Vertigo

Introduction

            VERTIGO is a false sense of motion.  People usually describe vertigo as a sensation in which they feel they are spinning, or that their environment is spinning around them.  Of the four types of dizziness—vertigo, lightheadedness, presyncope (near-fainting), and dysequilibrium (imbalance)—vertigo is the most common type for which patients seek medical care.  Over half the patients who go to the doctor for dizziness complain of vertigo [1]. 

What causes vertigo?

            Doctors usually separate the causes of vertigo into three main categories:  peripheral vertigo, caused by disorders of the peripheral nervous system (the part of the nervous system that lies outside the brain and spinal cord); central vertigo, caused by disorders of the central nervous system (the part of the nervous system that includes the brain and spinal cord); and other causes (disorders involving other systems of the body, medications, psychological causes, etc.).

PERIPHERAL VERTIGO

            Peripheral nervous system disorders cause most cases of vertigo that are seen by health care providers.  The most common of these are benign paroxysmal positional vertigo (BPPV), acute vestibular neuronitis (AVN), and Ménière’s disease.  These three disorders account for thirty-five to fifty-five percent of all patients with dizziness [2], and ninety-three percent of patients with peripheral vertigo [3].

            Benign paroxysmal positional vertigo (BPPV), also called benign positional vertigo (BPV), is a condition that typically causes brief episodes of intense vertigo with changes in head position.  Normally, head motion causes a current to form in the fluid (endolymph) in the semicircular canals that lie in the inner ear (Figure 1).  The flow of endolymph over vestibular sense organs (ampullae) inside the semicircular canals sends signals through the vestibular nerve to the area of the brain that is responsible for processing these signals and interpreting them as the direction and speed of movement (Figure 2).  In BPPV, a small stone (canalith) breaks away from the utricle, migrates through one of the semicircular canals and abnormally stimulates the vestibular sense organ at the ampulla, causing a false rotatory sense of movement.   BPPV affects twice as many women as men, and 64 cases of BPPV occur per year in every 100,000 people, with more cases occurring in middle-aged and older patients [4].

             Acute vestibular neuronitis (AVN) (also called vestibular neuritis) is caused by inflammation of the vestibular nerve, usually by viral infections.  Patients typically experience severe vertigo, often with nausea and vomiting, for several hours to days.  There is much confusion about the name of this condition.  Often, the term “labyrinthitis” is used interchangeably.  However, labyrinthitis, or inflammation of the semicircular canals due to infection, is distinct from AVN, which refers to inflammation of the vestibular nerve.

            Ménière’s disease (also known as Ménière’s syndrome or endolymphatic hydrops) is thought to be caused by swelling of the endolymphatic sac (Figure 3), which controls the filtration and excretion of endolymph.  The endolymphatic sac is connected to the vestibular sense organs by the vestibular aqueduct.  No one is sure what exactly causes the swelling.  Patients with Ménière’s disease experience recurrent vertigo typically lasting hours.  They also develop sensorineural hearing loss (hearing loss resulting from nerve problems rather than sound transmission problems), tinnitus (ringing or other sounds in the ears), and/or a sensation of fullness in the ears.

            Other less common disorders causing peripheral vertigo include labyrinthitis, perilymphatic fistula, cholesteatoma, herpes zoster oticus, and otosclerosis.

             Labyrinthitis is caused by acute or chronic inflammation of the semicircular canals from viral or bacterial infection.  The symptoms of labyrinthitis are the same as AVN, except that patients with labyrinthitis also experience tinnitus and/or hearing loss.

            A perilymphatic fistula is a breach in the membrane between the middle and inner ear.  Endolymph from the vestibular organs leaks through this breach, causing vertigo and hearing loss. The condition often results from some kind of trauma, such as a direct blow to head, barotrauma (damage caused by sudden changes in air pressure, as may be experienced by scuba divers), loud noise, or excessive straining as with heavy weight bearing or bowel movements.  Sneezing or movements that result in the affected ear pointing downward can provoke vertigo in patients with perilymphatic fistulas.

            A cholesteatoma is a benign, cystlike growth filled with keratin (a protein that forms the outer layer of skin).  It most often grows in the middle ear and mastoid (the part of the skull just behind the ear).

            Herpes zoster oticus (also known as “Ramsay-Hunt syndrome”) is caused by reactivation of the varicella-zoster virus (VZV), the virus that causes chicken pox.  After this virus causes a chicken pox infection, it lies dormant in a cranial or spinal nerve.  Later in life, the virus may reactivate, causing herpes zoster (shingles), a painful rash of fluid-filled vesicles that eventually erupt, leaving a cluster of sores.  In herpes zoster oticus, VZV infects the facial nerve (also known as the seventh cranial nerve), and vesicles erupt in the ear as a result.

            Otosclerosis is caused by abnormal growth of bone in the middle ear.  This decreases the mobility of the bones in the middle ear (stapes, hammer, and anvil) which transmit sound from the eardrum to the cochlea (the organ in the inner ear that converts sound energy to nerve impulses).

            Otosclerosis and cholesteatoma cause a type of hearing loss called conductive hearing loss, because they decrease the conduction of sound within the ear.  This is distinct from sensorineural hearing loss, which is described above.

CENTRAL VERTIGO

            Central nervous system disorders are less common causes of vertigo.  These include cerebrovascular ischemia (insufficient blood flow to part of the brain), tumors, migraine, and multiple sclerosis (MS).

            Patients with cerebrovascular disease have partial or complete blockages in the arteries that supply the brain with blood.  These blockages can cause a temporary loss of blood flow (called transient ischemic attack, or TIA for short), or permanent loss of blood flow (called stroke; also called cerebrovascular accident, or CVA).  Strokes can also be accompanied by bleeding into the brain tissue (hemorrhagic strokes).  Cerebrovascular disease affecting the vertebral and basilar arteries is the most common causes of central vertigo.  These arteries supply blood to areas in the posterior part of the brain that control balance and coordination.  Impaired blood flow through these arteries is called vertebrobasilar insufficiency (VBI).  Patients with VBI may complain of headache, numbness, weakness, tingling, and difficulty walking (ataxia).  VBI and other causes of cerebrovascular ischemia or stroke account for about five percent of cases of dizziness altogether [2].

            Tumors are uncommon causes of vertigo.  Tumors most likely to cause vertigo arise from a region of the brain called the cerebellopontine angle, which lies between two parts of the brain called the cerebellum and the pons.  These tumors are also referred to as posterior fossa tumors, based on their location in the posterior fossa of the skull.  The most common type of these tumors is acoustic neuroma (also known as vestibular schwannoma).  This tumor can cause vertigo, tinnitus, and/or unilateral hearing loss.  Other tumors include gliomas and medulloblastomas (two types of malignant brain tumors), and neurofibromatosis (a genetic condition that causes abnormal growths to form along nerves).

            Migraine is a condition that usually causes episodic, unilateral, throbbing headaches.  Sometimes people with migraine also have nausea, vomiting, photophobia (worsening with bright light) and phonophobia (worsening pain with loud noise).  In patients with classical migraine, a set of symptoms called an “aura” occur before the headache starts.  The aura varies individually, but many patients describe seeing flashing lights.  Migraine without aura is called common migraine.  Twenty-one to thirty-five percent of patients with migraine suffer vertigo [5].

            Multiple sclerosis (MS) is a disease caused by demyelinization of white matter in the central nervous system.  Myelin is a substance in nerve tissue that is necessary for neurons to transmit electrical signals quickly.  In MS the body’s own immune system attacks and destroys myelin, which affects the flow of electrical signals through nerves.  Vertigo is among the many symptoms that MS can cause.

OTHER CAUSES OF VERTIGO

            Overall, medications cause two to ten percent of all cases of dizziness [2].  Many different types of drugs can cause vertigo.  Some, termed ototoxic drugs, such as aminoglycosides (a class of antibiotics), cause vertigo by damaging the vestibular organs, which are located in the inner ear and are responsible for sensing balance.  Some of the most common drugs causing vertigo [6, 7] include:

·        Alcohol

·        Aminoglycosides

·        Anticonvulsants (such as phenytoin [Dilantin])

·        Antidepressants

·        Antihypertensives

·        Barbiturates

·        Cocaine

·        Diuretics (such as furosemide [Lasix])

·        Nitroglycerin

·        Quinine

·        Salicylates

·        Sedatives/hypnotics (such as diazepam [Valium])

            Psychological causes of vertigo include mood disorders such as depression, anxiety disorders, somatization disorders, personality disorders, and alcohol abuse.  Patients with depression may be sad, unable to enjoy activities, find it hard to concentrate and motivate themselves to do things, and may not sleep or eat well.  Patients with anxiety may experience constant worry or stress, sleep disturbances, and panic attacks, among other symptoms.  Patients who associate dizziness with panic attacks usually describe their dizziness as vertigo [8].  In primary care patients with dizziness, 4-17% have dizziness primarily caused by psychological conditions [9, 10] and up to 25% of patients have a psychological component to their dizziness [11].  The percentage of patients specifically with vertigo of psychiatric origin is unknown.

             Cervical vertigo is defined as vertigo triggered by head and neck movements. However, some doctors do not believe this condition actually exists, and most patients in whom this diagnosis is considered should have other, more well-established diagnoses considered first.

OTHER CONSIDERATIONS

            Cardiovascular disease such as atherosclerosis (blockages of the arteries), congestive heart failure, and arrhythmias (abnormal heart rhythms) may cause vertigo indirectly by decreasing the amount of blood flowing to the brain.  However, these conditions are usually more associated with a type of dizziness called “presyncope” (feeling faint).

            Uncommon causes of vertigo and dizziness include substance abuse, metabolic abnormalities, hepatic encephalopathy (brain or psychiatric abnormalities in patients with liver disease), electrolyte disturbances, systemic and upper respiratory infections, hypertension, trauma, anemia, Alzheimer’s disease, Parkinson’s disease, seizures, and endocrine disorders [2].

VERTIGO IN CHILDREN

            The most common causes of vertigo in children include otitis media (infections of the middle ear, the part of the ear behind the eardrum), chronic middle ear effusion (fluid that collects in the middle ear), and Eustachian tube dysfunction [12].  Less common causes of vertigo in children include benign paroxysmal positional vertigo of childhood, migraine, trauma, vestibular neuronitis, and Ménière’s disease [13].

How is vertigo diagnosed?

            Determining the cause of vertigo can be very challenging.  Not only are there a multitude of causes of vertigo, but the symptom of dizziness itself is often difficult for people to describe.  Also, some forms of dizziness may overlap or coexist, further complicating the diagnosis.  Multiple causes of vertigo are common, especially in older patients.  Some tests that are used to diagnose vertigo may be not as useful in older people, in whom dizziness and vertigo are more common.  Even when patients with dizziness are referred to specialists, about ten to twenty-five percent of these patients still do not have a definitive diagnosis at the end of their diagnostic workup [2].

            One study determined that asking patients if their dizziness felt like the world spinning around them accurately detected patients with true vertigo if they answered yes [14].  Once the presence of true vertigo versus another form of dizziness is confirmed, there are some strategies that can help distinguish between the many causes of vertigo.  Although there are several diagnostic physical, laboratory, and radiological (imaging) tests for distinguishing one form of vertigo from another, the most important part of diagnosing vertigo is how one describes it.  This description alone, without the use of laboratory or x-ray tests, reveals the diagnosis in roughly three of four patients complaining of dizziness, although the exact proportion in patients specifically complaining of vertigo is unknown [2].

HISTORY

            Important aspects of the description to note include:

·        Quality of symptoms (a description of the vertigo itself)

·        Timing and duration of vertigo

·        Severity of vertigo over time

·        What makes the vertigo better or worse (triggers)

·        Associated symptoms

·        Chronic medical conditions and psychological problems

·        Risk factors for vascular disease

·        Medication use

            As noted above, conditions that cause vertigo can be grouped by peripheral vestibular causes (those originating in the peripheral nervous system), central vestibular causes (those originating in the central nervous system), and other conditions.  The key initial task is to determine which category of vertigo one is most likely to fall under, keeping in mind that more than one condition causing vertigo may exist.  Further, each individual cause of vertigo has a typical set of symptoms and signs that can further help distinguish it from other causes.

