Related Experiment Video
Updated: Nov 8, 2025
A Multimodal Imaging- and Stimulation-based Method of Evaluating Connectivity-related Brain Excitability in Patients with Epilepsy
Published on: November 13, 2016
SPECT imaging of cerebral blood flow changes induced by acute trigeminal nerve stimulation in drug-resistant
Beniamina Mercante1, Susanna Nuvoli2, Maria A Sotgiu1
1Department of Biomedical Sciences, University of Sassari, Sassari, Italy.
Objective:
To explore the cortical areas targeted by acute transcutaneous trigeminal nerve stimulation (TNS) in patients with drug-resistant epilepsy (DRE) using single photon emission computed tomography (SPECT).
Methods:
Ten patients with DRE underwent brain SPECT at baseline and immediately after a 20-minute TNS (0.25 ms; 120 Hz; 30 s ON and 30 s OFF) applied bilaterally to the infraorbital nerve. The French Color Standard International Scale was used for qualitative analyses and z-scores were used to calculate the Odds Ratio (OR).
Results:
At baseline global hypoperfusion (mainly in temporo-mesial, temporo-parietal and fronto-temporal and temporo-occipital areas) was detected in all patients. Following TNS, a global increase in cortical tracer uptake and a significant decrease in median hypoperfusion score were observed. A significant effect favoring a general TNS-induced increase in cortical perfusion (OR = 4.96; p = 0.0005) was detected in 70% of cases, with significant effects in the limbic (p = 0.003) and temporal (p = 0.003) lobes. Quantitative analyses of z-scores confirmed significant TNS-induced increases in perfusion in the temporal (+0.59 SDs; p = 0.001), and limbic (+0.43 SDs; p = 0.03) lobes.
Conclusion:
Short-term TNS is followed a global increase in cortical perfusion, namely in the temporal and limbic lobes.
Significance:
The TNS-induced perfusion increase may reflect neurons' activity changes in cortical areas implicated in the epilepsy network.
