Vertigo

Background

• Perception of movement (rotational or otherwise) where no movement exists
• Pathophysiology
  • Mismatch or asymmetric activity of visual, vestibular, and/or proprioceptive systems
• Must distinguish peripheral from central cause
  • Peripheral: 8th CN, vestibular apparatus
  • Central: Brainstem, cerebellum

Clinical Presentation

Central vs. Peripheral Causes of Vertigo

	Peripheral	Central
Onset	Sudden	Sudden or slow
Severity	Intense spinning	Ill defined, less intense
Pattern	Paroxysmal, intermittent	Constant
Aggravated by position/movement	Yes	Variable
Nausea/diaphoresis	Frequent	Variable
Nystagmus	Horizontal and unidirectional	Vertical and/or multidirectional
Fatigue of symptoms/signs	Yes	No
Hearing loss/tinnitus	May occur	Does not occur
Abnormal tympanic membrane	May occur	Does not occur
CNS symptoms/signs	Absent	Usually present

Differential Diagnosis

Vertigo

• Vestibular/otologic
  • Benign paroxysmal positional vertigo (BPPV)
  • Traumatic (following head injury)
  • Infection
    • Labyrinthitis
    • Vestibular neuritis
    • Ramsay Hunt syndrome
  • Ménière's disease
  • Ear foreign body
  • Otic barotrauma
  • Otosclerosis
• Neurologic
  • Cerebellar stroke
  • Vertebrobasilar insufficiency
  • Lateral Wallenberg syndrome
  • Anterior inferior cerebellar artery syndrome
  • Neoplastic: cerebellopontine angle tumors
  • Basal ganglion diseases
  • Vertebral Artery Dissection
  • Multiple sclerosis
  • Infections: neurosyphilis, tuberculosis
  • Epilepsy
  • Migraine (basilar)
• Other
  • Hematologic: anemia, polycythemia, hyperviscosity syndrome
  • Toxic
    • Alcohol
    • Aminoglycosides
  • Chronic renal failure
  • Metabolic
    • Thyroid Disease
    • Hypoglycemia

Diagnosis

Work-up

Diagnostic algorithm Vertigo

1. Glucose check
2. Full neuro exam
3. TM exam
4. CTA or MRA (diagnostic study of choice) of the neck/brain if symptoms consistent with central cause

Test	Sensitivity
HINTS	100%
MRI (24hrs)	68.40%
MRI (48hrs)	81%
CT non con	26%

HINTS Exam

Proposed as method of distinguishing peripheral cause from cerebellar/brain stem CVA in the Emergency Department population

Inclusion Criteria

• HINTS exam should only be used in patient with acute persistent vertigo, nystagmus, and a normal neurological exam.
• HINTS exam, when done correctly, has high sensitivity and specificity in distinguishing peripheral vs central etiologies of vertigo
• Note that the original study was done by neuro-ophthalmologists in a differentiated patient base. This exam has not been studied in a large ED population yet

The 3 components of the HINTS exam include:

HINTS Test	Reassuring Finding
Head Impulse Test	Abnormal (corrective saccade)
Nystagmus	Unidirectional, horizontal
Test of Skew	No skew deviation

• Always use correct terminology; "HINTS negative" does not convey a clear interpretation. State "HINTS central" or "HINTS peripheral" as suggested in literature
  • If able, specify the exact exam finding as shown by chart above

Head Impulse Test

Test of vestibulo-ocular reflex function

1. Have patient fix their eyes on your nose
2. Move their head rapidly in the horizontal plane to the left and right
   • When the head is turned towards the normal side, the vestibular ocular reflex remains intact and eyes continue to fixate on the visual target
   • When the head is turned towards the affected side, the vestibular ocular reflex fails and the eyes make a visible corrective saccade to re-fixate on the visual target
   • Normally, a functional vestibular system will identify any movement of the head position and instantaneously correct eye movement accordingly so that the center of the vision remains on a target.
     • This reflex fails in peripheral causes of vertigo affecting the vestibulocochlear nerve unilaterally; thus, failure of the reflex unilaterally is reassuring (since the cause is peripheral)
   • Note that in central causes of vertigo, test may show normal reflex response OR failure of the reflex BILATERALLY

Nystagmus

1. Observation for nystagmus in primary, right, and left gaze
   • No nystagmus (normal) or only horizontal unilateral nystagmus (fast direction only in one direction) is reassuring
   • Any other type of nystagmus is abnormal, including vertical or bidirectional nystagmus

Test of Skew

1. Have patient look at your nose with their eyes and then cover one eye
2. Then rapidly uncover the eye and quickly look to see if the eye moves to re-align.
3. Repeat with on each eye
   • Skew deviation is a fairly specific predictor of brainstem involvement in patients with acute vestibular syndrome. The presence of skew may help identify stroke when a positive head impulse test falsely suggests a peripheral lesion.
   • Skew is also known vertical dysconjugate gaze and is a sign of a central lesion

• A positive HINTS exam: 100% sensitive and 96% specific for the presence of a central lesion.
• The HINTS exam was more sensitive than general neurological signs: 100% versus 51%.
• The sensitivity of early MRI with DWI for lateral medullary or pontine stroke was lower than that of the HINTS examination (72% versus 100%, P=0.004) with comparable specificity (100% versus 96%, P=1.0).

• If any of the above 3 tests are consistent w/ CVA obtain full work-up (including MRI)

Management

Peripheral

Symptomatic control

1. Antihistamines: inhibit vestibular stimulation and vestibular-cerebellar pathways
   • Meclizine (antivert) 25mg PO QID
   • Diphenhydramine (Benadryl) 25-50mg IM, IV, or PO q4hr
2. Anticholinergics
   • Scopolamine transdermal patch 0.5mg (behind ear) QID
3. Antidopaminergics
   • Metoclopramide 10-20 IV or PO TID

Cause Reversal

1. Epley maneuver (see BPPV)

Central

• R/O CVA
• MRI
• R/O Vascular insufficiency

Disposition

• Most patients with peripheral vertigo can be discharged home
• All patients with central vertigo require urgent imaging and consultation while in the ED

See Also

• Dizziness
• EBQ:HINTS_Exam
• Cerebellar Stroke
• Stroke syndromes