearing loss, a surgical intervention consisting of an endolymphatic sac decompression may be recommended to relieve the pressure within the inner ear. Should hearing decrease, one of the more aggressive treatment options is to inject gentamicin through the ear drum. Gentamicin works by decreasing the sense of balance within the ear and alleviates the perception of vertigo and spinning. The final surgical option entails performing a labyrinthectomy which consists of drilling out the inner ear. In people who have bilateral Meniere’s disease and have lost their hearing bilaterally, cochlear implants are an option.
General tips for Eating Well with the Meniere's Disease.
Find out more about the Meniere’s Disease.
Migraine is a very obscure disease. To this day we do not know the actual inciting event behind the classical terrible spells of headaches that debilitate the individual for several hours, and even days at times.
Obviously, migraine gave way to a lot of mystical explanations over the years. It has been reported in Greek and Antique treatise. It has been recognized as the “cause” of Hildegaarde’s mystic visions (Hildegaarde is a german nun who was canonized in the thirteenth century). The detailed depiction of her visions corresponds to visual auras followed by splitting headaches. In the nineteenth century, it was theorized to be a seizure, but this was ruled out with the advent of electroencephalograms and more evidenced-based science. Migraine is often considered as the body’s response to shut itself out from the surrounding environments. It is no wonder stress, allergies and inclement weather are common triggers.
In children, it manifests very unusually with what we call cyclical vomiting without any abdominal cause. These patients are most typically disturbed by bright lights and loud sounds and have motion sickness. Most recently, we began to recognize a subgroup of patients who experience what is now commonly referred to as a vestibular migraine. This is a migraine that affects the vestibular system and causes episodes of vertigo or dizziness lasting from 5 min to 72 hours. The patients must have an associated headache (before, during or after the episode) or a headache history or exhibit migraine equivalents such as photosensitivity, motion sickness, visual auras/ophthalmic migraines. In addition, these patients often experience what we call visual vertigo. Common complaints consist of dizziness in certain busy, crowded environments or when they are driving over a bridge where the depth of perception is usually difficult to adjust. 20 percent of vestibular migraine patients may ultimately develop a form of generalized anxiety disorder, that we call Persistent Postural Perceptual Vertigo, if left untreated and undiagnosed.
Treatment starts with identifying triggers such as allergies and certain food items (see complete nutrition guide for migraine below). If the spells are frequent enough (more than once a week or at least 4 a month), anti-migraine medication may be indicated.
- Nortriptyline(Pamelor®), a tricyclic antidepressant, is a great migraine preventive. It is started at a low dose of 20 mg and we can escalate it as tolerated up to 75 mg. It is not associated with major side effects at this dose. However, certain patients develop an non-dose dependent response with vivid dreams and insomnia, which can be a reason to stop. Other side effects may include dry mouth and constipation. The only contraindication is an arrhythmia and usually an EKG or a recent cardiac work-up are advised before starting it. In addition, it can cause weight gain and this may be a relative contraindication in an overweight person. Amitriptyline (Elavil®)is a drug of the same family that is often used for the same indication.
- Topiramate (Topamax®) is a seizure preventive medication and it can be used to treat migraines. The dose is carefully carefully from 25 mg a day to 50 mg twice a day. Patients tend to tolerate it less but it is a very effective medication. It can also assist with weight loss. It is relatively contraindicated in subjects with a history of kidney stones. The major side effect is what patients describe as “I feel like I am in a fog”. They feel like they have memory problems, attention issues and are not able to concentrate on things. It can be stopped it without tapering it down and the symptoms are always reversible.
- Venlafaxine (Effexor®) is another antidepressant but it also works for migraine, usually at the dose of 37.5 mg once in the morning.
Finally, certain blood pressure medications can be used for migraines, such as beta-blockers and calcium channel inhibitors and the two representatives of these categories of medications: Propranolol (Inderal®) and Verapamil (Calan®). In pregnant women, or if those medications don’t work we can use magnesium supplements, usually Magnesium Gluconate 500 mg tablets 2-4 tablets twice a day. If all medical options fail, the patient may be a candidate for Botox injections according to the PREEMPT protocol. These injections are done every 12 weeks and after the third series of injection, studies show a decrease of the frequency of headaches of 70 percent on average. Of course, treating the headaches will also eventually clear the vertigo episodes.
