Transcutaneous auricular vagus nerve stimulation improves working memory in temporal lobe epilepsy: A randomized...

Area of Science:

• Neuroscience
• Epilepsy Research
• Cognitive Function

Background:

• Refractory temporal lobe epilepsy (rTLE) often presents with cognitive deficits, particularly in working memory (WM).
• Non-invasive neuromodulation techniques are being explored to improve cognitive function in neurological disorders.
• Transcutaneous auricular vagus nerve stimulation (taVNS) is a promising method for modulating neural activity.

Purpose of the Study:

• To investigate the impact of taVNS on WM performance in patients with rTLE.
• To explore the underlying neural mechanisms, specifically changes in brain oscillations, associated with taVNS in rTLE.
• To assess the efficacy of a 20-week taVNS protocol compared to a sham procedure.

Main Methods:

• A randomized, double-blind, sham-controlled study involving 28 rTLE patients.
• Patients received either active taVNS (a-taVNS) or sham taVNS (s-taVNS) for 20 weeks.
• Visual WM tasks were performed during stimulation, with simultaneous 19-channel electroencephalography (EEG) recording to analyze neural oscillations.

Main Results:

• Active taVNS significantly reduced reaction time in WM tasks compared to baseline (p=0.010), while sham stimulation showed no significant effect (p>0.05).
• A significant decrease in frontal midline theta band power spectral density (PSD) was observed during WM encoding, maintenance, and retrieval phases in the active taVNS group (p<0.05).
• No significant changes in theta PSD were found in the sham taVNS group.

Conclusions:

• taVNS effectively improved WM performance in rTLE patients.
• The observed alterations in frontal midline theta oscillations may serve as a neurophysiological marker for the cognitive regulatory effects of taVNS.
• taVNS presents a potential therapeutic strategy for enhancing cognitive function in epilepsy.