Diagnostic accuracy of warm and cold monothermal air caloric screening for bithermal canal paresis and derivation of a warm-test triage rule: a retrospective temporal validation study
- 1Xinhua Hospital, Shanghai Jiao Tong University School of Medicine
Abstract
Objective: To evaluate the diagnostic performance of bilateral warm (50 °C) and bilateral cold (24 °C) monothermal air caloric testing for detecting abnormal canal paresis (CP) defined by complete bithermal caloric testing, and to derive a low-risk warm-test triage rule.
Methods: The primary analysis included 7,753 patients who completed all four caloric irrigations, including 5,437 in the derivation cohort and 2,316 in the temporal validation cohort. Absolute CP ≥ 25%, calculated from the peak slow-phase velocities (SPVs) of all four irrigations using a uniform formula, served as the primary reference standard. In the derivation cohort, 200 predefined combinations of warm monothermal caloric asymmetry (MCA), the lower of the two warm SPVs (WarmMin), and spontaneous nystagmus SPV were evaluated, with sensitivity ≥97.5% as the primary constraint. The selected rule was then applied unchanged to the temporal validation cohort.
Results: Among 2,316 patients in the validation cohort, 846 (36.5%) had CP ≥ 25%. The AUC was 0.888 (95% CI, 0.873–0.902) for warm monothermal testing and 0.777 (95% CI, 0.756–0.798) for cold monothermal testing (AUC difference, 0.111; 95% CI, 0.084–0.136; DeLong p < 0.001). Of the 200 candidate rules, 99 achieved sensitivity ≥97.5%. The final candidate rule required |MCA_W| < 17.5%, WarmMin >11 °/s, and spontaneous nystagmus SPV < 4 °/s. In the validation cohort, this rule yielded a sensitivity of 98.3% (95% CI, 97.2–99.1%), specificity of 36.3% (95% CI, 33.8–38.8%), and negative predictive value of 97.4% (95% CI, 95.7–98.6%). Overall, 547 patients (23.6%) met the candidate-stop criteria, including 14 false negatives with CP ≥ 25%. Per 1,000 patients, the rule was estimated to avoid 472.4 subsequent cold irrigations while missing 6.0 cases with CP ≥ 25%. No false negatives with CP ≥ 40% were observed.
Conclusion: Warm monothermal testing showed better overall discrimination than cold monothermal testing. A composite rule incorporating MCA, minimum warm response strength, and spontaneous nystagmus SPV identified a subset of low-risk patients, but still produced a small number of CP-positive false negatives. The rule should not replace complete bithermal testing and requires independent prospective validation.
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BibTeX
@article{ma2026diagnostic,
title = {{Diagnostic accuracy of warm and cold monothermal air caloric screening for bithermal canal paresis and derivation of a warm-test triage rule: a retrospective temporal validation study}},
author = {Xiaobao Ma and Jiali Shen and Qin Zhang and Lu Wang and Wei Wang and Yulian Jin and Jun Yang and Jianyong Chen},
journal = {Frontiers in Neurology},
year = {2026},
month = oct,
doi = {10.3389/fneur.2026.1953594},
url = {https://www.frontiersin.org/articles/10.3389/fneur.2026.1953594/full},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Diagnostic accuracy of warm and cold monothermal air caloric screening for bithermal canal paresis and derivation of a warm-test triage rule: a retrospective temporal validation study
AU - Xiaobao Ma
AU - Jiali Shen
AU - Qin Zhang
AU - Lu Wang
AU - Wei Wang
AU - Yulian Jin
AU - Jun Yang
AU - Jianyong Chen
PY - 2026
DA - 2026/10/14
JO - Frontiers in Neurology
DO - 10.3389/fneur.2026.1953594
UR - https://www.frontiersin.org/articles/10.3389/fneur.2026.1953594/full
AB - Objective: To evaluate the diagnostic performance of bilateral warm (50 °C) and bilateral cold (24 °C) monothermal air caloric testing for detecting abnormal canal paresis (CP) defined by complete bithermal caloric testing, and to derive a low-risk warm-test triage rule. Methods: The primary analysis included 7,753 patients who completed all four caloric irrigations, including 5,437 in the derivation cohort and 2,316 in the temporal validation cohort. Absolute CP ≥ 25%, calculated from the peak slow-phase velocities (SPVs) of all four irrigations using a uniform formula, served as the primary reference standard. In the derivation cohort, 200 predefined combinations of warm monothermal caloric asymmetry (MCA), the lower of the two warm SPVs (WarmMin), and spontaneous nystagmus SPV were evaluated, with sensitivity ≥97.5% as the primary constraint. The selected rule was then applied unchanged to the temporal validation cohort. Results: Among 2,316 patients in the validation cohort, 846 (36.5%) had CP ≥ 25%. The AUC was 0.888 (95% CI, 0.873–0.902) for warm monothermal testing and 0.777 (95% CI, 0.756–0.798) for cold monothermal testing (AUC difference, 0.111; 95% CI, 0.084–0.136; DeLong p < 0.001). Of the 200 candidate rules, 99 achieved sensitivity ≥97.5%. The final candidate rule required |MCA_W| < 17.5%, WarmMin >11 °/s, and spontaneous nystagmus SPV < 4 °/s. In the validation cohort, this rule yielded a sensitivity of 98.3% (95% CI, 97.2–99.1%), specificity of 36.3% (95% CI, 33.8–38.8%), and negative predictive value of 97.4% (95% CI, 95.7–98.6%). Overall, 547 patients (23.6%) met the candidate-stop criteria, including 14 false negatives with CP ≥ 25%. Per 1,000 patients, the rule was estimated to avoid 472.4 subsequent cold irrigations while missing 6.0 cases with CP ≥ 25%. No false negatives with CP ≥ 40% were observed. Conclusion: Warm monothermal testing showed better overall discrimination than cold monothermal testing. A composite rule incorporating MCA, minimum warm response strength, and spontaneous nystagmus SPV identified a subset of low-risk patients, but still produced a small number of CP-positive false negatives. The rule should not replace complete bithermal testing and requires independent prospective validation.
SN - 1664-2295
ER -