Separating posterior-circulation stroke from vestibular neuritis with quantitative vestibular testing. Issue 8 (August 2020)

• Record Type: Journal Article
• Authors: Calic, Zeljka; Nham, Benjamin; Bradshaw, Andrew P.; Young, Allison S.; Bhaskar, Sonu; D'Souza, Mario; Anderson, Craig S.; Cappelen-Smith, Cecilia; Cordato, Dennis; Welgampola, Miriam S.
• Is Part Of: Clinical neurophysiology. Volume 131:Issue 8(2020:Aug.)
• Page Start: 2047
• Page End: 2055
• Publication Date: 2020-08
• Subjects: Acute vestibular syndrome -- Video head impulse test -- Vestibulo-ocular reflex -- Saccades -- Posterior circulation stroke -- Vestibular neuritis; Neurophysiology -- Periodicals; Electroencephalography -- Periodicals; Electromyography -- Periodicals; Neurology -- Periodicals; 612.8
• DOI: 10.1016/j.clinph.2020.04.173
• Languages: English
• ISSNs: 1388-2457

Abstract

Highlights: Video Head Impulse tests of the vestibulo-ocular reflex (VOR) provided the best separation of vestibular neuritis (VN) from posterior circulation stroke (PCS). Refixation saccade-analysis complemented VOR gain measures in differentiating VN from PCS. Ocular VEMP (oVEMP) asymmetry demonstrated low sensitivity but high specificity as a marker of VN. Abstract: Objective: To separate vestibular neuritis (VN) from posteriorcirculation stroke (PCS) using quantitative tests of canal and otolith function. Methods: Video Head-Impulse tests (vHIT) were used to assess all three semicircular canal pairs; vestibulo-ocular reflex (VOR) gain and saccade metrics were examined. Cervical and ocular-Vestibular-Evoked Myogenic Potentials (c- and oVEMP) and Subjective Visual Horizontal (SVH) were used to assess otolith function. Results: For controls (n = 40), PCS (n = 22), and VN (n = 22), mean horizontal-canal VOR-gains were 0.96 ± 0.1, 0.85 ± 0.3 and 0.40 ± 0.2, refixation-saccade prevalence was 71.9 ± 41, 90.7 ± 57, 209.2 ± 62 per 100 impulses and cumulative-saccade amplitudes were 0.9 ± 0.4°, 2.4 ± 2.2°, 8.0 ± 3.5°. Abnormality-rates for cVEMP, oVEMP and SVH were 38%, 9%, 72% for PCS, and 43%, 50%, 91% for VN. A gain ≤0.68, refixation-saccade prevalence of ≥135% and cumulative-saccade amplitudes ≥5.3° separated VN from PCS with sensitivities of 95.5%, 95.5%, and 81.8%, and specificities of 68.2%, 86.4% and 95.5%. VOR-gain and saccade prevalence when combined, separated VN from PCS with a sensitivity and specificity of 90.9%. Abnormal oVEMP asymmetry-ratios were of low sensitivity (50%) but high specificity (90.9%) for separating VN from PCS. Conclusion: vHIT provided the best separation of VN from PCS. VOR-gain, refixation-saccade prevalence and amplitude were effective discriminators of VN from PCS. Significance: vHIT and oVEMP could assist early identification of the aetiology of Acute Vestibular Syndrome in the Emergency Room.