Vertigo

Essentials of Diagnosis

• Either a sensation of motion when there is no motion or an exaggerated sense of motion in response to movement

• Duration of vertigo episodes and association with hearing loss

• Must differentiate peripheral from central causes of vestibular dysfunction

• Peripheral: Onset is sudden; often associated with tinnitus and hearing loss; horizontal nystagmus may be present

• Central: Onset is gradual; no associated auditory symptoms

• Evaluation includes audiogram and electronystagmography (ENG) or videonystagmography (VNG) and MRI

General Considerations

• Causes can be determined based on the duration of symptoms (seconds, hours, days, months) and whether auditory symptoms are present (Table 8–3)

• Vertigo can occur as a side effect of

  • Anticonvulsants (eg, phenytoin)

  • Antibiotics (eg, aminoglycosides, doxycycline, metronidazole)

  • Hypnotics (eg, diazepam)

  • Analgesics (eg, aspirin)

  • Tranquilizing drugs and alcohol

Positioning vertigo

• Commonly known as benign paroxysmal positioning vertigo (BPPV) or benign positioning vertigo (BPV)

• Associated with changes in head position, often rolling over in bed

Endolymphatic hydrops (Ménière disease)

• Cause is unknown

• Distention of the endolymphatic compartment of the inner ear may be part of pathogenesis of this disorder

• Two known causes are syphilis and head trauma

Symptoms and Signs

• See Table 8–3

• A thorough history often narrows, if not confirms, the diagnosis

• Triggers should also be sought

  • Diet (eg, high salt in Ménière disease)

  • Stress

  • Fatigue

  • Bright lights

• Perform Romberg test; evaluate gait; observe for nystagmus

Peripheral vestibulopathy

• Vertigo usually sudden; may be so severe that patient is unable to walk or stand; frequently accompanied by nausea and vomiting

• Tinnitus and hearing loss may accompany; support otologic origin

• Nystagmus usually horizontal with rotary component; fast phase usually beats away from diseased side

• Visual fixation tends to inhibit nystagmus except in very acute peripheral lesions or with CNS disease

• Dix-Hallpike test

  • Patient is quickly lowered into supine position with head extending over the edge and placed 30 degrees lower than the body, turned either to left or right

  • Elicits delayed onset (about 10 s) of fatiguable nystagmus in cases of benign positioning vertigo

  • Nonfatiguable nystagmus indicates central etiology for dizziness

• Subtle forms of nystagmus may be observed by using Frenzel goggles, which prevent visual fixation

• Fukuda test can demonstrate vestibular asymmetry when the patient steps in place with eyes closed and consistently rotates

• Positional vertigo

  • Typical symptoms occur in clusters that persist for several days

  • A brief latency period (10–15 s) follows head movement before symptoms develop

  • Acute vertigo subsides within 10–60 s, but patient may remain imbalanced for several hours

  • Constant repetition of positional change leads to habituation

  • In central lesions, there is no latent period, fatigability, or habituation

• Ménière syndrome

  • Classic syndrome consists of episodic vertigo, with discrete vertigo spells lasting 20 min to several hours in association with

    • Fluctuating low-frequency sensorineural hearing loss

    • Tinnitus (usually low-tone and "blowing" in quality)

    • Sensation of unilateral aural pressure

  • Symptoms wax and wane as endolymphatic pressure rises and falls

  • Caloric testing commonly reveals loss or impairment of thermally induced nystagmus on the involved side

• Labyrinthitis

  • Acute onset of continuous, usually severe vertigo lasting several days to a week, hearing loss, tinnitus

  • During recovery (several weeks), vertigo gradually improves

  • Hearing may return to normal or be permanently impaired in involved ear

Central vestibulopathy

• Vertigo of central origin often becomes unremitting and disabling

• CNS causes of vertigo include

  • Brainstem vascular disease

  • Arteriovenous malformations

  • Tumor of the brainstem and cerebellum

  • Multiple sclerosis

  • Vertebrobasilar migraine

• Nystagmus

  • Not always present but can occur in any direction and may be dissociated in both eyes

  • Often nonfatigable, vertical rather than horizontal, without latency, unsuppressed by visual fixation

Differential Diagnosis

• Imbalance

• Light-headedness

• Syncope

Imaging Studies

• MRI to evaluate persistent vertigo or when central nervous system disease is suspected

Diagnostic Procedures

• Audiologic evaluation, caloric stimulation, ENG, VNG, vestibular-evoked myogenic potentials are indicated in patients with persistent vertigo or when central nervous system disease is suspected

• ENG is helpful in quantifying the degree of vestibular hypofunction

• Vestibular-evoked myogenic potentials help distinguish between central and peripheral lesions and to identify causes requiring specific therapy

Medications

• Diazepam or meclizine

  • For acute phases of vertigo only

  • Discontinue as soon as feasible to avoid long-term dysequilibrium

• Ménière disease

  • Low-salt diet

  • Diuretics (eg, acetazolamide)

  • For acute attacks, oral meclizine (25 mg) or valium (5 mg)

• Labyrinthitis

  • Antibiotics if patient is febrile or has symptoms of bacterial infection

  • Vestibular suppressants (eg, oral diazepam, 5 mg or oral meclizine, 25 mg)

Therapeutic Procedures

• Positioning vertigo: involves physical therapy protocols (eg, the Epley maneuver or Brandt-Daroff exercises)

• For refractory cases of Ménière disease

  • Intratympanic corticosteroid injections

  • Endolymphatic sac decompression

  • Vestibular ablation either through transtympanic gentamicin, vestibular nerve section, or surgical labyrinthectomy

When to Refer

• Audiologic evaluation, caloric stimulation, ENG, VNG, and MRI are indicated in patients with persistent vertigo or when CNS disease is suspected