Evaluation of the Dizzy and Unbalanced Patient

Etiology

The etiology of dizziness is vast and varied. Broadly, it can be separated into central/neurologic, peripheral/vestibular, or cardiovascular causes. Central causes of dizziness include cerebellar or brainstem strokes or posterior circulation TIAs.[2] Peripheral causes include vestibular schwannomas, vestibular migraines, Meniere disease, benign paroxysmal positional vertigo (BPPV), bilateral vestibulopathy, or superior canal dehiscence syndrome. Cardiovascular causes include orthostatic hypotension, presyncope, vertebral artery dissection, or dysrhythmias.[1]

Epidemiology

Dizziness accounts for approximately 3 percent of emergency department visits and 3 percent of primary care visits yearly.[1] With increased age, the incidence of dizziness also increases. Dizziness symptoms are estimated to burden 15 to 20% of adults yearly, resulting in 7.5 million people seeking evaluation.[3][4] It affects females up to 3 times more than males.[3] When evaluating a dizzy/unsteady patient, it is essential to remember that their symptoms could be secondary to a Cerebellar or Brainstem stroke because about 10% present with vertigo as the only symptom.[5] Over 50% of patients with vertebral artery dissections report dizziness or vertigo symptoms.

History and Physical

Components of the history should include:

• Onset: abrupt vs. gradual
• Duration: second, minutes, days, or weeks
• Triggered or spontaneous symptoms
• Medications they are currently taking and any recent medication changes
• Alcohol or caffeine intake
• History of recent head trauma
• Associated symptoms that would suggest a central (neurologic) etiology, such as dysarthria, dysphagia, diplopia, truncal ataxia, or cerebellar signs.
• Associated signs and symptoms may suggest a cardiovascular etiology, such as chest pain, arrhythmia, dyspnea, or orthostatic blood pressure changes.

In addition to a general physical exam and complete neurologic exam, specific components of the physical exam should include:

• Nystagmus:
  • Bidirectional nystagmus or spontaneous vertical or rotatory nystagmus is suspicious for a central cause
  • BPPV- fast component towards the affected side, fatigable 
  • Vestibular neuritis – fast component away from the affected side, suppressed by visual fixation  
• HINTS exam
  • The HINTS exam is a bedside test that can help distinguish between central and peripheral causes of vertigo and dizziness. Notably, it should only be performed on patients who are currently symptomatic (acutely vertiginous). It consists of 3 parts:
    • Head impulse: the patient should be able to maintain fixation with rapid movement of their head from side to side. Inability to do so (a positive test) is evidenced by horizontal nystagmus followed by a rapid corrective saccade.
    • Nystagmus: Direction-changing or untestable nystagmus is considered a positive test and should prompt a workup for a central etiology.
    • Test of skew: eyes are alternately covered. Upward deviation of the uncovered eye is a positive test and should prompt a workup for a central etiology.
• Gait and balance testing
  • A positive Rhomberg test, where the patient loses balance or falls when the eyes are closed, can be seen with bilateral vestibulopathy or somatosensory dysfunction. 
  • A wide-based gait is suggestive of cerebellar dysfunction
• Vital signs
  • Frank hypotension
  • Orthostatic hypotension (defined as blood pressure drop from sitting to standing:  systolic blood pressure decrease of 20 mm Hg or a diastolic blood pressure decrease of 10 mm Hg)
  • Delayed orthostatic hypotension (usually detected on tilt-table testing)

The history and physical examination are aimed at deciphering whether there is a central (neurologic) vs. peripheral (vestibular) cause for the dizziness and imbalance. Hallmarks of a central cause include a normal (negative) horizontal head impulse test, direction-changing nystagmus, and positive skew deviation on the HINTS exam. The TITRATE algorithm breaks down acute and episodic vestibular syndromes by timing and triggers to suggest a likely diagnosis.[6]

Within episodic vestibular syndromes, triggered vertigo with a positive Dix-Hallpike is classic for BPPV. When the Dix-Hallpike is negative, the presence of orthostatic vital signs leads to the diagnosis of orthostatic hypotension. A Dix-Hallpike with atypical nystagmus is worrisome for a central etiology and should prompt emergent imaging. When the onset of an episodic vestibular syndrome is spontaneous (versus triggered), the likely diagnoses are vestibular migraine and Meniere disease. It is important to assess for vascular risk factors such as hypertension, dyslipidemia, cerebrovascular or coronary artery disease, and hypothyroidism. The ABCD2 score is part of the TITRATE algorithm to identify features suggestive of brain ischemia.

Diagnostic criteria for BPPV:

• Episodes of vertigo or dizziness triggered by a change in position, typically lying down or rolling onto the side from a supine position
• Attacks last < 1 min
• The Dix-Hallpike test produces torsional and vertical nystagmus towards the affected ear after a few seconds.[7][8]

Diagnostic criteria for Meniere disease:

• Two or more episodes of spontaneous vertigo lasting 30 minutes to 12 hours
• Low- to medium-frequency sensorineural hearing loss
• Unilateral tinnitus, ear fullness, and hearing loss in the affected ear may fluctuate [9]

Diagnostic criteria for vestibular neuritis:

• Sudden onset of vertigo lasting at least 24 hours, often accompanied by oscillopsia, nausea, and a tendency to fall
• Absence of cochlear symptoms
• Absence of associated neurological symptoms and signs [10]

Diagnostic criteria for vestibular labyrinthitis:

• Vestibular neuritis plus hearing loss
• occurs commonly after a viral illness such as a URI or otitis media

Diagnostic criteria for vestibular migraine:

