Common Causes of Dizziness
Benign Paroxysmal Positional Vertigo (BPPV)
Benign paroxysmal positional vertigo (BPPV) is a disorder that causes vertigo, a spinning sensation, which usually lasts less than 30 seconds. Some patients also describe a vague type of balance problem (disequilibrium) between episodes. It is caused when otoconia fall free from the utricle and land in one of the semicircular canals. This changes the way the fluid in the semicircular canal moves and over-stimulates the sensory cells. Symptoms of BPPV are almost always related to a change in head position such as getting out of bed, rolling over in bed, or turning the head quickly. The vertigo typically begins about 1-2 seconds after the head movement. Some people feel dizzy and unsteady when they tip their heads back to look up. BPPV is the most common cause of dizziness and with an annual incidence of 10-50 cases per 100,000 people. Luckily, BPPV is also the most easily treated cause of dizziness. Treatment for BPPV is very effective and often is completed in a single visit to either the audiologist or a physical therapist. The goal of the treatment is to move the loose otoconia out of the semicircular canal and back into the utricle.
Meniere’s disease, also known as endolymphatic hydrops, is a disorder of the inner ear. Although the cause of Meniere’s disease is unknown, it is believed to result from an abnormality in the way the fluid of the inner ear is regulated. In most cases only one ear is involved, but both ears may be affected in about 15% of patients. Meniere’s disease typically begins between 20 and 50 years of age and affects men and women equally. The symptoms may be only a minor nuisance, or can become disabling, especially if the attacks of vertigo are severe, frequent, or long lasting.
There are four “hallmark” symptoms of Meniere’s disease. Many people exhibit all four symptoms during active flare-up of their Meniere’s disease; however, this is not the case for everyone.
- Episodic vertigo: Patient’s suffer from attacks of vertigo (spinning sensation) accompanied by disequilibrium (an off-balanced sensation), nausea, and sometimes vomiting. The vertigo may last 20 minutes to two hours or even longer. During attacks, patients may become very disabled, and sleepiness may follow. An off-balanced sensation may last for several days.
- Tinnitus: Patient’s may perceive a roaring, buzzing, machine-like, or ringing sound in the affected ear. It may be episodic and coincide with an attack of vertigo or it may be constant. Usually the tinnitus gets worse or will appear just before the onset of the vertigo.
- Hearing loss: A low frequency fluctuating hearing loss is typical in the early stages of Meniere’s. Over time, however, the hearing loss typically progresses and becomes permanent. Sounds may also become distorted in the affected ear.
- Aural fullness: Typically, prior to an onset of vertigo, the patient may experience a plugged or “full” sensation in the affected ear.
Labyrinthitis & Vestibular Neuritis
Labyrinthitis and vestibular neuritis are disorders resulting from an infection that inflames the inner ear or the vestibulo-cochlear nerve (the eighth cranial nerve), which connects the inner ear to the brain. Vertigo, dizziness, and difficulties with balance or hearing may result.
Infections of the inner ear are usually viral, although less commonly the cause may be bacterial. Although the symptoms of bacterial and viral infections may be similar, the treatments are very different so proper diagnosis by a physician is essential. Such inner ear infections are not the same as middle ear infections, which are the type of bacterial infections common in childhood affecting the area around the eardrum.
Neuritis (inflammation of the nerve) affects the vestibular branch of the vestibulo-cochlear nerve, resulting in dizziness or vertigo but no change in hearing. Labyrinthitis (inflammation of the labyrinth) occurs when an infection affects both branches of the nerve, resulting in hearing changes as well as dizziness or vertigo.
The onset of these disorders is usually very sudden, with severe dizziness developing abruptly during routine daily activities. In other cases, the symptoms are present upon awakening in the morning. Typically, the severe dizziness only lasts about 24 hours. However, mild dizziness may last for several weeks before clearing up completely. For some people, the dizziness may persist beyond several weeks.
