Vagus Somatosensory Evoked Potentials – A Possibility for Diagnostic Improvement in Patients with Mild Cognitive Impairment

Abstract

Objective: Vagus somatosensory evoked potentials (VSEP) are far-field potentials probably generated in nuclei of then. vagus in the lower brainstem. They represent a putative, easily applicable method for discrimination between patients with Alzheimer’s disease (AD), patients with mild cognitive impairment (MCI), and healthy controls (HC). Methods: Thirteen patients with AD, 12 with MCI, and 27 age- and gender-matched HC were investigated by stimulating the cutaneous branch of the n. vagus; 8, 6, and 20, respectively, were included in the main part of the analysis. Results: In fronto-central recordings (electrode positions Fz-F4) a grading from HC over MCI to AD could be found, with a significant linear trend over the three groups and significantly increased latencies of the cognitively impaired patients but no significant difference between MCI and AD. Conclusion: The results indicate that the method of VSEP is able to discriminate between cognitively declined patients and HC, whereas no clear-cut differences were detected between MCI and AD.

Assessment of Brainstem Function with Auricular Branch of Vagus Nerve Stimulation in Parkinson’s Disease

“…Because in the present study, the sensitivity to detect ABVN-SEP changes was enhanced by additional recording sites (established for recording of far field potentials such as AEPs), methodological factors are unlikely to explain this discrepancy. Prolonged latencies of ABVN-SEP have been described in previous studies in patients with AD compared to healthy controls [ 13 , 34 ], where degeneration of the vagal nuclei complex, possibly including parts processing somatosensory afferents, is present early in the disease course [ 14 ]. It, therefore, is conceivable that prolonged ABVN-SEP latencies found previously in PD patients [ 11 ] may reflect the co-presence of Alzheimer and PD pathology in these patients.…”

Moving beyond belief: A narrative review of potential biomarkers for transcutaneous vagus nerve stimulation

“…Furthermore, in people reporting to have experienced a worsening of their memory performance, only those who worried about this showed a prolonged P2 component (Hagen et al, 2015). In addition, no P1 differences could be observed when comparing people with Alzheimer's disease to healthy controls and people with mild cognitive impairments, possibly due to the heterogeneity in the Alzheimer's disease group (Metzger et al, 2012).…”

Auricular Acupuncture and Vagal Regulation

“…Far-field potentials from brainstem after transcutaneous vagus nerve stimulation at the auricle have been utilized as a noninvasive method in the early diagnosis of neurodegenerative disorders [31–33]. We suggest that further study is needed on whether auricular acupuncture plays a role in the prevention and treatment of these neurodegenerative disorders via activating the vagal nuclei in the brainstem.…”