Does a vestibular migraine present with nystagmus at rest?

Vestibular Migraine and Nystagmus

Vestibular migraine typically does not present with nystagmus at rest, but rather shows nystagmus during positional testing or during acute attacks. 1, 2

Characteristics of Nystagmus in Vestibular Migraine

Nystagmus Patterns

• Spontaneous nystagmus is observed in approximately 71% of patients during attacks (ictal), but only in about 15% between attacks (interictal) 3
• When present during attacks, spontaneous nystagmus characteristics include:
  • Horizontal direction in 49.5% of cases
  • Vertical direction in 21.8% of cases
  • Low velocity (mean 5.3°/s) 3
• Positional nystagmus is more common, found in:
  • 25.8% of patients during attacks
  • 55.4% of patients between attacks 3

Key Diagnostic Features

• Positional nystagmus in vestibular migraine is typically:
  • Sustained (non-fatigable)
  • Low velocity
  • Can be horizontal, vertical, or torsional
  • Visible when fixation is blocked 2
  • No latency period before onset 4
  • Markedly reduced by visual fixation 4

Differential Diagnosis Considerations

Central vs. Peripheral Causes

Nystagmus findings that suggest a central cause rather than peripheral vertigo include:

• Down-beating nystagmus on the Dix-Hallpike maneuver
• Direction-changing nystagmus occurring without changes in head position
• Baseline nystagmus without provocative maneuvers 1

Distinguishing Vestibular Migraine

• Vestibular migraine can be distinguished from BPPV by:
  • Necessary migraine/headache components (though not always present)
  • Nystagmus that doesn't fatigue with repeated positioning
  • Possible vertical nystagmus (up-beating or down-beating) during positional testing 1, 4
• Vestibular migraine differs from vertebrobasilar insufficiency:
  • Vertebrobasilar insufficiency nystagmus is typically gaze-evoked
  • Vertebrobasilar insufficiency nystagmus doesn't fatigue and isn't easily suppressed by gaze fixation 1

Clinical Implications

Diagnostic Approach

• The finding of low-velocity, sustained nystagmus with positional testing in a patient presenting with vertigo, nausea, and headache strongly suggests vestibular migraine 2
• This diagnosis is further supported when the nystagmus resolves when the patient is symptom-free 2
• Vestibular testing during symptom-free intervals is typically normal in vestibular migraine patients 2, 3

Treatment Response

• Prophylactic therapy for vestibular migraine (such as topiramate or cinnarizine) has been shown to resolve positional vertigo and nystagmus in over 90% of patients 4
• Antimigrainous medications appear effective for both acute attacks and prevention, though stronger evidence is needed 5

Important Pitfalls to Avoid

• Misdiagnosing vestibular migraine as BPPV due to positional vertigo symptoms
• Failing to recognize that vestibular migraine can present without headache (approximately one-third of patients have monosymptomatic attacks of vertigo without headache) 5
• Overlooking vestibular migraine in patients with dizziness (it accounts for approximately 10% of patients with vertigo and dizziness) 5
• Relying solely on the presence/absence of nystagmus at rest for diagnosis, rather than performing comprehensive positional testing

Remember that vestibular migraine has a variable clinical presentation and is considered a "chameleon" among episodic vertigo syndromes 5. The presence of nystagmus during attacks that resolves between episodes is a valuable diagnostic clue.