Acoustic Neuroma/Vestibular Schwannoma
An acoustic neuroma is a benign tumor of the insulating cells (Schwann cells) of the eighth cranial (vestibulo-cochlear) nerve. The tumor develops on the vestibular portion of the eighth cranial nerve as it exits the brainstem at the cerebellopontine angle (CPA). Therefore, the main initial symptoms of an acoustic neuroma are usually related to impaired balance; however, symptoms such as tinnitus and unilateral hearing loss may also occur. Acoustic neuromas are also sometimes called “vestibular schwannomas” because they are made up of an abnormal growth of Schwann cells on the vestibular nerve. Acoustic neuromas are rare with only about 2,000 cases diagnosed in the United States each year.
Ototoxicity refers to the damage caused to the inner ear (labyrinth) from the use of various medications. These medications can damage the inner ear’s balance system, hearing system, or both. Symptoms of ototoxicity vary considerably from drug to drug and person to person. They range from mild imbalance to total incapacitation, and from tinnitus to total hearing loss. Once ototoxicity occurs, the damage is usually irreversible. The key to management of ototoxicity is both patient and physician awareness and prevention of the potential side effects of these drugs. If a patient notices a loss of hearing or a sense of imbalance, these symptoms should be reported to the physician immediately. If possible, the drug should be discontinued; however, many ototoxic medications are only used for battling otherwise life-threatening illnesses (i.e. cancer or severe infection) so discontinuation may not always be feasible.
Superior Canal Dehiscence Syndrome
Superior canal dehiscence syndrome (SCD) results from an opening (dehiscence) in the bone overlying the superior semicircular canal within the inner ear. With this dehiscence, the fluid in the membranous superior canal can be abnormally displaced by sound and pressure stimuli.
Vestibular and/or auditory signs and symptoms can occur in SCD. Vertigo and oscillopsia (the apparent motion of objects that are known to be stationary) can be evoked by loud noises and/or by maneuvers that change middle-ear or intracranial pressure (such as coughing, sneezing, or straining). Persons with SCD may experience a feeling of constant disequilibrium and imbalance, and may perceive that objects are moving in time with their pulse (pulsatile oscillopsia). Auditory symptoms of SCD may include autophony (increased resonance of one’s own voice), hypersensitivity to sounds, and an apparent conductive hearing loss revealed on audiometry.
Perilymphatic fluid surrounds the membranous structures (utricle, saccule, semicircular canals, and cochlea) of the inner ear. A perilymphatic fistula occurs when there is leakage of the perilymphatic fluid from a hole between the inner ear compartment and the middle ear or mastoid. This hole can result from surgery, trauma, infection, developmental (before birth) abnormality, or a sudden change in pressure. In rare situations, it can occur without any apparent cause.
The symptoms of a perilymphatic fistula may include dizziness, vertigo, imbalance, nausea, and vomiting. Usually however, patients report an unsteadiness which increases with activity and which is relieved by rest. Some people experience ringing or fullness in the ears, and many notice a hearing loss. Some people with fistulas find that their symptoms get worse with coughing, sneezing, or blowing their noses, as well as with exertion and activity. The diagnosis of a perilymphatic fistula can only be confirmed at surgery when the hole is actually seen. Although most perilymphatic fistulas will heal spontaneously with rest, in some situations, surgery is performed to patch the hole.
Otosclerosis is the abnormal growth of a bone in the middle ear. This bone prevents structures within the ear from working properly and causes hearing loss. For some people with otosclerosis, the hearing loss may become severe. The cause of otosclerosis is not fully understood, although research has shown that otosclerosis tends to run in families and may be hereditary. Research shows that white, middle-aged women are most at risk and some research shows a relationship between otosclerosis and the hormonal changes associated with pregnancy.
Hearing loss is the most frequent symptom of otosclerosis. The loss may appear very gradually. In addition to hearing loss, some people with otosclerosis may experience dizziness, balance problems, or tinnitus. In many cases a surgical procedure called a stapedectomy is an option for treatment of otosclerosis.
There are many other possible causes of dizziness that are not related to the vestibular system. Some other causes include: vertebral basilar insufficiency, vestibular migraines, circulatory problems, cervical/spinal problems, multiple sclerosis, and others. You should speak with your primary care physician or audiologist if you have dizziness so they can help direct you to the proper testing and medical resources.
Treatments for Dizziness/Imbalance
Depending on the cause of dizziness, there may be general or very specific treatment options.
