Head Shake Test

The Head Shake Test is a critical tool for evaluating vestibular function, particularly in identifying unilateral peripheral vestibular weaknesses. It’s a test for nystagmus.

The vestibular system, integral to maintaining balance and spatial orientation, can be afflicted by a range of pathologies that disrupt its function. Traditional vestibular tests, while effective, may not always detect subtle abnormalities or unilateral vestibular deficits that manifest only under conditions of heightened stimulation. The HST addresses this diagnostic gap by evaluating the VOR’s response to brief, intense vestibular inputs, thus uncovering latent vestibular dysfunctions.

How to perform the Head Shake Test?

The patient is seated facing the examiner. The examiner flexes the patient’s head 20° to 30°. In this position, the examiner asks the patient to rotate the head from side to side 20 times with the eyes closed and then stop. The patient then looks straight ahead while the examiner observes the eyes for nystagmus, which is an involuntary, rhythmic eye movement.

The examiner can observes the patient’s eyes with an infrared video camera or Frenzel goggles to detect any nystagmus.

The presence of post-head shake nystagmus (PHSN) is indicative of a vestibular asymmetry. The direction of the nystagmus typically points towards the side of the healthier or more functional vestibular system. A key aspect in interpreting the Head Shake Test results is understanding that the nystagmus generated is a compensatory mechanism for the differential input received by the brain from the vestibular organs on either side.

Sensitivity & Specificity

In one study to determine the sensitivity and specificity of Head Shake Test in the detection of vestibular system abnormalities as reflected by results of electronystagmography and rotary chair testing, the results have suggested that the Head Shake Test has a 27% sensitivity and an 85% specificity.

References & More

1. Orthopedic Physical Assessment by David J. Magee, 7th Edition.
2. Katsarkas A, Smith H, Galiana H. Head-shaking nystagmus (HSN): the theoretical explanation and the experimental proof. Acta Otolaryngol. 2000 Mar;120(2):177-81. doi: 10.1080/000164800750000865. PMID: 11603767. Pibmed
3. Jacobson GP, Newman CW, Safadi I. Sensitivity and specificity of the head-shaking test for detecting vestibular system abnormalities. Ann Otol Rhinol Laryngol. 1990 Jul;99(7 Pt 1):539-42. doi: 10.1177/000348949009900708. PMID: 2195962. Pubmed