Conditions & treatments - Audiology > Dizziness & Vertigo
Vertigo, or dizziness, usually results from a disorder in the peripheral vestibular system (i.e., structures of the inner ear). Dizziness also may occur as a result of a disorder in the central vestibular system (i.e., vestibular nerve, brainstem, and cerebellum). In some cases, the cause of vertigo is unknown.
Benign paroxysmal positional vertigo (BPPV) usually affects one of the sensing tubes in the inner ear called the posterior semicircular canal. BPPV occurs when debris made up of calcium carbonate and protein (called otoliths or ear crystals) builds up in and moves around in the posterior semicircular canal. BPPV also can affect the anterior canal or the horizontal canal.
When the head is moved in certain ways (e.g., turning in bed, looking up, bending over), the calcium crystals move around and trigger inner ear sensors, causing a brief sensation of spinning. Inner ear degeneration (usually occurs in elderly patients), head trauma, and inner ear infection (e.g., otitis media, labyrinthitis) can cause BPPV. (See Epley Maneuver)
Some medications and environmental chemicals (e.g., lead, mercury, tin) can cause ototoxicity (i.e., ear poisoning), which may result in damage to the inner ear or the 8th cranial nerve (acoustic nerve) and cause vertigo. The damage can be permanent or temporary.
Long-term use or high doses of certain antibiotics (e.g., aminoglycosides [streptomycin, gentamicin]) and antineoplastics (e.g., cisplatin, carboplatin) can cause permanent ototoxicity.
• Anticonvulsants (e.g., phenytoin, carbamazepine)
• Antidepressants (e.g., clomipramine, amoxapine)
• Antihypertensives (e.g., labetalol, enalapril)
• Loop diuretics (e.g., bumetanide, furosemide)
• Pain relievers (e.g., aspirin)
• Prescription and over-the-counter cold medicines
• Quinine (e.g., chloroquine, quinidine)
Alcohol, even in small amounts, can cause temporary vertigo in some people.
Vestibular rehabilitation therapy (VRT) is a type of physical therapy used to treat vertigo. The goal of treatment is to minimize dizziness, improve balance, and prevent falls by restoring normal function of the vestibular system.
In VRT, the patient performs exercises designed to allow the brain to adapt to and compensate for whatever is causing the vertigo.
The success of this treatment depends on several factors including the following:
• Age of the patient
• Cognitive function (e.g., memory, ability to follow directions in order)
• Coordination and motor skills
• Overall health of the patient (including the central nervous system)
• Physical strength
Vestibular rehabilitation therapy is designed by a physical therapist under the direction of a physician. In most cases, patients visit the therapist on a limited basis and perform custom-designed exercises at home, several times a day. As the patient progresses, difficulty of the exercises increases until the highest level of balance is attained during head movement, eye movement (i.e., tracking with the eyes), and walking.
According to the American Academy of Neurology, the most effective treatment for benign paroxysmal positional vertigo (BPPV) caused by ear crystals in the posterior semicircular canal, is a technique called the canalith repositioning procedure, or the Epley maneuver.
In this procedure, a physician or physical therapist assists the patient in performing a series of head and body movements, which move the calcium crystals out from the posterior semicircular canal and into another inner ear canal, where it is absorbed by the body. Another technique (called the Semont maneuver) also may be effective, but additional studies are needed.
BPPV that does not respond to canalith repositioning may be treated with meclizine (Antivert®), an oral antiemetic that can be taken up to 3 times a day, or only as needed. Meclizine may cause drowsiness, dry mouth, and blurred vision.
The Epley Maneuvers, also known as the Canalith Repositioning Procedure (CRP), are designed to treat benign paroxysmal positional vertigo (BPPV) through induced out-migration of free-moving pathological densities in the endolymph of a semicircular canal, using timed head maneuvers and applied vibration.
In simpler terms, canaliths (calcium carbonate crystals) are normally attached atop a membrane in the otolith organ (or gravity center) of the inner ear. These crystals can break off for various reasons, most commonly, injury or disease, and migrate into a semicircular canal. Then, when the head position is changed, the canaliths shift, abnormally stimulating the nerve sensor (cupula) of the affected semicircular canal and creating a sensation of movement (vertigo). In treatment, the head is maneuvered so as to guide the canaliths (also referred to as otoliths or cupuloliths, depending on their placement) back though the labyrinth to where they originated. To facilitate this process, the canaliths can be tracked by observing the eye movements they cause, and by applying an oscillator to the skull. In most medical facilities, this maneuvering is done by hand with the patient lying on a table.