Positional nystagmus as a factor for decision between peripheral- and central- nervous vestibular dysfunction

Introduction 

The examination of pathological eye movements in various body positions has a long tradition in neurotological diagnostics and was part of the assessment in vestibular schwannomas and central nervous vestibular dysfunction. The emergence of three-dimensional positioning chairs (TRV) and video-oculographic techniques allow more precise quantitative analysis of positional nystagmus responses.

Patients and methods 

In this retrospective study 100 patients with position-depending vertigo underwent an examination on the TRV chair. Neurotometric analysis was performed by viewing the infrared video-oculographic recordings simultaneously with the videographic observation of the body position relative to the gravity vector. Positional nystagmus was considered when it lasted at least 60 seconds in each position, whose direction could not be assigned to a stimulated semi-circular canal and which occurred without or with a short latency (<5 seconds). Statistical analysis of the results was performed using the program SPSS 27.0.1.0.

Results 

31 patients (31%) had positional nystagmus during TRV positioningPositional nystagmus was detected in 17 of 71 patients (24%) with a peripheral-vestibular cause of vertigo, in 7 of 9 patients (78%) with a peripheral and central cause of vertigo and in 7 of 20 patients (35%) with an other or unclear cause of vertigo. Positional nystagmus occured statistically significantly in patients who have central nervous vestibular disorders.

Conclusion 

In addition to other procedures such as the H.I.N.T.S., positional vestibular responses may help to select patients early and appropriately. However, further research, possibly with a prospective design, are needed to implement this clinical sign.

Conflict of Interest

The author declares that there is no conflict of interest.

Publication History

Article published online:
24 May 2022