            The following are some key differences between peripheral and central vestibular disorders, as well as some unique characteristics of individual causes of vertigo:

Quality of symptoms.  Rotatory illusions (a sense of spinning) are highly associated with peripheral vertigo, especially when accompanied by nausea and/or vomiting.  In patients who describe their dizziness as imbalance, those with peripheral vertigo have more mild or moderate symptoms and can usually walk, while those with central vertigo have more severe symptoms and may not be able to stand still or walk [15].

Timing and duration of vertigo.  Generally, the longer symptoms last, the more likely is central vertigo.  Peripheral vertigo generally has more sudden onset than central vertigo, unless the cause is a stroke or TIA.  A scheme used to differentiate between BPPV, vestibular neuronitis, labyrinthitis, or Ménière’s disease based on the presence or absence of hearing loss, and whether vertigo was episodic or persistent, resulted in a correct diagnosis 60% of the time.  According to this scheme, patients with episodic vertigo without hearing loss were diagnosed with BPPV; episodic vertigo and hearing loss, Ménière’s disease; persistent vertigo without hearing loss, vestibular neuronitis; and persistent vertigo with hearing loss, labyrinthitis [16].

Severity of vertigo over time.  In AVN symptoms typically are severe initially but lessen over the next few days.  In Ménière’s disease attacks of vertigo are more severe earlier in the course of the disease than later.  They may last several seconds to a few minutes in BPPV.  Patients with perilymphatic fistulas and posterior TIAs can have vertigo lasting a few minutes to hours, with longer episodes more likely if the perilymphatic fistula resulted from trauma or surgery.  Episodes typically last for hours in Ménière’s disease, migraine, and acoustic neuroma.   Vertigo can last constantly for days in early AVN (from a few days up to a week or more), stroke, migraine, and multiple sclerosis.  Constant vertigo lasting for weeks may be primarily psychological in origin.

Triggers.  Knowing what provokes vertigo may help determine the cause.  Changes in position causing vertigo such as turning over in bed, bending over at the waist and then straightening up, or tilting the head back suggest BPPV as the cause.  Other causes of vertigo provoked by changes in head position include acute labyrinthitis, cerebellopontine angle tumors, multiple sclerosis, and perilymphatic fistulas.   A recent viral upper respiratory infection suggests AVN or acute labyrinthitis.  A patient who experiences “Tullio’s phenomenon” (vertigo caused by loud noises or sounds at a particular frequency) is more likely to have peripheral vertigo [17].  Stress or other triggers can cause migraine and thus migraine-associated vertigo.  Stress, anxiety or panic attacks may cause hyperventilation, which could cause vertigo.  Vertigo associated with changes in ear pressure, head trauma, excessive straining, and/or loud noises may be caused by perilymphatic fistula.  Conditions that trigger herpes zoster (stress and immunosuppression, for example) may cause herpes zoster oticus (Ramsay-Hunt syndrome), which can cause vertigo.   Many conditions (including AVN, stroke, transient ischemic attack, Ménière’s disease, migraine, and multiple sclerosis) can cause spontaneous vertigo without any consistent triggers.

Associated symptoms.  The most useful symptoms for determining the cause of vertigo are nausea and vomiting, pain, hearing loss, tinnitus, and other neurological symptoms.

Nausea and vomiting.  In AVN and in severe episodes of Ménière’s disease and BPPV, patients may have nausea and vomiting.  These symptoms are usually more severe than in central vertigo.

Headache.  Vertigo with headache suggests migraine or a tumor in the cerebellopontine angle (the area between the parts of the brain called the cerebellum and the pons), such as acoustic neuroma.

Ear Pain.  Vertigo with ear pain suggests middle ear disease such as a middle ear infection (otitis media) or herpes zoster oticus (shingles affecting the eardrum; Ramsay-Hunt syndrome).  Less common causes of vertigo with ear pain include acoustic neuroma, infection or tumor invading the temporal bone of the skull, or conditions that cause irritation of the meninges (the membranes covering the brain and spinal cord), such as meningitis.