Many people suffering from dizziness, vertigo, or imbalance benefit from physical therapy that is designed to strengthen and retrain the vestibular system. Vestibular therapy is effective in improving the functional deficits and subjective symptoms resulting from most vestibular problems. By improving vestibular function, vestibular rehabilitation aims to improve balance, minimize falls, decrease subjective sensations of dizziness, improve stability while walking, and reduce overdependence on visual or other sensory inputs.
For Meniere’s disease there are conservative and aggressive treatment options. Treatment will depend on the severity of symptoms and the recommendation of your physician.
- Diet & Life Style: A low salt diet is very helpful to reduce the attacks of vertigo. In fact, a meal high in salt may induce an attack. Avoid caffeine, smoking and alcohol. Regular sleep and remaining physically active, while avoiding stress and excessive fatigue may decrease the frequency of attacks and tinnitus.
- Medications: A diuretic (water pill) combined with a low salt diet, is the primary treatment for Meniere disease. Anti-vertigo medications may provide temporary relief during the attacks of vertigo. Anti-nausea medication is sometimes also prescribed. Both anti-vertigo and anti-nausea medications may cause drowsiness so caution must be used when taking these medications.
- Surgery: If vertigo attacks are not controlled medically and are disabling, surgery may be an option.
Patients diagnosed with an acoustic neuroma may also be treated conservatively or aggressively, depending on the severity of symptoms. One of the most common approaches when symptoms are mild is to simply monitor the growth of the neuroma with routine testing. If symptoms are more debilitating, more aggressive treatment options may include surgery.
For many patients with superior canal dehiscence, avoidance of provocative stimuli such as loud noises may be sufficient treatment. For patients who are debilitated by their symptoms, surgical plugging of the hole in the boney area above the superior canal can be very beneficial in alleviating or substantially reducing symptoms.
BPPV is treated with a very simple procedure. The procedure is called canalith repositioning or the Eply maneuver. During the Eply maneuver your doctor, audiologist, or physical therapist maneuvers the position of your head with the goal of moving the loose otoconia in your semi-circular canal to a place within your ear where they won’t cause dizziness and will ultimately be reabsorbed into your body’s fluids. The success rate of this procedure can be as high as 90 percent. You may need to have the procedure repeated. You may also be given home exercises that can help relieve your BPPV.
To combat vertigo associated with a vestibular migraine, your doctor will likely try to help you determine and avoid the triggers for your attacks. They may suggest that you avoid certain foods, reduce stress in your life, develop a regular sleep pattern and practice aerobic exercise. Certain medicines may help prevent attacks of migrainous vertigo or make them less uncomfortable by providing relief for nausea and vomiting.
Anatomy of the Balance System
The ability to maintain balance depends on information that the brain receives from three different sources—the eyes, the muscles and joints, and the vestibular organs in the inner ears. All three of these sources send information in the form of nerve impulses from sensory receptors, special nerve endings, to your brain.
Each inner ear has a hearing (auditory) component—the cochlea, and a balance (vestibular) component—the vestibular system, consisting of three semicircular canals and a utricle and saccule. Each of the semicircular canals is located in a different plane in space. They are located at right angles to each other and to those on the opposite side of the head.
Inside each fluid-filled semicircular canal is a sensory receptor (cupula) attached at its base. When the head moves, fluid within the semicircular canals stimulates the cupula and the receptor then sends impulses to the brain about the direction of the movement. The utricle and saccule work in similar ways. They are structures that consist of sensory cells that are embedded in a gelatinous structure. Sitting on the gelatinous portion are calcium carbonate crystals called otoconia. When your body moves up and down or forward and backward, the added mass of the otoconia cause the sensory cells to bend. This sends impulses to the brain about the direction of the movement.
When the vestibular apparatus on both sides of the head are functioning properly, they send symmetrical impulses to the brain. That is, the impulses coming from the right side agree with the impulses coming from the left side.
All of the sensory input concerning balance, from the eyes, from the muscles and joints, and from the two sides of the vestibular system, is sent to the brainstem, where it is sorted out and integrated with contributions from other parts of the brain.
As integration of all the sensory input takes place, the brainstem sends out impulses along motor-nerve fibers that begin in the brainstem and end in the muscles. These muscles make your head and neck, your eyes, your legs, and the rest of your body move and allow you to maintain your balance and have clear vision while you are moving.