General tips in tracking Nutrition for Migraines.
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Superior canal dehiscence is a recently recognized pathology described in 1998. The superior semicircular canal is a part of the inner ear balance system. Typically, there is bone covering it and separating from the overlying brain. In certain patients, that bone layer is very thin or absent and the superior canal is directly in contact with the meninges, lining of the brain. These patients manifest symptoms of vertigo induced by sound or by coughing, sneezing, squatting. They also present with imbalance and autophony, which is a sensation of echoing of one’s own voice in the affected ear. They can at the same time complain of pulsatile tinnitus with a pulsing sound in their ear. Most of the time we do nothing about it if the symptoms are not affecting the patient’s quality of life tremendously. If the symptoms are extremely debilitating there is several surgical options which can be more or less aggressive.
The most conservative option would be to place a tube in the ear drum, which diverts the sound energy and diminishes the sound-induced symptoms.
Another option would be opening the middle ear and identifying the round window, which is one of two “windows” to the inner ear, and blocking it with a piece of cartilage.
Classically, however, the dehiscence should be repaired directly, through a craniotomy. The dehiscence is identified and a piece of bone is used to plug it. In certain patient we can avoid a craniotomy and open the mastoid cavity behind the ear and slip a piece of cartilage or perichondrium (cartilage cover) over the dehiscence and under the meninges. These surgical approaches work both on the auditory and vestibular symptoms. There is a risk of transient postoperative vertigo as well as a hearing loss of variable severity in these cases.
Vestibular schwannoma, also called an acoustic neuroma is a benign slow-growing tumor that develops from the balance nerve supplying the inner ear. The name schwannoma comes from the fact that the tumor arises from the proliferation of Schwann cells which form the sheath of the balance nerve. As the tumor grows, the balance function progressively worsens. Patients usually notice a unilateral hearing loss and tinnitus. There is rarely an acute dizziness because the growth is slow. Imbalance is also more slowly developing because the patient compensates using the contralateral vestibular function. In certain cases, the growth of the tumor can impinge on the trigeminal nerve (nerve that conveys sensation to the face) causing facial numbness. More rarely it can cause facial weakness by compressing the neighboring facial nerve. Since the facial nerve is located in the same bony canal as the balance nerve, a tumor in this location with facial weakness should raise the suspicion of a facial schwannoma. When the tumor grows to the point where it starts compressing the cerebellum and the brainstem, symptoms become more severe and potentially life-threatening.
The incidence of vestibular schwannoma is 1 in 100,000 subjects per year. It is usually a unilateral, non-familial pathology. In the setting of a genetic disease called neurofibromatosis, patients can develop bilateral acoustic neuromas. Most frequently, acoustic neuromas are diagnosed with an MRI ordered in the setting of an asymmetric hearing loss. Less than 10 percent of cases of sudden sensorineural hearing are found to have a vestibular schwannoma. The sudden decrease is hearing is due to a rapid increase in size of the tumor because of a hemorrhage within the tumor. Once a vestibular schwannoma is diagnosed there are three options to discuss with the patient. If there are no life threatening symptoms, we usually observe and repeat the MRI in 8-12 months to monitor whether or not the tumor has grown. Once the growth of the tumor is objectively put in evidence, treatment options may include either radiation (gamma knife, cyberknife) which will stop the growth of the tumor, or surgery.
Radiation stabilizes the tumor. There is a lower risk of facial nerve weakness and generally the hearing may be potentially preserved (depending on the size of the tumor). However, there is a progressive decrease in hearing on longer term results, especially depending on the amount of radiation the cochlear receives during the treatment. This option is generally suggested when the tumor is less than 2.5 cm in size and in elderly patients or those with contraindication to surgery. Surgical approaches depend on the degree of hearing loss and the size and location of the tumor.
Find out more about vestibular schwannoma.
These are disorders arising from an inflammation of the inner ear or the nerves of hearing and balance. Vestibular neuritis is generally believed from a reactivation of varicella zoster virus (VZV). VZV is a virus of the herpes family and is implicated in chicken pox one of the childhood common viral illnesses. The virus lies dormant after the infection and when it gets reactivated it can cause shingles or sometimes vestibular neuronitis if it reactivates in the balance nerve. The patient present with severe spinning dizziness with nausea and vomiting. The spinning is exacerbated with every motion of the head. It is self-remitting within a few days. Treatment is symptomatic. We use antinausea medication as well as vertigo suppressant. This is probably the only indication to use meclizine (Antivert, Bonine) for a short, limited period of time.