Hearing Loss and Tinnitus.  Hearing loss and tinnitus (ringing in the ears) are more common in peripheral vertigo than in central vertigo.

Hearing Loss.  Most causes of vertigo with hearing loss are peripheral, either labyrinthitis or Ménière’s disease.  There is a characteristic course of hearing loss in Ménière’s disease.  Early in the disease, hearing loss affects lower frequencies and fluctuates; later, hearing loss progressively worsens, and affects higher frequencies.  Perilymphatic fistulas, cholesteatomas, and otosclerosis can cause progressively worsening hearing loss.  Herpes zoster oticus can cause hearing loss of acute or subacute onset (over the course of a few days).  Causes of central vertigo associated with hearing loss include (1) acoustic neuroma, which causes a progressive, unilateral hearing loss, and (2) stroke or TIA involving the anterior inferior cerebellar artery, which supplies blood to one of the areas of the brain responsible for sensing balance.  A stroke in this area typically causes sudden onset of vertigo and hearing loss in one ear.

Tinnitus.  Conditions causing vertigo and tinnitus include acute labyrinthitis, acoustic neuroma, and Ménière’s disease.

Other neurological symptoms. Such symptoms as weakness, dysarthria (difficulty speaking), vision changes, paresthesia (abnormal tactile sensations, such as a feeling of “pins and needles”), altered level of consciousness, abnormal gait or other changes in sensory and motor function suggest central vertigo.  Facial weakness is associated with acoustic neuroma and herpes zoster oticus.  A feeling of fullness in the ears can be caused by acoustic neuroma or Ménière’s disease.  Imbalance can be caused by AVN (usually moderate) or acoustic neuroma (usually severe).  Vertigo associated with intolerance of loud noises or bright light suggests migraine as the cause, especially when accompanied by headache.

Other important clues to the diagnosis of vertigo may come from the past medical and psychiatric history, including medications, trauma, and exposure to toxins.  Age is associated with some conditions underlying vertigo.  For example, elderly patients, especially those with diabetes or hypertension, are at higher risk of cerebrovascular causes of vertigo.  A history of hereditary conditions in the family, such as migraine and risk factors for vascular disease, may also help with the diagnosis.

PHYSICAL EXAMINATION

            There can be important clues to the cause of vertigo from the physical examination, especially of the neurological, head and neck, and cardiovascular systems.

Neurological Exam

            On neurological exam, abnormalities in the cranial nerves, which control movements and detect sensations in the head, neck, and upper back, may give clues to the diagnosis.  For example, drooping of the facial muscles may indicate a stroke or TIA.  A test called the subjective visual vertical test may be used to determine which side is affected by a unilateral vestibular disorder.  In this test, a patient with recent onset of a unilateral vestibular disorder perceives vertical as 10-30 degrees tilted towards affected side.  The chances of detecting this finding are better shortly after the onset of the disorder, because the effect diminishes with time as the brain reorients itself [18].

As noted above, hearing loss is associated with some causes of vertigo.  The Weber and Rinne tests (see videos here) can be used to distinguish between sensorineural and conductive hearing loss.  In the Weber test, a tuning fork is placed at the midline of the skull; in unilateral sensorineural hearing loss, the tuning fork will sound louder in the unaffected ear.  In the Rinne test, the tuning fork is placed on the mastoid process (the bony region behind the ear) until the patient no longer hears the sound.  Right after the patient stops hearing the sound, the tuning fork is brought to the opening of the ear canal on the same side, and if the patient does not hear the tuning fork, there is conductive hearing loss affecting that ear.

The characteristics of nystagmus can also give valuable clues.  Nystagmus is a rhythmic movement of the eyes that is often a telltale sign of vertigo.  There is a “slow” component of movement in one direction followed by a “fast” component in the other direction.  Eye movements may be linear (either horizontally or vertically), rotational, or both.  In peripheral vertigo, nystagmus usually is horizontal and rotational, lessens or disappears when gaze is fixed on a target, fades after a few days, does not change direction with gaze to either side, and is usually triggered by something.  Nystagmus in peripheral vertigo may be detected by using an ophthalmoscope to visualize the patient’s retina in a dark room [18]. In central vertigo, nystagmus is purely horizontal, vertical, or rotational, does not lessen when gaze is fixed on a target, persists longer (weeks to months), and may change direction when the patient looks in the same direction as the eye moves in the “fast” phase of nystagmus. 

