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Hashemi Eye Care - Neuroscience Institute and Research Center

Nystagmus (Finding)

Involuntary, rhythmic eye movements that can be observed during examination. Can be normal or indicate vestibular, neurological, or eye conditions.

3 min read

Nystagmus is an involuntary, rhythmic oscillation of the eyes. When observed during examination, it provides important diagnostic information about the visual and neurological systems.

Key Takeaways

  • Rhythmic, involuntary eye movements
  • May be normal (physiologic) or pathologic
  • Pattern helps identify cause
  • Can indicate inner ear, brain, or eye problems
  • Detailed description important for diagnosis

Describing Nystagmus

Direction

  • Horizontal: Side-to-side
  • Vertical: Up and down
  • Torsional: Rotational
  • Mixed: Combination

Waveform

  • Jerk: Slow drift in one direction, fast correction
  • Pendular: Equal speed both directions

Named Direction

For jerk nystagmus, named by the fast phase:

  • "Right-beating nystagmus" = fast phase to the right

Types of Nystagmus

Physiologic Nystagmus

Normal responses:

  • Optokinetic: Watching repeated moving objects
  • End-point: At extreme lateral gaze (few beats)
  • Vestibulo-ocular: During head rotation

Pathologic Nystagmus

Indicates underlying condition—see Nystagmus (Condition) for detailed information.

Peripheral vestibular (inner ear):

  • Mixed horizontal-torsional
  • Unidirectional (same direction all gaze positions)
  • Suppressed by visual fixation
  • Associated with vertigo

Central (brain):

  • May be any direction
  • May change direction with gaze
  • Not suppressed by fixation
  • May have other neurological signs

Congenital/Infantile:

  • Present from early life
  • Typically horizontal
  • May have null point (position of least nystagmus)

Key Observations

Gaze-Evoked Nystagmus

  • Appears when looking to the side
  • May indicate cerebellar or brainstem problem
  • Or medication effect

Downbeat Nystagmus

  • Fast phase downward
  • Suggests craniocervical junction abnormality
  • Chiari malformation, for example

Upbeat Nystagmus

  • Fast phase upward
  • Brainstem or cerebellar lesion

Periodic Alternating

  • Direction reverses periodically
  • Usually central cause

See-Saw Nystagmus

  • One eye rises and intorts, other falls and extorts
  • Then reverses
  • Suggests parasellar lesion

Clinical Assessment

History Questions

  • When did it start?
  • Constant or intermittent?
  • Associated symptoms (vertigo, hearing loss)?
  • Medications?

Examination

  • Observe in primary gaze
  • Check all directions of gaze
  • Look with and without fixation (Frenzel goggles)
  • Head impulse test
  • Other neurological examination

When Nystagmus Is Concerning

Features suggesting serious cause:

  • New onset in adults
  • Vertical nystagmus
  • Direction-changing nystagmus
  • Associated neurological symptoms
  • Not suppressed by fixation
  • Associated with headache or vomiting

Further Evaluation

Depending on clinical picture:

For comprehensive information on nystagmus as a condition, including causes, treatment, and living with nystagmus, see Nystagmus (Condition).

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