VERTIGO

Key Features

ESSENTIALS OF DIAGNOSIS

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

Duration of discrete vertiginous events

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)

GENERAL CONSIDERATIONS

Causes can be determined based on the duration of symptoms (seconds, hours, days, months) and whether auditory symptoms are present (Table 8–1)

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

Clinical Findings

SYMPTOMS AND SIGNS

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

– Patient walks in place with eyes closed

– Can also demonstrate vestibular asymmetry

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 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

Diagnosis

IMAGING STUDIES

MRI to evaluate central audiovestibular dysfunction

DIAGNOSTIC PROCEDURES

ENG or VNG useful in differentiating central from peripheral causes of vertigo

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

Treatment

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 and diuretics (eg, acetazolamide)

Labyrinthitis

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

– Vestibular suppressants (eg, diazepam or meclizine)

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