Generally, patients with peripheral vertigo may have impaired balance but are still able to walk, whereas patients with central vertigo may have more severe problems and often cannot walk or even stand without falling [15].

Mental status examination (mood, affect, and thought processes) may be abnormal in psychological disorders causing dizziness.

            The Dix-Hallpike (also known as the Nylan-Barany) maneuver (see videos of this maneuver here) may be the most helpful test to perform in patients with vertigo [3].  To perform the Dix-Hallpike maneuver, the patient sits upright with the head turned 30 to 45 degrees towards the side being tested.  The patient focuses both eyes on the examiner’s eyes or forehead.  Then, as the examiner supports the patient’s head, the patient lies supine (on their back) quickly (within two seconds), allowing the neck to hyperextend slightly and hang off the edge of the examining table 20 to 30 degrees past horizontal.  After a latency period that can last from two to twenty seconds, onset of horizontal or torsional (a repetitive twisting motion) nystagmus denotes a positive test for peripheral vertigo.  The latency period may be shorter (0-5 seconds) in patients with central vertigo.  This provoked episode of vertigo can last up to 20 to 40 seconds.  Nystagmus changes direction when the patient sits upright again.  In peripheral vertigo, the intensity of vertigo typically decreases the more times the test is repeated; this occurs less often in central vertigo.  The combination of a positive Dix-Hallpike maneuver with a history of either vertigo or vomiting is highly accurate for diagnosing peripheral vertigo [19].  If the maneuver provokes purely vertical (usually downbeat) or torsional nystagmus, without a latent period of at least a few seconds, and does not wane with repeated maneuvers, this suggests a central cause for vertigo such as a posterior fossa tumor or hemorrhage.

            Other diagnostic tests may be used to diagnose a peripheral vestibular disorder, but there is only limited evidence on these tests from studies on patients with vertigo referred to specialty clinics, and there are no studies that compare the accuracy of these tests against more sophisticated quantitative vestibular testing techniques (see below) [18].  Of these other diagnostic tests, the ones best supported by evidence for usefulness are the head thrust, head shaking nystagmus, and head shaking-visual acuity tests.

In the head thrust test, the examiner rapidly rotates patient’s head to one side 45 degrees while the patient fixes his or her gaze on a target.  If with head turns to the side the patient’s eyes jerk the other way to stay focused on the target (called a “catch-up saccade”), the patient is likely to have a unilateral vestibular disorder.

In the head shaking nystagmus test, the patient closes both eyes, vigorously turns the head back and forth horizontally for 15-30 seconds, then stops and opens both eyes.  In patients with a unilateral vestibular disorder, there is nystagmus with the fast component moving away from the affected side.  Normal subjects do not have nystagmus.

In the head shaking-visual acuity test (also called dynamic visual acuity testing), the patient’s baseline visual acuity is measured with a standard eye chart, then measured again while the patient turns the head from side to side at 60-75 cycles per minute.  Worsening of visual acuity by 3 lines or more on visual acuity chart suggests a bilateral vestibular disorder.

            Hyperventilation for thirty seconds may rule out psychological causes of vertigo associated with hyperventilation syndrome if the test is negative (no vertigo with hyperventilation after thirty seconds).  Ninety-nine percent of patients with a negative test do not have a primarily psychological cause of their vertigo [19].  Hyperventilation rarely can cause true vertigo in patients with perilymphatic fistulas or acoustic neuromas [17]. 

Head and Neck Exam

            On head and neck examination, tympanic membranes should be examined for vesicles (seen in Ramsay-Hunt syndrome) or cholesteatoma.  Hennebert’s sign (vertigo or nystagmus caused by increasing air pressure inside the ear by pushing on the opening to the ear or blowing air into the ear canal of the affected side) may diagnose perilymphatic fistula [11].  The Valsalva maneuver (bearing down as if having a bowel movement) may cause vertigo in patients with perilymphatic fistulas or anterior semicircular canal dehiscence (dislocation or tearing of one of the semicircular canals in the inner ear).

Cardiovascular Exam

            On cardiovascular examination, patients who experience vertigo upon standing are commonly checked for a condition called orthostatic hypotension (a sudden fall in blood pressure upon standing).  This is typically done by measuring the pulse and blood pressure after a patient has been lying down for a few minutes, and then again after the patient stands for a few minutes.  A drop in systolic blood pressure of 20 mm Hg or more and an increase in the pulse of 10 beats per minute or more may detect moderate or severe dehydration [20] or abnormalities in the autonomic nervous system, which is responsible for regulating blood pressure and heart rate [4].  However, there is a wide range of normal for orthostatic blood pressure and pulse measurements [21].  About 50% of all elderly patients have positive findings on orthostatic measurements [22].  Therefore, despite testing positive for orthostatic hypotension, some patients may actually have another, more significant cause for their vertigo.  In patients with orthostatic symptoms, another test, the Schellong test, has been shown to be useful in identifying patients with postural orthostatic tachycardia syndrome or neurocardiogenic syncope, two types of autonomic nervous system disorders [23].  To perform the Schellong test, the patient has a baseline blood pressure taken while seated, then has blood pressure checked while standing continuously for 10-20 minutes; a drop of 20 mg Hg or more in the systolic blood pressure denotes a positive test.

Carotid sinus stimulation (massage of the carotid artery in the neck) has low yield in identifying patients with significant arrhythmias.  The test detects only 6% in patients >60 years old with unexplained dizziness) [24], and has been shown not to be useful in the diagnosis of vertigo [14].

LABORATORY TESTS

Laboratory tests such as electrolytes, glucose, blood counts, and thyroid function tests identify the cause of dizziness in less than one percent of patients [2].  Therefore, these tests are not ordered routinely, but may be appropriate when patients with vertigo have signs or symptoms that may be due to conditions that these tests can detect.  For example, it has been suggested that glucose levels should be checked in diabetic patients with dizziness to see if low blood sugar may be the cause.  It has also been suggested that cardiac rhythm should be monitored in patients over 45 years old [19].

Cardiac arrhythmia monitoring may be done if an abnormal heart rhythm is suspected.  Types of monitoring include Holter monitors (devices that records the heart rhythm over a 24 hour period) and patient-triggered event recorders (devices that record cardiac rhythms when patients note symptoms.  Unfortunately, used alone, a Holter monitor  misses over half of relevant arrhythmias, and patient-triggered event recorders alone capture only about one-sixth of clinically relevant arrhythmias [25].  Therefore, patient-triggered event recorders with continuous automatic arrhythmia detection are preferred, because they record cardiac rhythms when patients note symptoms, as well as detect and record any other arrhythmias automatically.   

            Audiometry (hearing tests) helps establish the diagnosis of Ménière’s disease, and may distinguish Ménière’s disease from migraine-associated vertigo [26, 27].

RADIOLOGICAL TESTS

            Neuroimaging studies should be considered in patients with vertigo who have signs or symptoms of central nervous system or invasive ear disease, acute vertigo with risk factors for vascular disease, or progressive unilateral hearing loss.  Neuroimaging studies can be used to rule out extensive bacterial infections, neoplasms, or developmental abnormalities, if other symptoms suggest any one of those diagnoses.  However, they are not needed for patients with BPPV, usually are not necessary to diagnose AVN or Ménière’s disease, and are poor routine screening tests for cerebellopontine angle tumors [28].

            In general, magnetic resonance imaging (MRI) of the brain is the test of choice over computed tomography (CT) because it is better able to visualize the posterior fossa, where most brain disease causing vertigo is found.  Sometimes, the blood vessels that supply the brain with blood need to be visualized; this is usually done with magnetic resonance angiography (MRA) or conventional angiography (contrast dye is injected so that arteries can show up on a fluoroscope machine).  These studies may be useful in diagnosing vascular causes of vertigo, such as vertebrobasilar insufficiency (inadequate blood flow through the vertebral and basilar arteries, which supply the posterior part of the brain with blood).

