Evaluation of Childhood Nystagmus

  • Less than 20% of childhood nystagmus is acquired
    • Urgent conditions 19%
    • Brain tumors 8.3%

Common Causes

  • Migraine/vestibular migraine — 26%
    • often accompanied by headache and vertigo.
    • Spontaneous nystagmus in adolescents with vestibular migraine tends to be variable in form
  • Peripheral vestibular disorders 14%
    • Vestibular neuritis and BPPV
      • characterized by unidirectional horizontal-torsional nystagmus
      • positive head impulse test
      • suppression with visual fixation.
    • Medication/substance-induced
      • Anticonvulsants (phenytoin, carbamazepine)
      • Sedatives
      • Dextromethorphan- most common drug reported to poison control centers.
      • Alcohol/illicit substances

Serious Causes

  • Intracranial tumors
    • Posterior fossa tumors (medulloblastoma, ependymoma, cerebellar astrocytoma)
      • Vertical nystagmus (downbeat or upbeat) is particularly suggestive
    • Anterior optic pathway tumors (optic nerve glioma)
  • Demyelinating disease (multiple sclerosis)
    • Can present as an acute vestibular syndrome in adolescents.
    • Central oculomotor signs (direction-changing nystagmus, normal head impulse test, skew deviation) help distinguish it from peripheral causes.
  • Posterior circulation stroke/hemorrhage
    • Rare in children but possible with underlying vascular anomalies, coagulopathy, or cardiac disease.
    • Cerebellar stroke can closely mimic vestibular neuritis.
  • Infectious/inflammatory encephalitis
    • Brainstem or cerebellar encephalitis (viral, autoimmune/paraneoplastic)

Other Important Causes

  • Chiari malformation —
    • Found in 3.4% of children undergoing MRI for nystagmus
    • typically causes downbeat nystagmus.
  • Metabolic diseases
    • Leukodystrophies
    • mitochondrial disorders
    • vitamin deficiencies (B12, thiamine)
  • Hereditary/degenerative cerebellar ataxias
    • Episodic ataxia type 2
    • spinocerebellar ataxias
  • Late-recognized congenital nystagmus — Occasionally, infantile nystagmus is not identified until adolescence; key distinguishing features include absence of oscillopsia and absent optokinetic nystagmus.[2]

Work Up

  • Targeted history:
    • Medication/substance exposure
    • headache pattern
    • prior neurologic episodes
    • family history of neurologic disease
    • timeline of onset (acute vs. subacute vs. chronic).
  • Focused exam:
  • Initial testing
    • MRI brain and orbits with contrast
    • Visual electrophysiology if visual pathway pathology is suspected
    • Toxicology screen if substance exposure is a concern.
  • Red Flags Suggesting Urgent Pathology (urgent neuroimaging and neurology consultation)
    • Cranial nerve deficits
    • Ataxia
    • Oscillopsia
    • Dissociated (asymmetric) nystagmus
    • Papilledema
    • Afferent pupillary defect

Resources