Noninvasive Vagus Nerve Stimulation Reduces Brain Lesion Volume in a Rat model of Traumatic Brain Injury
Background: Traumatic brain injury (TBI) continues to be a major cause of death and disability. Vagus nerve stimulation (VNS) has been shown to reduce proinflammatory responses in TBI models. We assessed the effect of a non-invasive VNS (nVNS) on reducing the lesion volume in a rat model of TBI.
Methods: TBI was induced using a standard CCI (Impact one, Leica) model. Rats were randomized into three groups: TBI control, TBI treated with five 2-min nVNS stimulations, and TBI treated with five 2x2-min nVNS stimulations using the gammaCore device was initiated 30 minutes post-TBI (10 minutes interval between each stimulation). MRI studies were performed at 1 and 7 days post-TBI. Lesion volumes were calculated using Image J software.
Results: A significant effect on the lesion volume was visible for each treatment on days 1 and 8. For day 1, the overall difference of lesion volume (log10 transformed) among the treatment groups ‘Control’ (N=13), VNS-2min (N=13), and VNS-4min (N=14) was highly significant (Kruskal-Wallis test statistics: 23.85, 2DF. P<0.0001). For day 7, the overall difference of lesion volume was also highly significant (test statistics: 23.85, 2DF. P<0.0001). Lesion volumes effect sizes (Cohen’s d) were large: -1.09 (95%CI [-2.28 to -0.08]) for the VNS-2min group and very large: -2.49 ([-3.48 to -1.39]) for the VNS-4min group vs. control.
Conclusions: Both nVNS treatments (2min and 4min) were associated with a large lesion volume reduction compared to the control group. Moreover, VNS-4min stimulations lead to lesions with significantly smaller sizes compared to the VNS-2min.
Divani, Afshin A.; Erik Taylor; Hafiz Abdullha Ikram; Pascal Salazar; Yirong Yang; Karen SantaCruz; Onamma A. Edeh; and Denis E. Bragin. "Noninvasive Vagus Nerve Stimulation Reduces Brain Lesion Volume in a Rat model of Traumatic Brain Injury." (2022). https://digitalrepository.unm.edu/hsc-bbhrd/51
Poster presented at the Brain & Behavioral Health Research Day 2022