Bárány’s sign, also known as the caloric test, is defined as the elicitation of rotary nystagmus in response to warm or cold water irrigation of the external auditory canal.

• Warm water irrigation: Produces rotary nystagmus toward the irrigated ear.

• Cold water irrigation: Produces rotary nystagmus away from the irrigated ear.

• Absence of nystagmus suggests labyrinthine or vestibular dysfunction.

Pathophysiology

• Bárány’s sign evaluates the vestibulo-ocular reflex (VOR), which stabilizes gaze during head movement.

• Thermal stimulation of the endolymph in the semicircular canals causes convection currents, which deflect the cupula in the horizontal semicircular canal.

• The deflection induces afferent signals via the vestibular nerve to the brainstem, eliciting eye movements (nystagmus).

• Dysfunction in the labyrinth, vestibular nerve, or brainstem results in absent or abnormal responses.

Examination Technique

• Patient positioning: Supine with head elevated at 30 degrees.

• Irrigation procedure:

  1. Irrigate the external auditory canal with water at approximately 44°C (warm) and 30°C (cold).

  2. Observe eye movements for nystagmus direction and intensity.

• Interpretation:

  • Nystagmus toward the irrigated side indicates a normal response to warm water.

  • Nystagmus away from the irrigated side indicates a normal response to cold water.

  • No nystagmus suggests labyrinthine or vestibular pathology.

Clinical utility

• Assessment of vestibular function: Identifies unilateral or bilateral vestibular loss.

• Diagnostic tool for dizziness and vertigo: Differentiates peripheral vs central vestibular disorders.

• Preoperative evaluation: Assists in planning surgeries affecting the inner ear.

Differential Diagnosis

Management

• Vestibular rehabilitation: Exercises to improve balance and gaze stability.

• Treat underlying cause:

  • Vestibular neuritis: corticosteroids, antiemetics.

  • Meniere’s disease: dietary modifications, diuretics, intratympanic therapy.

• Monitor recovery: Repeated caloric testing may assess progress of vestibular function.

Pediatric considerations

• Test is less commonly performed in children due to discomfort and poor cooperation.

• Noninvasive alternatives (video head impulse test, rotary chair) may be preferred.

Geriatric considerations

• Elderly patients may have reduced caloric responses due to age-related vestibular decline.

• Important to differentiate normal aging changes from pathology.

Limitations

• Test may be uncomfortable or nauseating.

• Ear infection, tympanic membrane perforation, or external canal obstruction may interfere with results.

• Does not evaluate all semicircular canals; complementary tests may be needed.

Patient counseling

• Explain the purpose of the caloric test to assess balance and inner ear function.

• Warn about temporary dizziness or nausea during testing.

• Reassure that symptoms usually resolve quickly after the procedure.

Conclusion

Bárány’s sign is a classic vestibular assessment tool that evaluates labyrinthine function via the caloric test. Proper technique and interpretation help differentiate peripheral vs central vestibular disorders, guide treatment strategies, and prevent complications related to balance dysfunction.

References

1. Bárány R. Über die Bedeutung der Ohrperfusion bei der Diagnose vestibulärer Störungen. Acta Otolaryngol. 1906;3:333–351.

2. Hain TC. Vestibular testing. In: Cummings Otolaryngology – Head & Neck Surgery. 7th ed. Philadelphia, PA: Elsevier; 2020.

3. Buttaro TM, Tybulski J, Bailey PP, Sandberg-Cook J. Primary Care: A Collaborative Practice. St. Louis, MO: Mosby Elsevier; 2008.

4. McCance KL, Huether SE, Brashers VL, Rote NS. Pathophysiology: The Biologic Basis for Disease in Adults and Children. 8th ed. Maryland Heights, MO: Mosby Elsevier; 2019.

5. Herdman SJ, Clendaniel RA. Vestibular Rehabilitation. 4th ed. Philadelphia, PA: F.A. Davis; 2014.