Diagnostic accuracy of a smartphone bedside test to assess the fixation suppression of the vestibulo-ocular reflex: when nothing else matters.

ABSTRACT: OBJECTIVE:Validation of a bedside test to objectify the fixation suppression of the vestibulo-ocular reflex (FS-VOR) in patients with a cerebellar syndrome and healthy controls. METHODS:The vestibulo-ocular reflex and its fixation suppression were assessed by video-nystagmography (VNG) in 20 healthy subjects (mean age 56?±?15) and 19 patients with a cerebellar syndrome (mean age 70?±?11). The statistical cutoff delineating normal from pathological FS-VOR was determined at the 2.5th percentile of the normal distribution of the healthy cohort. VNG was then compared to a bedside test, where eye movements were recorded with a smartphone while patients were rotated on a swivel chair at a defined speed and amplitude. These videos were rated as normal or pathological FS-VOR by six blinded raters, and results compared to VNG. RESULTS:VNG in healthy controls showed FS-VOR with a reduction of nystagmus beats by 95.0%?±?7.2 (mean?±?SD). The statistical cutoff was set at 80.6%. Cerebellar patients reduced nystagmus beats by only 26.3%?±?25.1. Inter-rater agreement of the smartphone video ratings was 85%. The sensitivity of the video ratings to detect an impaired FS-VOR was 99%, its specificity 92%. Inter-test agreement was 91%. CONCLUSION:The smartphone bedside test is an easily performed, reliable, sensitive, specific, and inexpensive alternative for assessing FS-VOR.

SUBMITTER: Gandor F 

PROVIDER: S-EPMC7351825 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature