Abstract
BACKGROUND: Ultrasound (US) measurement of the optic nerve sheath diameter serves as a valuable adjunctive monitoring tool in acute care. However, the relationship between optic nerve stiffness assessed by shear wave elastography (SWE) and the presence of ipsilateral brain or eye lesions in patients with secondary headaches remains unclear. The aim of this study was to explore the association between optic nerve stiffness values and the presence of ipsilateral brain or eye lesions in patients with secondary headaches. METHODS: From January 2023 to April 2024, a retrospective study was conducted on 54 patients presenting with secondary headaches. Optic nerve sheath diameter and stiffness values were measured using grey-scale and SWE US, respectively. Optic nerves were categorized into 2 groups based on the presence or absence of ipsilateral brain or eye lesions: the target group (with ipsilateral lesions) and the contralateral group (without ipsilateral lesions). Comparisons of ultrasonographic parameters between these groups were performed. RESULTS: A total of 18 patients (mean age: 52.28±11.78 years, 11 females; 36 optic nerves) participated in the study. No significant difference in optic nerve sheath diameter was observed between the two groups (P=0.353). In contrast, optic nerve stiffness measured by SWE was significantly higher in the target group compared to the contralateral group (P<0.001). The area under the receiver operating characteristic (ROC) curve (AUC) for SWE stiffness in predicting ipsilateral lesions was 0.861 [95% confidence interval (CI): 0.653-0.986, P<0.0001]. The application of an SWE stiffness threshold of 59.2 kPa for localizing ipsilateral lesions yielded a sensitivity of 88.89% (95% CI: 65.3-98.6%) and a specificity of 72.22% (95% CI: 46.5-90.3%). CONCLUSIONS: Increased optic nerve stiffness correlates with the presence of ipsilateral brain or eye lesions in patients with secondary headaches. Optic nerve elastography can aid in localizing lesions in the brain or eye in patients with secondary headaches.