Vertigo (Dizziness)
Overview
Vertigo, or dizziness, is a symptom, not a disease. The term vertigo refers to the sensation of spinning or whirling that occurs as a result of a disturbance in balance (equilibrium). It also may be used to describe feelings of dizziness, lightheadedness, faintness, and unsteadiness. The sensation of movement is called subjective vertigo and the perception of movement in surrounding objects is called objective vertigo.
Vertigo usually occurs as a result of a disorder in the vestibular system (i.e., structures of the inner ear, the vestibular nerve, brainstem, and cerebellum). The vestibular system is responsible for integrating sensory stimuli and movement and for keeping objects in visual focus as the body moves.
When the head moves, signals are transmitted to the labyrinth, which is an apparatus in the inner ear that is made up of three semicircular canals surrounded by fluid. The labyrinth then transmits movement information to the vestibular nerve and the vestibular nerve carries the information to the brainstem and cerebellum (areas of the brain that control balance, posture, and motor coordination). There are a number of different causes for dizzy spells.
Incidence and Prevalence
Vertigo is one of the most common health problems in adults. According to the National Institutes of Health (NIH), about 40% of people in the United States experience feeling dizzy at least once during their lifetime. Prevalence is slightly higher in women and increases with age.
Signs and Symptoms
Vertigo, or dizziness, refers to the sensation of spinning (subjective vertigo) or the perception that surrounding objects are moving or spinning (objective vertigo). Some patients describe a feeling of being pulled toward the floor or toward one side of the room. Moving the head, changing position, and turning while lying down often worsen vertigo.
The sudden onset of vertigo usually indicates a peripheral vestibular disorder (e.g., BPPV, Ménière disease, vestibular neuritis).
Symptoms of benign paroxysmal positional vertigo (BPPV) usually last a few seconds to a few minutes and are intermittent (i.e., come and go). They also may include lightheadedness, imbalance, and nausea, usually as a result of a change in position (e.g., rolling over in bed, getting out of bed).
Symptoms of Meniere disease and vestibular neuritis include vertigo, hearing loss, ringing in the ears (tinnitus), and ear pressure that often lasts hours to days.
Peripheral vestibular disorders also may cause the following symptoms:
- Blurred vision
- Fatigue and reduced stamina
- Headache
- Heart palpitations (rapid fluttering of the heart)
- Imbalance
- Inability to concentrate
- Increased risk for motion sickness
- Muscle ache (especially of the neck and back)
- Nausea and vomiting
- Reduced cognitive function (i.e., thinking and memory)
- Sensitivity to bright lights and noise
- Sweating
Vertigo caused by a central vestibular disorder usually develops gradually. In addition to vertigo, central vestibular disorders (e.g., stroke [brain attack], migraine) may cause the following symptoms:
- Double vision (diplopia)
- Headache (may be severe)
- Impaired consciousness
- Inability to speak due to muscle impairment (dysarthria)
- Lack of coordination
- Nausea and vomiting
- Weakness
Complications
Severe vertigo can be disabling and may result in complications such as irritability, loss of self-esteem, depression, and injuries from falls. Falls are the leading cause of serious injury in people over the age of 65.
Causes
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.
Peripheral vestibular disorders include the following:
- Benign paroxysmal positional vertigo (BPPV; most common peripheral disorder; may be accompanied by hearing loss, reduced cognitive function, and facial muscle weakness)
- Cogan's syndrome (inflammation of connective tissue in the cornea; results in vertigo, ringing in the ears [tinnitus], and loss of hearing)
- Ménière disease (fluctuating pressure of inner ear fluid [endolymph]; results in severe vertigo, ringing in the ears [tinnitus], and progressive hearing loss)
- Ototoxicity (i.e., ear poisoning)
- Vestibular neuritis (inflammation of vestibular nerve cells; may be caused by viral infection)
Benign paroxysmal positional vertigo occurs when debris made up of calcium carbonate and protein (called otoliths or ear crystals) builds up in and damages the inner ear. Inner ear degeneration (usually occurs in elderly patients), head trauma, and inner ear infection (e.g., otitis media, labyrinthitis) can cause BPPV.
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.
Medications that may cause temporary ototoxicity include the following:
- 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.
