Understanding Nystagmus in a Real-Life Vestibular Assessment

In vestibular rehab, the ability to accurately interpret nystagmus can be really useful for your diagnosis and management.

Expert vestibular physio Vanessa Simpson explains exactly how she does this in her assessment of an 80-year-old woman presenting with a vague two-year history of dizziness. Her symptoms were most noticeable when rolling over or getting out of bed, and she reported daily episodes of brief unsteadiness. Understandably, she was fearful of falling, and had already experienced a history of falls.

While we may see multiple patients like this, the case highlights how complex vestibular physiotherapy can be, and how a deepened understanding of concepts like nystagmus can help you get the best outcomes for your patients. This blog breaks down some of the key characteristics of nystagmus that can help you in your assessment.

If you want to see exactly how an expert physio assesses and manages a patient with dizziness, watch Vanessa Simpson’s full Case Study HERE. With Case Studies you can step inside the mind of experts and apply their strategies to get better results with their patients. Learn more here.

What is nystagmus?

Nystagmus is an involuntary, rhythmic oscillation of the eyes, where they most commonly drift slowly in one direction, then quickly shift back in the opposite direction. Clinically, it’s usually described in the direction of the fast phase (as this is easier to spot).

It can be horizontal, vertical or torsional, and often causes dizziness for the patient. Importantly, the characteristics of nystagmus help physios distinguish between central and peripheral vestibular pathology, guiding whether referral is needed or whether a condition such as Benign Positional Paroxysmal Vertigo (BPPV) is more likely.

Screening and assessment

Vanessa completed a range of assessments to decipher whether the patient was dealing with a central or peripheral cause for her dizziness.

First, it was important to rule out Cervical Artery Dysfunction (CAD) as a cause, and for this she recommends using the International IFOMPT cervical framework (1). Following this, Vanessa conducted a comprehensive vestibular assessment, including an oculomotor assessment which involved the below tests and patient findings:

1. Range of motion: patient had full range in all quadrants with no diplopia.
2. Smooth pursuit: patient could follow object well, with no corrective saccades present.
3. Spontaneous and gaze holding nystagmus, see Vanessa explain this in the video from her Case Study below:

4. Vergence/accommodation: patient was able to follow object moving near to far with no signs/symptoms.
5. Saccades: patient’s eyes could look quickly from one object to another, no over-or-under-shooting.
6. Vestibulo-Ocular Reflex (VOR) cancellation: patient’s nervous system was able to suppress the VOR reflex, no saccadic eye movements present.
7. Head impulse test: patient’s eyes stayed fixed on target, indicating intact VOR (i.e., no indication of a central issue).

Collectively, these findings were positive as they increased confidence in a peripheral vestibular disorder, and positional testing became the next focus to determine whether the patient was experiencing BPPV. See Vanessa give you a quick refresher on the types of BPPV in this clip from her Case Study:

Using nystagmus to pinpoint the problem

On supine roll testing, the patient demonstrated nystagmus beating to both left and right sides, with prolonged duration. This suggested a horizontal canal involvement, more specifically cupulolithiasis (where otoconia are adhered to the cupula).

In canalithiasis – the most common BPPV classification – the otoconia are free-floating, meaning nystagmus is often latent, brief (<1 min) and fatigues. While cupulolithiasis presents with nystagmus which has no latency, is prolonged (>1 min), and often doesn’t cease until the patient is moved out of that position.

The patient’s presentation was consistent with cupulolithiasis, but Vanessa wanted to know which side was affected so she could direct management accordingly. Because the patient was presenting with both left and right beating nystagmus on the supine roll test, Vanessa opted to use the bow and lean test.

Bow and lean test

This test includes two components:
1) Bow (head pitched forward 90°): in cupulolithiasis, nystagmus beats toward the unaffected side.
2) Lean (head tilted back 45–60°): in cupulolithiasis, nystagmus beats toward the affected side.

Another useful sign of cupulolithiasis is the null point, when the head is turned ~20–30° toward the affected ear, nystagmus temporarily reduces or disappears. See what Vanessa saw in her real-life patient in the below video from her Case Study:

Wrapping up

There’s no doubt vestibular assessment can get really complex – that’s why it’s a whole speciality in itself!

But having a better understanding of nystagmus can go a long way in helping you differentiate central vs peripheral causes, as well as between different peripheral issues.

Ultimately, accurate identification of the problem canal and mechanism directs the most effective treatment approach, instills trust, and gives the patient the best chance of regaining their confidence and independence.

If you want to see exactly how expert vestibular physio Vanessa Simpson managed this patient from start to finish, watch her full Case Study HERE.