Abstract
Objectives: We aimed to investigate the diagnostic accuracy of Caloric
Testing and video Head Impulse Testing (vHIT) in differentiating between
vestibular neuritis and strokes in acute dizziness. Design: Prospective
cross-sectional study. Setting: Emergency department of a tertiary
referral center. Participants: 1677 adult patients were screened between
2015 and 2020 for AVS, of which 152 met the inclusion criteria.
Inclusion criteria consisted of a state of continuous dizziness,
associated with nausea or vomiting, head-motion intolerance, new gait or
balance disturbance and nystagmus. Patients were excluded if symptoms
lasted <24 hours or if the index ED visit was >72
hours after symptom onset. Eighty-five patients completed testing of
which 58 were vestibular neuritis and 27 strokes. Main outcome measures:
All patients underwent calorics and vHIT followed by a delayed MRI (gold
standard for vestibular stroke confirmation). Results: The
sensitivity/specificity for detecting stroke (caloric asymmetry cut-off
of 30.9%) was 75% and 86.8% respectively (Negative likelihood ratio
(NLR) 0.29) compared to 91.7% and 88.7% for vHIT (NLR 0.094). Best VOR
gain cut-off was 0.685. Twenty-five percent of vestibular strokes were
misclassified by calorics, 8% by vHIT. Conclusions: Caloric testing
demonstrated lower accuracy than vHIT in discriminating stroke from
vestibular neuritis in acute dizziness. Asymmetric caloric responses can
also occur with vestibular strokes and might put the patient at risk for
misdiagnosis. We therefore recommend replacing calorics with vHIT in the
acute setting. Caloric testing has still its place as a diagnostic tool
in an outpatient setting.