Central vestibular disorders that may cause vertigo include the following:
- Cardiovascular disorders (e.g., bradycardia [slowed heart rate], tachycardia [rapid heart rate])
- Central nervous system (CNS) disorders (e.g., stroke [brain attack], brain hemorrhage)
- Head trauma
- Migraine (30-50% of patients experience vertigo)
- Multiple sclerosis (MS; may occur when demyelination affects the brainstem or cerebellum)
- Orthostatic hypotension (sharp decrease in blood pressure upon rising from a lying or sitting position to a standing position; caused by diabetes, dehydration, and anemia)
- Systemic diseases (e.g., kidney disease, thyroid disorders)
- Tumors that affect the central vestibular system (e.g., acoustic neuroma)
Diagnosis
It is important to diagnose the cause of vertigo, or dizziness, as quickly as possible to rule out serious conditions such as cardiovascular disease, stroke, hemorrhage, or tumor. Diagnosis includes clinical history, physical and neurological examination, blood tests, and imaging tests (e.g., CT scan, MRI scan).
Important considerations include the following:
- What triggers the vertigo?
- What other symptoms occur?
- How long does the dizziness last?
- What improves or worsens symptoms?
Physical examination includes measuring blood pressure and heart rate. Neurological examination includes testing facial and vestibular nerves and muscles, strength, coordination, balance, and walking (gait).
The positional vertigo test is used to help distinguish peripheral from central vestibular disorders. In this test, the patient sits on a table with the head turned to the side. The physician then supports the head and lowers it gently below the table while the patient lies back. The patient reports symptoms of vertigo while the physician looks for circular movement of the eyes (called nystagmus).
A delay between the onset of nystagmus and the sensation of vertigo usually indicates a peripheral vestibular disorder. Lack of a delay may indicate a central vestibular disorder. The test is repeated with the head turned in the opposite direction.
Electronystagmography (ENG) is a neurological test used to evaluate the vestibular system. It involves testing hearing in both ears (audiometry tests), testing eye movements, and evaluating responses to changes in posture and position.
Blood tests include a complete blood count (CBC) and kidney and thyroid panels to rule out systemic diseases (e.g., kidney disease, hypothyroidism). If the patient is taking medication, drug levels are obtained.
Imaging tests may be used to detect brain abnormalities (e.g., stroke, tumor). Computed tomography (CT scan) produces x-ray images of the brain and magnetic resonance imaging (MRI scan) uses a magnetic field to produce detailed images of brain tissue and arteries in the neck and brain.
Treatment
Treatment for vertigo, or dizziness, depends on identifying and eliminating the underlying cause. If a particular medication is responsible for the condition, lowering the dosage or discontinuing the drug may eliminate vertigo.
Vestibular Rehabilitation Therapy
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.
Medication
Ear infections (e.g., otitis media, labyrinthitis) caused by bacteria may be treated using antibiotics (e.g., amoxicillin, ceftriaxone). Myringotomy is a surgical procedure that may be used to treat chronic ear infections. In this procedure, which is performed under anesthesia, an incision is made in the eardrum and a small tube is placed in the opening to prevent fluid and bacteria from building up inside the ear.
Benign paroxysmal positional vertigo 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.
If meclizine is ineffective, benzodiazepines such as clonazepam (Klonopin®) or antihistamines such as promethazine (Phenergan®) may be prescribed. Side effects of clonazepam include drowsiness, lack of coordination (ataxia), and confusion. Promethazine may cause drowsiness, fatigue, insomnia, and tremors.
Ménière disease may be treated by reducing sodium (salt) intake and with diuretic medications. A short, tapered course of corticosteroids (e.g., prednisone) may be prescribed early in the disease to reduce inflammation and stabilize hearing. Antibiotics (e.g., gentamicin) may be administered into the middle ear (called intratympanic perfusion) to treat severe vertigo caused by Ménière disease.
Vertigo caused by migraine can often be treated with medication.
Cerebrovascular disease (stroke), tumors, and multiple sclerosis may require treatment with medication, radiation, or surgery.
Prognosis
Prognosis depends on the cause of the vertigo and how well the underlying condition responds to treatment. Severe vertigo can be permanently disabling, especially in elderly patients. Peripheral vestibular disorders may cause progressive hearing loss.