• Five or more episodes of vertigo or dizziness with nausea
• Symptoms of moderate-severe intensity lasting 5 minutes to 72 hours.
• At least 50% of the episodes should be accompanied by migraine features such as unilateral headache, photophobia, phonophobia, or aura.
• Current or previous history of migraine [11]

Diagnostic criteria for superior canal dehiscence:

• At least 1 of the following symptoms
  • Bone conduction hyperacusis
  • Sound or pressure-induced vertigo or oscillopsia (illusion of an unstable visual world) time-locked to the stimulus
  • Pulsatile tinnitus
  • Autophony (hearing one’s internal bodily sounds loudly) [12]
• At least 1 of the following signs or diagnostic tests
  • Nystagmus evoked by sound or by changes in the middle ear or intracranial pressure
  • Low-frequency negative bone conduction thresholds on pure tone audiometry
  • Low cervical Vestibular Evoked Myogenic Potential (VEMP) thresholds or high ocular VEMP amplitudes
• Evidence of dehiscence of the superior semicircular canal on temporal bone CT [12]

Diagnostic criteria for persistent postural-perceptual dizziness:

• Dizziness, vertigo, or unsteadiness are present for 15 out of 30 days for 3 or months.
• Symptoms last several hours, may wax and wane, and become worse as the day progresses
• Symptoms occur without provocation but are exacerbated by Upright posture, active or passive motion, and exposure to moving visual stimuli or complex visual patterns
• Symptoms cause significant functional impairment and distress [13]

Diagnostic criteria for bilateral vestibulopathy:

• Disequilibrium and oscillopsia when walking or standing worsened in darkness or on uneven ground
• Asymptomatic while sitting or lying down under static conditions
• Reduced or absent angular vestibulo-ocular reflex function bilaterally [14]

Diagnostic criteria for perilymphatic fistula:

• Loss of hearing (sensorineural), tinnitus, ear fullness, or dizziness following barotrauma that either
  • Associated with perilymph biomarker testing with high sensitivity and specificity or
  • Associated with the visualization of perilymph leakage in the middle ear, symptoms resolve after treatment of the leak [15]

Evaluation

A thorough history and physical exam guide a provider on the diagnostic workup for dizziness symptoms.[16] A provider should not rely on labwork or imaging to solely provide the diagnosis of the cause of dizziness in most cases. Instead, labwork and imaging should be used to confirm a clinical suspicion. Point of care glucose testing and an EKG should be performed on all dizzy and unbalanced patients. Hypoglycemia or arrhythmias can be deadly etiologies that, when recognized, can be intervened upon promptly.

If there is clinical concern for a central neurologic cause for symptoms, a patient should undergo a non-contrast head CT, CTAs of the head and neck, and an MRI of the head. Additionally, they may benefit from an Echocardiogram with bubble study and carotid Doppler ultrasounds to complete a stroke workup. An Echocardiogram is also of great value when evaluating a cardiovascular etiology. Often a patient may require very specialized testing and imaging when the history and physical exam directs the healthcare provider towards a specific diagnosis (ie, superior canal dehiscence and high-resolution temporal bone CT imaging; vestibular neuritis and gadolinium contrast MRI).

Treatment / Management

Treatment is targeted at the underlying source of the patient's symptoms.

• Benign Paroxysmal Positional Vertigo may be treated with medications (such as meclizine), the Epley maneuver, or vestibular rehabilitation.[1] 
• Meniere disease is typically treated with diuretics and salt restriction. An otolaryngologist may treat Severe cases with intratympanic dexamethasone or gentamicin or endolymphatic sac surgery.[1]
• Vestibular neuritis can be treated with supportive care with antiemetics and vestibular suppressants such as antihistamines, benzodiazepines, or dopamine antagonists. It can also be treated with vestibular rehabilitation or possibly with steroids.[17]
• Vestibular migraines are often managed with reassurance and lifestyle modifications; however, at times, prophylactic medications are required, such as metoprolol, amitriptyline, topiramate, valproic acid, or flunarizine.[18]
• Superior canal dehiscence requires surgical intervention. 
• Idiopathic Perilymphatic fistulas are treated conservatively by avoiding activities that increase inner ear and intracranial pressure. PLFs with a known cause are treated surgically.[15]
• Orthostatic Hypotension can be improved by increasing water intake, reviewing the medication list, making lifestyle changes, and, in some cases, adding Midodrine or a mineralocorticoid to the patient's medication regimen.
(B3)

Differential Diagnosis

As discussed previously, the differential for dizziness is broad, given its varied sensations and causes. If a patient is experiencing presyncope or lightheadedness, this may point to a cardiac or autonomic etiology. Orthostatic Hypotension is diagnosed when a patient's systolic blood pressure drops by at least 20 mmHg or the diastolic blood pressure drops by at least 10 mmHg upon standing from a sitting or supine position. This can result in decreased cerebral perfusion, which causes dizziness symptoms. In addition to the organic causes discussed already, there are multiple nonorganic causes of dizziness. One of the most frequent is medication-induced dizziness. While they cannot all be listed and discussed here, a provider should be aware of the common classes, including antihypertensives, antibiotics, diuretics, NSAIDs, antiepileptics, and antidepressants.[19]

Prognosis

The prognosis of dizziness depends entirely on the underlying cause and its successful diagnosis. Peripheral causes of dizziness carry a better prognosis overall. Central and cardiac causes are known to increase morbidity and mortality, especially in older patients.[20]

Complications

The most considerable complication of dizziness is secondary injury. Dizziness and difficulty with balance are closely linked with a greater risk of falls.[21] Unfortunately, older individuals more commonly suffer from dizziness, and older individuals are also more likely to suffer severe injuries from falls. A single fall can result in a disabling injury that can forever change an individual's life. Dizziness may also impair their ability to function independently and perform their activities of daily living.