Labyrinthitis is an inflammation within the inner ear and it usually manifests with dizziness and hearing loss. We can see it in the context of a chronic middle ear effusion and in that case it is not usually an infection but only a mere inflammation. Occasionally, an acute otitis media can cause translocation of bacteria from the middle ear to the inner ear and causes the much more debilitating suppurative labyrinthitis.
Find out more about vestibular neuronitis and labyrinthitis.
Patients with bilateral decrease in function of their balance system are usually very debilitated. They present with chronic imbalance especially in the dark or an uneven surface. It can in extreme cases decrease the patient’s ability to see clearly during head movements. This latter symptom is known as oscillopsia. The most frequent causes are ototoxicity from chemotherapy drugs for instance but also antibiotics, meningitis, autoimmune disorders, polyneuropathy, neurofibromatosis with bilateral vestibular schwannoma. In most cases it is idiopathic. Unfortunately, there is no treatment that reverses the vestibular loss. The best course of treatment is vestibular rehabilitation. It consists of gaze stabilization exercises as well as exercises that increase postural stability and allow the patient to use the alternate systems of vision and proprioception to adjust for the missing vestibular information.
Future treatment will consist of developing a prosthesis that replaces the missing vestibular function, much like the cochlear implants replace the hearing function. Several labs are currently working on developing vestibular implants. The majority of the work with this prosthesis has been so far performed in bilaterally vestibular-deficient chinchillas and monkeys. The basic design is that sensors will detect and measure the directions of rotation and then electrically stimulate the appropriate ampullary nerves.
Clinical application in humans is still not for the near future.
Find out more about bilateral vestibular hypofunction.
It is formerly known as Phobic Postural Vertigo and Chronic subjective dizziness. Symptoms include a persistent sensation of rocking or swaying unsteadiness and/or dizziness without vertigo lasting three months or more. Symptoms are present at least 15 days out of the month. Worsening factors are upright posture (standing or sitting upright), head or body motion, exposure to complex or motion-rich environments. Typically, PPPD starts shortly after an event that causes acute vertigo, unsteadiness, dizziness or imbalance such as BPPV, vestibular neuronitis, Meniere’s disease, vestibular migraine, panic attacks with dizziness, mild traumatic brain injury and dysautonomia. Individuals with anxious personalities and especially those who display high levels of anxiety following an acute vestibular event, are the most at risk for developing PPPD. High anxiety worsens postural stability and reactivity to motion stimuli during an acute vestibular event. Recovery is slowed and prevents the patient from developing adaptive strategies. 60 percent of patients have clinically significant anxiety, 45 percent have clinically significant depression but 25 percent have neither. Treatment involves SSRI, vestibular rehabilitation as well as counseling. Counseling is most successful when it is started early after the triggering event.
Find out more about Persistent Postural-Perceptual Dizziness.
It literally means sickness of disembarkment. It refers to an illusion of movement felt as an aftereffect of travel on water most frequently. Most individuals will recover following exposure to motion within a few days. It becomes pathological if it persists more than a month. Most patients note a resolution of their symptoms within 12 months. Middle-aged women are most at risk, following exposure to an unfamiliar movement and removal of the stimulus. The pathophysiological process seems to arise from the brain rather than the inner ear. Functional MRI studies suggest that the brain is able to adapt to an unfamiliar movement but is unable to readapt once the movement has stopped. Most commonly, the patients describe their symptoms as rocking, swaying and disequilibrium and rarely a spinning vertigo. The symptoms are worsened when the subject is in an enclosed space or when they are motionless. They feel better when they are moving or driving. Diagnosis is made after taking an appropriate history and after ruling out other disorders that can cause dizziness. There is no single effective treatment for Mal de Débarquement Syndrome. Short-term use of benzodiazepines and may alleviate the symptoms. However, prolonged use may cause delay in the necessary compensation to recover. Vestibular rehabilitation is controversial. Early exposure to motion may exacerbate symptoms. After a variable wait time for spontaneous resolution it can be suggested. The rehabilitation will focus on readjusting the maladapted vestibulo-ocular reflex.
Find out more about Mal de debarquement.
To view any of the publications, you may access the Vestibular Disorders Association website.