Ultrasound-Measured Vagus Nerve Size Linked to White Matter Lesions in Vascular Risk Patients

This study aimed to explore the association between vagus nerve (VN) size, as measured through ultrasonography, and the severity of white matter lesions (WMLs) in patients with vascular risk factors. Autonomic nervous system dysfunction, which can be indicated by changes in VN size, is believed to play a role in hypertension and its impact on the brain. Using carotid ultrasonography, the cross-sectional area (CSA) of the VN was assessed in 196 patients with a history of stroke and other comorbidities. Measurements of the common carotid artery’s intima-media thickness (IMT) and interadventitial diameter (IAD) were also taken. The severity of WMLs was evaluated using the Fazekas classification and Scheltens’ scale. Results revealed that the CSA of the right VN was significantly larger (2.08 ± 0.65 mm²) compared to the left VN (1.56 ± 0.44 mm²), and this difference was statistically significant (P < 0.001). Multiple regression analyses showed that older age, hypertension, larger right CCA IAD, and a smaller CSA of the right VN were independently associated with the severity of WMLs, as measured by Scheltens’ scale. Similarly, a smaller CSA of the left VN was also linked to more severe WMLs. These findings indicate that VN size may be related to the development of WMLs in patients with vascular risk factors, although a causal relationship cannot be confirmed. This study highlights the potential role of autonomic nervous system dysfunction in the progression of WMLs, offering a new avenue for understanding and managing these lesions in high-risk populations.