II. Findings: Suggestive of central causes

  1. Nystagmus
    1. Vertical or torsional Nystagmus (pure Horizontal Nystagmus may occur with either peripheral or central cause)
    2. No Nystagmus on Horizontal Head Impulse Test
    3. Persists <6 seconds after Dix-Hallpike Maneuver
    4. Fixation of eyes on object does not inhibit Nystagmus
    5. Requires weeks to months to resolve
  2. Episodes last hours to days
  3. Severe imbalance impairs standing and walking
  4. No Hearing Loss or Tinnitus in most central cases
  5. Acute Vestibular Syndrome (Posterior Circulation in 25% of cases)
    1. Rapid onset (<1 hour) of acute, persistent, continuous Vertigo or Dizziness
    2. Associated with Nystagmus, Nausea or Vomiting, head motion intolerance, and gait unsteadiness
  6. Positive HiNTs Exam Criteria (at least 1 of 3 positive) are suggestive of Cerebellar CVA or Brainstem CVA (100% sensitive, 96% specific)
    1. Normal Horizontal Head Impulse Test (no saccade/correction on head rotation) OR
    2. Nystagmus that changes direction (or Vertical Nystagmus or torsional Nystagmus) OR
    3. Skew Deviation on Alternate Eye Cover Test in which uncovered eye demonstrates quick vertical gaze corrections
  7. Risk Factors
    1. Cardiovascular Risk Factors (e.g. Diabetes Mellitus, Hypertension, Hyperlipidemia)
    2. Atrial Fibrillation

III. Causes: Central Vertigo

  1. Non-Vascular Central Causes of Vertigo (CN 8 or CNS)
    1. Tumor
      1. Acoustic Neuroma (Vestibular Schwannoma)
      2. Infratentorial ependymoma
      3. Brainstem glioma
      4. Medulloblastoma
      5. Neurofibromatosis
    2. Migraine Headache
    3. Multiple Sclerosis
    4. Degenerative Ataxia Disorders or Cerebellar Syndromes
      1. See Ataxia
      2. Multiple System Atrophy
      3. Friedreich's Ataxia
      4. Parkinsonism-Plus Syndrome (PPS, Atypical Parkinsonism)
  2. Vascular disease related transient cerebral anoxia or CVA
    1. Dizziness Causes not vertebrobasilar specific
      1. Postural Hypotension
      2. Syncope
    2. Specific anoxia to vertebrobasilar system
      1. Vessel specific
        1. Brainstem Infarct (associated with Hearing Loss)
          1. Anterior Inferior Cerebellar Artery Infarction
          2. Anterior Vestibular Artery Infarction
        2. Brainstem Infarct (no Hearing Loss)
          1. Posterior Inferior Cerebellar Artery infarction
          2. Labyrinthine Artery Infarction
      2. Precipitating conditions
        1. Arteriosclerosis
        2. Hypertension
        3. Anemia
        4. Atrial Fibrillation

IV. Imaging

  1. MRI Brain (preferred)
    1. Consider repeating MRI at 3-7 days if posterior CVA is suspected but negative on initial MRI
    2. Initial MRI in first 48 hours misses 15% of posterior strokes
  2. CT Head
    1. Cannot reliably exclude posterior CVA (high False Negative Rate)

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