Field-testing of the ICHD-3 beta diagnostic criteria for classical trigeminal neuralgia

Introduction We aimed to field-test the beta version of the third edition of the International Classification of Headache Disorders (ICHD-3 beta) diagnostic criteria for classical trigeminal neuralgia (TN). The proposed beta draft of the 11th version of the International Classification of Diseases (ICD-11 beta) is almost exclusively based on the ICHD-3 beta classification structure although slightly abbreviated. We compared sensitivity and specificity to ICHD-2 criteria, and evaluated the needs for revision. Methods Clinical characteristics were systematically and prospectively collected from 206 consecutive TN patients and from 37 consecutive patients with persistent idiopathic facial pain in a cross-sectional study design.Results: The specificity of ICHD-3 beta was similar to ICHD-2 (97.3% vs. 89.2%, p=0.248) and the sensitivity was unchanged (76.2% vs. 74.3%, p=0.134). The majority of false-negative diagnoses in TN patients were due to sensory abnormalities at clinical examination. With a proposed modified version of ICHD-3 beta it was possible to increase sensitivity to 96.1% (p<0.001 compared to ICHD-3 beta) while maintaining specificity at 83.8% (p=0.074 compared to ICHD-3 beta). Conclusion ICHD-3 beta was not significantly different from ICHD-2 and both lacked sensitivity. A modification of the criteria improved the sensitivity greatly and is proposed for inclusion in the forthcoming ICHD-3.