            X-rays may aid in the diagnosis of cervical vertigo (vertigo triggered by somatosensory input – the perception of sensory stimuli from parts of the body that are not the sensory organs – from head and neck movements) in patients with a history suggesting this diagnosis.

When are patients referred to specialists for vertigo?

            Patients with vertigo in whom the diagnosis is unclear after the initial evaluation are referred to an appropriate subspecialist (otolaryngologist/head and neck surgeon, neurologist, neurootologist, or neurosurgeon) for further workup.  Further testing of the vestibular system may be needed with quantitative techniques such as electronystagmography or infrared video oculography with caloric irrigation or passive rotational testing (see below).  Patients are also referred when needing treatment requiring further subspecialty care (for example, perilymphatic fistula or tumor).

Quantitative vestibular tests

            Quantitative vestibular tests are designed to assess the vestibulo-ocular reflex (VOR).  The VOR generates eye movements that compensate for head movements and result in clear vision.  For example, it allows the eyes to fixate on a target despite head movements in various speeds or directions.  There are techniques for measuring the eye movements produced by the VOR when the vestibular system is stimulated.  There are also different techniques for vestibular stimulation.

            The most commonly used method for recording eye movements is electronystagmography, which measures changes in the electrical activity of the eye as it moves.  Another method is infrared video nystagmography, which uses infrared cameras to detect eye movements in the dark.

            Techniques for vestibular stimulation include caloric irrigation and head rotation.  Caloric irrigation is irrigation of the ear canals with either warm or cool water or air.  Head rotation is achieved by rotating the whole body in a motorized chair (rotational chair testing) or by rotation of the head alone or whole body by the examiner.

How is vertigo treated?

            The treatment of vertigo depends on underlying cause.  Some treatments are straightforward.  For example, medication-associated vertigo is usually treated by stopping the medication causing the vertigo.  Patients with tumors are referred to the appropriate surgeons and specialists for treatment, which may include surgery, radiation, or chemotherapy.

            The treatment of BPPV includes two maneuvers designed to move the canalith away from the vestibular sense organs, the Epley Maneuver (see video here) and the Semont Maneuver (see video here).  Patients can also do a set of movements called the Brandt-Daroff exercises several times daily [3].

            The treatment of AVN and labyrinthitis focuses on relieving the symptoms as these conditions normally get better with time.  The most useful medications are antinausea medications such as prochlorperazine (Compazine).  Meclizine (Antivert) is also commonly prescribed for treatment.

            No cure exists for Ménière’s disease.  Medications and a low-salt diet may be prescribed to lower the pressure within the endolymphatic sac (increased volume and pressure in the endolymphatic sac is thought to cause the disease).  Other medications may be used to decrease symptoms.  Meclizine (Antivert) or diazepam (Valium) may be prescribed to treat the symptom of vertigo; antinausea medication may be useful as well.  Surgery may be required in severe cases.

            Migraine is treated with medications to stop the headache (abortive treatment).  Pain medications such as acetaminophen (Tylenol), ibuprofen, and other non-steroidal anti-inflammatory drugs (NSAIDs), and opioid medications may be used.  Sumatriptan (Imitrex) and other related medications more specifically treat the pain caused by migraine.  Recurrent migraine headaches, if occurring frequently enough, may be prevented with propranolol (Inderal), a beta blocker; amitriptyline, a tricyclic antidepressant; or either divalproex sodium (Depakote) or valproic acid (Depakene).  Calcium-channel blockers such as verapamil (Calan) are second-line agents for migraine prophylaxis.

For More Information

Dizziness and Vertigo: Patient Education Resources on the Internet 

Information about Dizziness, Balance, and Hearing

MedlinePlus: Dizziness and Vertigo

Dizziness and Vertigo: Merck Manual Home Edition

Vertigo (Dizziness): Overview, Incidence and Prevalence

Dizziness including vertigo, feeling faint and balance problems

Vestibular Disorders Association