Ototoxic Vestibulo-ocular Dysfunction Syndrome

    • Impairment of the vestibulo-ocular reflex caused by bilateral toxicity to the vestibular organs in the inner ears
    • Common cause: intravenous aminoglycoside treatment
    • Core clinical features
      • Blurred vision provoked by head or body movement
      • Viewed objects appear to jiggle (“oscillopsia”)
      • Saccades and pursuit are normal and there is no nystagmus
      • Visual acuity is reduced by head oscillation (abnormal “dynamic visual acuity test”)
      • Abrupt shift of the head evokes contraversive saccades (abnormal “head impulse test”)
    • Possible accompanying neurologic or otologic features
      • Imbalance on uneven surfaces and in darkness
      • Hearing loss in both ears
      • Abnormal caloric irrigation and chair rotation tests disclose an impaired vestibulo-ocular reflex
    • Imaging features
      • No abnormalities
    • Psychogenic symptoms
    • Suspect this condition especially in patients treated with intravenous aminoglycosides—even if medication doses were “appropriate”
    • Order formal vestibular function testing if history, dynamic visual acuity, and head impulse tests suggest vestibulo-ocular reflex failure
    • Tip: diagnosis is often delayed because the patient does not express symptoms clearly and because the standard ophthalmic examination does not include the dynamic visual acuity and head impulse tests
    • Deficit persists, but patients adapt by minimizing rapid head and body movements, avoiding uneven surfaces, and being cautious when walking in darkness
    • Monitoring with the dynamic visual acuity or head impulse tests during aminoglycoside administration and avoidance of high aminoglycoside blood trough levels might reduce the likelihood of this debilitating condition

    Brainstem Ocular Motor Disorders

    Internuclear Ophthalmoplegia Skew Deviation Dorsal Midbrain Syndrome Thalamic or Tegmental Midbrain Syndrome Unilateral Pontine Syndrome Bilateral Pontine Syndrome Dorsolateral Medullary (Wallenberg) Syndrome Ototoxic Vestibulo-ocular Dysfunction Syndrome Acute Upgaze Deviation Acute Downgaze Deviation Acute Comitant Esotropia Omnidirectional Slow Saccades Omnidirectional Saccadic Pursuit